Ukulinganiswa kobuningi besikhathi sangempela kuyindlela entsha ebalulekile enqubweni yokukhiqiza ipulasitiki ebolayo. Amamitha obuningi be-Lonnmeter alinganisa ubuningi be-propylene ewuketshezi kanye nama-slurries ngokufundwa okuqhubekayo nokunembile kakhulu. Lokhu kuqapha kwesikhathi sangempela kwenza opharetha bakwazi ukuphendula ngokushesha ekuphambukeni, balungise amazinga okuphakelayo noma izimo zenqubo ukuze kugcinwe i-polymerization ngaphakathi kwezidingo.
Isifinyezo esiphezulu
Inqubo yokukhiqiza ipulasitiki ebolayo imele ikhambi elibalulekile enkingeni ekhulayo yokungcoliswa kwemvelo yipulasitiki eqhubekayo esekelwe kuphethiloli. Ihlose ukukhiqizwa okusimeme ngokuguqula izinsiza ezivuselelekayo, njenge-lignin evela embonini ye-pulp nephepha, ibe ama-polymer anobungani nemvelo anezakhiwo eziklanywe kahle kanye namazinga okuwohloka alawulwayo. Le nsimu ihlanganisa izigaba eziningana ezibalulekile, kusukela ekukhetheni izinto zokusetshenziswa kanye nokuguqulwa kwamakhemikhali, ngokusebenzisa izindlela ezithuthukisiwe ze-polymerization, kuya ekuguqulweni kube yizimpahla eziqediwe ngokusebenzisa amasu akhethekile okubumba.
Ipulasitiki Ebolayo
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Ingqikithi yenqubo yokukhiqiza ipulasitiki ebolayo ilele ezindleleni ezimbili eziyinhloko ze-polymerization: i-condensation polymerization kanye ne-ring-opening polymerization (ROP). Lokhu kuvumela ukulawula okunembile phezu kwesisindo sama-molecule kanye nesakhiwo sezinto ezibonakalayo, okubalulekile ekuhleleni i-biodegradation kanye nokusebenza kwemishini. Ubuchwepheshe bamuva bugxile kakhulu ekuhlanganiseni i-lignin kuma-matrices e-polyester, kusetshenziswa i-graft-onto kanye ne-graft-from copolymerization ukuthuthukisa kokubili amandla okudonsa kanye nokuwohloka kokuphela kokuphila. Ukuhlanganiswa ngezinhlelo zokugeleza ezisekelwe ku-microreactor kusetha indinganiso entsha yokusebenza kahle. Ngokungafani nezindlela zendabuko ze-batch, ama-microreactor anikeza ukulawula okushisa okumangalisayo nokuxuba, okukhulisa isivinini se-polymerization ngenkathi kunciphisa ukusetshenziswa kwamandla, kanye nokuqeda ama-catalyst ensimbi anobuthi ukuze kusetshenziswe ezinye izindlela ezinobungani nemvelo. Umphumela uwukuvunwa okuqhubekayo kwama-polymers anokufana okuthuthukisiwe kanye nomthelela oncishisiwe wemvelo.
Inkimbinkimbi eyinhloko yokwandisa inqubo yokukhiqiza ipulasitiki ebolayo ivela ekuguquleni impumelelo yelabhorethri ibe ukukhiqizwa okuthembekile, okukhulu. Ukwamukelwa kwezimboni kuncike ekulawulweni kwekhwalithi okuqinile, ngesikhathi sangempela. Inselele eyodwa eqhubekayo ukuqinisekisa ukusatshalaliswa kwesisindo sama-molecule okufanayo kuyo yonke imisebenzi yokukhiqiza, okubalulekile ekubikezelweni kokusebenza kanye nokuvunyelwa komthetho. Ngokufanayo, izakhiwo zemishini nezokushisa kumele zihambisane nezidingo eziqinile zokupakisha, izimpahla zabathengi, namafilimu ezolimo.
Ukuqapha ukwenziwa kwe-polymerization nokulawula inqubo yokwenza ipulasitiki ebolayo kuthuthuke ngamathuluzi okulinganisa ngokunemba. Amamitha okuqina angaphakathi kanye ne-viscosity, njengalawo akhiqizwa yiLonnmeter, adlala indima ebalulekile ekuqapheni ngesikhathi sangempela ngesikhathi se-propylene slurry noma i-bulk polymerizations. Lawa mathuluzi avumela ukulinganiswa okuqhubekayo kokuqina kwe-propylene ewuketshezi kanye ne-viscosity, okwenza kube nokulungiswa okusheshayo kwamapharamitha okufaka. Ukuqapha ukuqina kwe-propylene ngesikhathi sangempela kunegalelo ekugcineni ukuhambisana kwe-batch, ukuthuthukisa ukusetshenziswa kwe-catalyst, nokuqinisekisa izakhiwo eziqondiwe ze-polymer - isihluthulelo sokunciphisa imfucuza kanye nokweqisa kwezindleko ngenkathi kuhlangatshezwana nezinhloso zokusimama. Amamitha okuqina kwe-propylene aqondile nawo asekela ukuzenzekela kwenqubo kanye nemibhalo edingekayo ukuze kulandelwe imithetho ezindleleni zokwenziwa kwepulasitiki ebolayo ezisetshenziswa imboni.
Naphezu kwempumelelo ephawulekayo, ukwandisa inqubo yepulasitiki ebolayo kuyaqhubeka nokubhekana nezingqinamba. Ukuhlinzekwa kwezinsiza ezisezingeni eliphezulu ezisekelwe ku-bio, ukuhlanganiswa kwe-chemistry eluhlaza kuzo zonke izigaba, kanye nesidingo sezindlela zokuhlola nokuqapha ezithuthukisiwe kudinga ukunakwa okuqhubekayo. Ukukhetha amasu okubumba ipulasitiki ebolayo afanele kanye nezinqubo zokujova kumele kuqinisekise hhayi kuphela ukusebenza kokusetshenziswa kokugcina, kodwa futhi nokuphazamiseka kokuphela kokuphila ezindaweni zangempela - inhloso isalungiswa ngokusekelwa ubuchwepheshe bokuhlola nokuqapha obuthuthukisiwe.
Ngamafuphi, izinto ezintsha ekupholimeni okuqhubekayo kokugeleza, ukusetshenziswa okunesu kwe-lignin kanye nokufakwayo okuvuselelekayo, kanye nokulawulwa kobuningi be-slurry ngesikhathi sangempela kubonisa isimo esishintshayo sokukhiqizwa kwepulasitiki enobungani nemvelo. Ukuhlangana kwalezi ntuthuko kusekela intuthuko yomkhakha ekukhiqizeni amapulasitiki abola kalula, asebenza kahle kakhulu, futhi ahlala isikhathi eside.
Amapulasitiki Abolayo Nendima Yawo Ekukhiqizeni Kwanamuhla
Amapulasitiki abolayo ayizinto ezibunjiwe ze-polymeric ezenzelwe ukuwohloka ngesenzo sezinto eziphilayo—okungukuthi, ukwakheka kwezinto ezincane ezifana namabhaktheriya, isikhunta, noma ulwelwe. Lokhu kuwohloka kuveza imikhiqizo yokugcina engenabungozi emvelweni njengamanzi, i-carbon dioxide, i-methane (ngaphansi kwezimo ze-anaerobic), kanye ne-biomass. Ngokungafani nama-polymer avamile, atholakala kumakhemikhali e-petrochemical futhi amelana nokuwohloka kwemvelo, amapulasitiki abolayo aqukethe ukuxhumana kwamakhemikhali okusengozini yokuqhekeka kwamagciwane kanye ne-enzymatic, kanye ne-hydrolysis.
Umehluko phakathi kwamapulasitiki abolayo kanye nama-polymer avamile usekelwe ekwakhiweni kwawo kwamakhemikhali. Amapulasitiki avamile, njenge-polyethylene (PE) kanye ne-polypropylene (PP), anezinsika ze-carbon-carbon eziqinile ezine-crystallinity ephezulu kanye ne-hydrophobicity, okwenza ziqine kakhulu futhi zingaboli. Lezi zinto zihlala emvelweni amashumi eminyaka noma ngaphezulu, ziqhekeka kuphela ngokubola kancane kwe-photo noma i-thermal oxidation enganciphisi kakhulu umthelela wazo emvelweni. Ngokuphambene nalokho, ama-polymer abolayo avame ukuba nezibopho ze-hydrolyzable ester, amide, noma i-glycosidic emhlane wazo, okusheshisa kakhulu ukubola lapho evezwa ezintweni ezifanele zemvelo nezebhayoloji. Isibonelo, i-polylactic acid (PLA) kanye ne-polyhydroxyalkanoates (PHA) zifaka izibopho ezinjalo eziqhekekayo, okuvumela ukuqhekeka ngokusebenzisa i-hydrolysis kanye nesenzo se-microbial enzymatic.
Amapulasitiki abolayo angahlukaniswa ngokwekhemikhali yawo kanye nezinto zokusetshenziswa. I-PLA ingenye yezindawo ezibaluleke kakhulu kwezentengiselwano, ekhiqizwa ngokubiliswa kwezinsiza ezivuselelekayo njengesitashi sommbila noma umoba. Isakhiwo sayo, i-polyester eqondile ehlanganiswe yizibopho ze-ester, ithanda ukuwohloka kwe-hydrolytic—nakuba ikakhulukazi ngaphansi kwamazinga okushisa aphezulu kanye nomswakama ojwayelekile wokwenza umquba ezimbonini. I-PHA, ekhiqizwa ama-microorganisms avela ezitshalweni zokudla eziphilayo ezifana namafutha emifino noma izitashi, inesakhiwo esifanayo se-polyester kodwa inikeza ukuwohloka okusheshayo kokubili ezindaweni zomhlabathi nasemanzini. I-Polybutylene succinate (PBS) kanye ne-poly(butylene adipate-co-terephthalate) (PBAT) nazo ziyi-polyester ezibolayo ezibalulekile; I-PBS ivame ukutholakala ku-succinic acid kanye ne-butanediol etholakala ezitshalweni zokudla, kuyilapho i-PBAT iyi-co-polyester ehlanganisa amayunithi abolayo kanye ne-aromatic ukuze kulungiswe kahle izakhiwo zemishini kanye ne-kinetics yokuwohloka.
Amapulasitiki asekelwe kusitashi asetshenziswa kabanzi, akhiwe ngokuxuba isitashi semvelo—ikakhulukazi esakhiwa ama-polysaccharide e-amylose ne-amylopectin—nezinye ama-polymers abola noma avamile ukuze kuthuthukiswe ukusebenza kanye nokucutshungulwa. Ukuwohloka kwawo kuncike kuma-enzyme amagciwane ahlukanisa izibopho ze-glycosidic, okuholela ekuwohlokeni kwemvelo okusheshayo uma kuqhathaniswa ngaphansi kwezimo ezifanele.
Ukushintshela kumapulasitiki abolayo ekukhiqizeni kunikeza izinzuzo eziningi zemvelo nezokusebenza. Okokuqala nokubaluleke kakhulu, lezi zinto zinciphisa umthwalo wemfucuza yepulasitiki oqhubekayo, njengoba imikhiqizo yazo yokuwohloka ihlanganiswa kakhulu nemijikelezo yemvelo ye-biogeochemical. Lokhu kubaluleke kakhulu njengoba izingcindezi zomthetho zomhlaba wonke kanye nezomphakathi zanda ukubhekana nokungcoliswa kwepulasitiki kanye nama-microplastic. Ngaphezu kwalokho, amapulasitiki amaningi abolayo asebenzisa izitsha zokudla ezivuselelekayo, ezinganciphisa ukukhishwa kwamagesi okushisa ukushisa futhi zinciphise ukuthembela emithonjeni yakudala elinganiselwe.
Ngokombono wokucubungula, amapulasitiki abolayo ayasebenziseka futhi ayahambisana nezindlela zokwakha i-polymer ezisunguliwe, njengokubumba ngemijovo kanye nokukhipha. Amasu afana nokubumba ngemijovo yepulasitiki abolayo kanye nezinye izinqubo zokubumba empeleni ziwukuzivumelanisa nokucubungula okuvamile kwe-thermoplastic, okuvumela ukuhlanganiswa okuqondile engqalasizinda ekhona yokupakisha, ezolimo, kanye nezinto ezisetshenziswa kanye.
Ngokokusebenza, ukulawulwa kwekhwalithi ngesikhathi sangempela ekukhiqizweni kwamapulasitiki abolayo kubalulekile, ikakhulukazi uma kusetshenziswa izitsha zokudla ezisekelwe ku-bio kanye neziguquguqukayo. Amathuluzi okulinganisa angaphakathi, njengemitha yobuningi evela eLonnmeter, enza kube lula ukulinganisa okuqhubekayo kwe-propylene density ngesikhathi sangempela kanye nokulawulwa kwe-propylene slurry polymerization. Ukuqapha okunembile kwamapharamitha abalulekile njengokuqina kwe-propylene ewuketshezi kanye nezimo zenqubo ye-polymerization kuqinisekisa ikhwalithi ye-polymer ehambisanayo, ukusebenza kahle komshini, kanye namazinga okubola okubikezelwayo. Lolu hlobo lokulawula inqubo luyingxenye ebalulekile yokukhiqizwa kwe-polymer yesimanje ebolayo, okuvikela kokubili izakhiwo zezinto kanye nokuhambisana nezindinganiso zokusebenza noma zokuba ngumquba.
Izifundo zemvelo ezivela eminyakeni emibili edlule ziqokomisa ukuqonda okuyisisekelo: ijubane langempela kanye nokuphelela kokubola kwezinto eziphilayo akuxhomekile kuphela esakhiweni se-polymer kodwa futhi nasesimweni semvelo. Isibonelo, i-PLA idinga amazinga okushisa okwenziwa komquba wezimboni ukuze kuqhekeke ngokushesha, kuyilapho i-PHA kanye namapulasitiki athile asekelwe kusitashi ewohloka ngokushesha enhlabathini yemvelo noma ezimweni zasolwandle. Ngakho-ke izinzuzo zangempela zemvelo zixhunyaniswe kokubili ekukhetheni ikhemistri ye-polymer efanele kanye nokusungulwa kwengqalasizinda yokusekela ukuphathwa kwemfucuza.
Ukwamukelwa kwamapulasitiki abolayo kuvula amathuba amasha okuklama umkhiqizo ozinzile kanye nezinketho zokugcina impilo ngendlela efanele, ikakhulukazi uma kuhlanganiswa nokuqapha inqubo eqinile, ukusetshenziswa kahle kwempahla yokudla, kanye nokukhetha izinto ezinolwazi. Ukuhlanganiswa kwazo ngempumelelo ekukhiqizeni kwanamuhla kuncike ekuqondeni okuphelele kokubili ikhemikhali yazo kanye nenqubo yokukhiqiza ipulasitiki abolayo, kanye nokuphathwa ngendlela efanele kuzo zonke izigaba zokukhiqiza, ukusetshenziswa, kanye nokulahla.
Ukukhethwa Nokulungiswa Kwezinto Ezingavuthiwe
Ukukhethwa kokudla okusimeme nokuvuselelekayo kuyisisekelo senqubo yokukhiqiza ipulasitiki ebolayo. Lezi zindlela zidinga ukuhlolwa komjikelezo wokuphila okuqinile (i-LCA) ukuqinisekisa ukukhishwa kwamagesi okushisa okunciphisayo, ukusetshenziswa komhlaba namanzi okuncishisiwe, kanye nokubola kokuphela kokuphila okuphumelelayo. Ama-LCA anamuhla abheka ukutshalwa, ukuvuna, ukucubungula, kanye nemiphumela engezansi, ukuqinisekisa ukuthi ukutholakala kwezinto ezifana nezinsalela zezolimo, i-biomass engadliwayo, noma imfucuza yezinto eziphilayo kunikeza izinzuzo ezibonakalayo zemvelo.
Izitsha zokudla kumele zigweme ukuncintisana nokunikezwa kokudla. Izinto ezifana notshani be-switchgrass, i-miscanthus, ama-crop husk, uwoyela wokupheka ongcolile, noma i-textile waste-derived cellulose zithandwa kakhulu. Lokhu akugcini nje ngokukhuthaza imikhuba yezomnotho ojikelezayo kodwa kunciphisa kakhulu umthelela wemvelo kanye nezindleko zezinto zokusetshenziswa uma kuqhathaniswa nommbila noma umoba. Abakhiqizi kumele futhi baqinisekise ukuthi ukukhethwa kwezitshalo kanye nesidingo esikhulu akubangeli ushintsho olungaqondile lokusetshenziswa komhlaba, njengokugawulwa kwamahlathi noma ukulahlekelwa kwezinto eziphilayo. Ukulandelela, ngemibhalo kusukela emthonjeni kuya ku-polymerization, sekuyinto ejwayelekile kubathengi nabalawuli ukuqinisekisa izintambo zokuphakelwa ezinomthwalo wemfanelo.
Ukukhiqizwa kwepulasitiki ebolayo kuhlanganisa nokuzinza kwezenhlalo nakwezomnotho njengezilinganiso ezibalulekile zokukhetha. Izitsha zokudla kumele zitholakale nobufakazi obuqinisekisiwe bezimo zokusebenza ezifanele kanye nezinzuzo emiphakathini yendawo. Izinhlelo zokuzithandela kanye nokuhlolwa kwezinkampani zangaphandle kuvame ukudingeka ngaphambi kokuvunyelwa.
Ukuvuselelwa okusheshayo kubalulekile. Izitshalo zaminyaka yonke, imikhiqizo engaphansi kwezolimo, kanye nezinto ezigcwalisa kabusha ngokushesha njenge-algae noma utshani kuya ngokuya kuba yinto ejwayelekile ngenxa yamazinga azo okuvuselelwa okusheshayo kanye nezingozi ezimbalwa zokuphazamiseka kwemvelo. Ukudla okuphakelayo kumele futhi kutshalwe futhi kucutshungulwe nge-chemical footprint encane eyingozi; ukusetshenziswa kwezibulala-zinambuzane kanye nokungcola okuqhubekayo kwezinto eziphilayo kunqunyelwe kakhulu, kanye noshintsho olukhulayo oluya ekulimeni kwezinto eziphilayo kanye nokuphathwa kwezinambuzane okuhlanganisiwe.
Ukubeka phambili imfucuza kanye nemithombo engaphansi kwemikhiqizo kuvumelanisa inqubo yokukhiqiza ipulasitiki ebolayo nezinqubo ezibanzi zokukhiqiza ipulasitiki enobungani nemvelo. Lokhu kuhilela ukusebenzisa imikhiqizo engaphansi kwemikhiqizo engemva kwezimboni noma engemva kokusetshenziswa, ukushayela ukusebenza kahle kwezinsizakusebenza, kanye nokusekela umnotho ojikelezayo.
Ngemva kokukhetha, izinyathelo zangaphambi kokucubungula zibalulekile ukuze kuthuthukiswe ukukhishwa kwe-monomer kanye nokuhlanzeka. Izinsalela zezolimo, isibonelo, zidinga ukugaya, ukomisa, kanye nokuhlukaniswa ngaphambi kokuba i-hydrolysis ikhiqize ushukela ovundayo. Izitshalo ezicebile ngesitashi zidlula ekugayweni nasekuphathweni nge-enzyme ukuze kugaywe ama-carbohydrate ayinkimbinkimbi. Ukuze kutholakale ukudla kwe-cellulose, ukugaya ngamakhemikhali noma ngomshini kususa i-lignin futhi kuthuthukisa ukucutshungulwa. Isinyathelo ngasinye sihlose ukukhishwa okuphezulu kwama-monomer asebenzisekayo njenge-lactic acid, okubalulekile ezindleleni zokwenziwa kwepulasitiki ebolayo ekhiqiza kakhulu kanye nezinqubo ze-polymerization zepulasitiki ezingezansi.
Izitsha zokudla ezicutshungulwe kusengaphambili ziqashwe ngokucophelela ukuze kutholakale ukwakheka, okuqukethwe okungcolile, kanye nomswakama. Lokhu kuqinisekisa ikhwalithi yokufaka ehambisanayo kanye nokusebenza okuthembekile ezinyathelweni ezilandelayo zokuguqulwa kwamakhemikhali noma kokubilisa—okuthinta ngqo ukuzinza kwenqubo, isivuno sokusabela, kanye nokukhula okuphelele kokukhiqizwa kwepulasitiki ebolayo. Ngakho-ke, ukwenza ngcono izitsha zokudla akugcini nje ngokuba yimfuneko yemvelo; kubalulekile ekugcineni ukusebenza kahle kanye nokukhiqiza kuzo zonke izigaba zenqubo ezansi.
Ukubumba Nokubumba: Kusukela Ezihlanganisweni Kuya Ezimpahleni Eziqediwe
Ukubumba Umjovo Wepulasitiki Obolayo
Ukubumba umjovo wepulasitiki ebolayo kuncike ekulethweni okunembile kwama-resin ancibilikisiwe—njenge-PLA, i-PHA, ne-PBS—emgodini omile, lapho izinto ziphola khona futhi zithatha i-geometry yokugcina. Le nqubo idinga ukunakwa okuqinile enkambisweni yokukhiqiza ipulasitiki ebolayo futhi ifaka imikhuba ethile emihle ngenxa yokuzwela kwamakhemikhali nokushisa kwalezi zinto.
Izikhunta ze-Polylactic acid (PLA) ziphakathi kuka-160 no-200 °C, kodwa imiphumela emihle kakhulu itholakala ku-170–185 °C. Ukudlula lawa mazinga okushisa kuyingozi yokuqhekeka kweketanga, ukulahleka kwesisindo sama-molecule, kanye nokwehla kokusebenza komshini. Izinga lokushisa lesikhunta ngokuvamile ligcinwa phakathi kuka-25 no-60 °C. Izinga lokushisa eliphezulu lesikhunta, kusukela ku-40 kuya ku-60 °C, landisa ubukristalu futhi lithuthukise amandla omshini, kuyilapho ukupholisa okusheshayo ngaphansi kuka-25 °C kungadala ukucindezeleka kwangaphakathi kanye nokwakheka kwekristalu okubi. Izingcindezi zomjovo zivame ukusuka ku-60 kuya ku-120 MPa—okwanele ukuqinisekisa ukugcwaliswa kwesikhunta ngenkathi kugwenywa ukukhanya. I-viscosity ephansi ye-PLA ivumela isivinini esimaphakathi, igweme izingozi zokusika okuphezulu okonakalisa i-polymer. Okubaluleke kakhulu, i-PLA kumele yomiswe kahle ngaphansi komswakama ongu-200 ppm (amahora angu-2–4 ku-80–100 °C). Noma yikuphi okuqukethwe kwamanzi okweqile kubangela ukuwohloka kwe-hydrolytic, okuholela ezingxenyeni ezibuthakathaka nezingasebenzi kahle.
Ama-resin e-PHA, njenge-PHB ne-PHBV, anezidingo ezifanayo zokucubungula ukushisa okulawulwayo. Abumba kangcono phakathi kuka-160 no-180 °C. Emazingeni okushisa angaphezu kuka-200 °C, ama-PHA abola ngokushesha. Abacubunguli kufanele basebenzise amazinga okushisa esikhunta aphakathi kuka-30 no-60 °C. Ingcindezi yomjovo ivame ukusuka ku-80 kuya ku-130 MPa futhi incike ekwakhiweni kwe-copolymer kanye nengxube. Njenge-PLA, ama-PHA azwela kakhulu emanzini asele futhi adinga ukomiswa ku-60-80 °C ukuze kube namazinga omswakama angaphansi kuka-500 ppm. Ijubane lomjovo elihamba kancane linciphisa ukuwohloka kokucheba, okugcina ubuqotho beketanga le-polymer.
Ama-resin e-PBS, yize eqinile kakhulu ekushiseni kune-PLA noma i-PHA, asadinga ukucutshungulwa kokuncibilika okuphakathi kuka-120 no-140 °C. Ukucutshungulwa emazingeni okushisa aphezulu (> 160 °C) kungalimaza i-matrix. Amazinga okushisa esikhunta angu-20–40 °C avamile; amazinga okushisa aphezulu asiza ukwakheka kwekristalu, athuthukise ukuzinza kobukhulu bento ebunjiwe. Ububanzi bokucindezela obujwayelekile bungu-80–100 MPa. I-PBS ingabekezelela umswakama wokuqala ophezulu kune-PLA, kodwa kufanele isabekwe endaweni engaba ngu-80 °C ngaphambi kokubumba.
Izinto ezicatshangelwayo zokucubungula ezihlukile kuzo zonke lezi zinto zifaka phakathi ukuzwela kokubili isikhathi sokuhlala kanye nokumuncwa komswakama. Isikhathi eside emgqonyeni noma esikhumbeni emazingeni okushisa aphezulu kusheshisa ukuwohloka, kudala amaphutha njengokushintsha kombala, ukuqhekeka, kanye nephunga. Ukuphathwa komswakama okufanele, okufezwa ngokusomisa ngaphambi kokumiswa, kubalulekile kuzo zonke izinyathelo zenqubo yokwenza ipulasitiki ebolayo. Amathuluzi okuqapha ngesikhathi sangempela, njengemitha yobuningi obungaphakathi kanye namamitha e-viscosity angaphakathi akhiqizwe yi-Lonnmeter, asiza ukugcina ukuhambisana kwezinto ngokuveza ukuphambuka kwezakhiwo zokuncibilika ngenxa yokushintshashintsha kwezinga lokushisa noma komswakama.
Amaphutha avamile okubumba ama-resin abolayo afaka phakathi i-splay (evela kumswakama owedlulele), ukuphuka okubuthakathaka (okubangelwa ukoma ngokweqile noma izinga lokushisa eliphakeme kakhulu), kanye nokungagcwali kahle noma ukugcwaliswa okungaphelele (okuvela ekushiseni okuphansi kwesikhunta noma ingcindezi ephansi). Uma kuvela i-splay, sebenzisa ukomisa okuqinile. Uma kuvela imifantu noma ukuqhekeka, yehlisa izinga lokushisa lokuncibilika bese unciphisa isikhathi sokuhlala. Ama-voids avame ukuphendula ekucindezelweni okuphezulu komjovo noma ukwanda okuncane kwezinga lokushisa lokuncibilika.
Izifundo zibonisa ukuthi ukwenza ngcono amazinga okushisa kwesikhunta kuholela ezimpahleni ezithuthukisiwe zemishini nezomphezulu ze-PLA ne-PBS, kuyilapho ukunciphisa isikhathi sokuhlala esincibilikisiwe kulondoloza kakhulu isisindo sama-molecule sama-resin e-PHA. Izikhathi zomjikelezo, amapharamitha okomisa, kanye nokuqapha okusenquboni kusalokhu kubalulekile ekukhiqizweni okungenamaphutha kwezingxenye zepulasitiki ezibolayo.
Amanye Amasu Okuguqula
Ngale kokubumba ngomjovo, izindlela eziningana zibalulekile ezinyathelweni zokukhiqiza izinto zepulasitiki ezibolayo, ngayinye ilungiselelwe ukusebenza okuthile kanye nezidingo zokuhlanganiswa komquba.
Ukukhipha kubumba ipulasitiki ngokuphoqa i-polymer encibilikisiwe ngedayi, kwenze amaphrofayili, amashubhu, namashidi. Enqubweni yepulasitiki ebolayo, ukukhipha kukhiqiza amashidi e-PLA okulungisa ukushisa noma ama-pellet e-PBS ukuze asetshenziswe kamuva. Isihluthulelo sekhwalithi ubuningi bokuncibilika obufanayo, obuqashwe ngamamitha obuningi besikhathi sangempela njengalawo avela eLonnmeter, okuqinisekisa ukugeleza okuhambisanayo kanye nobukhulu bodonga.
Ukufuthwa kwefilimu kwakha amafilimu amancane abolayo (ezikhwama noma okupakishwa) ngokukhipha i-resin nge-die eyindilinga bese kuyandisa ibe yibhamuza. Ukulawula izinga lokushisa kanye nesivinini sokugeleza lapha kubalulekile ukuze kube nobukhulu obulinganayo kanye nokuqina komshini, ikakhulukazi njengoba ama-resin abolayo avame ukuzwela ekushintsheni komswakama kanye nokushisa.
I-thermoforming ifudumeza amashidi epulasitiki abolayo—ngokuvamile i-PLA—kuze kube yilapho egobeka, bese iwacindezela ezikhumbeni ukuze kudalwe ithileyi, indebe, noma izimo zesivalo. Ukucubungula ngempumelelo kuncike ekujiyeni kweshidi okufanayo kanye nokomiswa kwangaphambili kwamafilimu okufaka ukuze kuvinjelwe amabhamuza angaphakathi kanye nezindawo ezibuthakathaka.
Ukubumba nge-blow kudala izinto ezingenalutho njengamabhodlela nezitsha. Kumapulasitiki abolayo njenge-PBS, ukulawula ngokucophelela amandla okuncibilika kanye nokushisa kwe-parison (preform) kubalulekile ngoba lezi zinto zingaba bucayi kakhulu ekugobeni nasekuqondeni okungalingani ngesikhathi sokuvunguza.
Indlela ngayinye yokuguqula kufanele ifaniswe ne-resin kanye nomkhiqizo owufunayo. Ukuze kube nokubumba okuphezulu kanye nokusebenza kahle, khetha inqubo evumelanisa izidingo zokushisa, zemishini, kanye ne-crystallization ze-polymer ne-geometry yengxenye yokugcina kanye ne-use-case. Ukusebenzisa ukuqapha ubuningi besikhathi sangempela ku-inthanethi kulo lonke ukukhiqizwa kwe-extrusion, ishidi, noma ibhodlela kuqinisekisa ukuhambisana komkhiqizo futhi kunciphisa imfucuza.
Ukuvumelanisa kahle inqubo nomkhiqizo—kungakhathaliseki ukuthi ngokusebenzisa ukubumba kwepulasitiki ebolayo, ukukhipha, ukuvunguza ifilimu, ukufudumala, noma ukubumba nge-blow—kuqinisekisa ukuthi amasu okukhiqiza ipulasitiki ebolayo ahlangabezana nokulindelwe kwemvelo kanye nekhwalithi. Yonke indlela kumele icabangele ngokufanele ukuzwela kwe-biopolymer okuhlukile, ngokuqapha, ukomisa, kanye nokulawula izinga lokushisa okufakwe enkambisweni yokukhiqiza ipulasitiki ebolayo.
Ukuthuthukisa Inqubo: Ukuqapha Nokulawula Izakhiwo Ze-Polymer
Ukulawulwa kwenqubo eqinile kubalulekile enkambisweni yokukhiqiza ipulasitiki ebolayo, okulawula izakhiwo zokugcina ze-polymer njengamandla omshini, ukubola kwayo, kanye nokuphepha. Ukufeza ukubola kwayo kanye nokuhlanganiswa kwayo okuhle kusho ukulawula eduze amapharamitha abalulekile: izinga lokushisa, ingcindezi, isikhathi sokuphendula, kanye nobumsulwa bazo zonke izinto ezifakiwe.
Izinga lokushisa kumele lilawulwe ngokunembile. Ukuphambuka kungashintsha isisindo sama-molecule e-polymer, ubukristali, kanye nokusebenza kwayo. Ukushisa okweqile kungabangela ukuqhekeka kweketanga noma ukonakalisa ama-monomer azwelayo, okuholela kumapulasitiki abuthakathaka noma angaguquki abolayo. Ngokuphambene nalokho, amazinga okushisa aphansi kakhulu avimbela ukuguqulwa kwama-monomer, okudinga izikhathi zokusabela ezinde ezingasebenzi kahle futhi kubeke engcupheni ukusabela okungaphelele.
Imithelela yokucindezela ibonakala ezinqubweni ezisebenzisa ama-monomers aguquguqukayo noma ama-polymerization esigaba segesi, njengakwi-polymerization ye-propylene. Ukucindezela okuphezulu kungakhuphula amazinga okusabela kanye nesisindo sama-molecule e-polymer, kodwa ukucindezela ngokweqile kwandisa izingozi zokwehluleka kwemishini kanye nokusabela okungafuneki. Kwezinye izinqubo, njenge-polycondensation, ukucindezela okungaphansi komoya kusiza ukususa imikhiqizo engaphandle futhi kuqhubekisele phambili ukusabela ekuqedeni.
Isinyathelo ngasinye enkambisweni yokwenza ipulasitiki ebolayo sincike kakhulu ekuhlanzekeni okuphelele kwama-monomer, ama-catalyst, kanye nezinyibilikisi. Ngisho nomswakama omncane noma ukungcola kwensimbi kungabangela ukusabela okungekuhle, kuqalise ukuqedwa kweketanga ngaphambi kwesikhathi, noma ama-catalyst anobuthi. Izinqubo zezimboni zifaka phakathi ukuhlanzwa okuqinile kwezinto ezifakwayo kanye nokuhlanza ngokucophelela yonke imishini yenqubo ukuze kuvikelwe umkhiqizo ohambisanayo nosezingeni eliphezulu.
Ubuningi be-slurry buyipharamitha ebalulekile, ikakhulukazi ku-propylene polymerization—indlela evamile ekukhiqizweni kwama-resin e-polymer abola. Ukugcina ubuningi obuhle kakhulu ku-slurry ye-polymerization kuthinta ngqo i-reaction kinetics kanye, ekugcineni, nezakhiwo zezinto ezibonakalayo.
Inzuzo yokulinganisa ku-inthanethi, ngesikhathi sangempela ngeimitha yobuningi be-propylenekukabili. Okokuqala, abaqhubi bangafinyelela ikhwalithi yomkhiqizo ezinzile ngedatha engaphazanyiswa ku-ukuminyana kwe-propylene yoketsheziOkwesibili, ukutholakala okusheshayo kokuguquguquka kobuningi kuvumela ukulungiswa ngesikhathi—ukuvimbela ukukhiqizwa kwamaqoqo angacacisiwe noma alahlekile. Impendulo enjalo yenqubo eqondile ibalulekile ekugcineni ikhwalithi ye-polymer efanayo, ikakhulukazi emigqeni yokukhiqiza eqhubekayo nekhiqizayo ephezulu.
Ukuhlanganisa amamitha obuningi njengalawo akhiqizwa yiLonnmeter ku-reactor ye-polymerization noma i-compounding extruder kunikeza ithuluzi elinamandla lokwenza ngcono inqubo eqhubekayo. Ngokulandela izitayela zobuningi kuyo yonke inqubo yokukhiqiza, abakhiqizi bangahlaziya ngokwezibalo inqubo, babeke ama-alamu enqubo anembe kakhudlwana, futhi basebenzise amasu okulawula ahlelwe kahle. Lokhu kunciphisa imfucuza yezinto zokusetshenziswa, kwandisa umkhiqizo, futhi kusekela ngqo imigomo yezinhlelo zokukhiqiza ipulasitiki ezinobungani nemvelo.
Izinhlelo zokuqapha ubuningi be-propylene zesikhathi sangempela zinomthelela oqinisekisiwe. Lapho ubuningi be-propylene obuyiketshezi bulawulwa ngokuqinile, ukuhambisana kwe-resin kuyathuthuka futhi ukuphazamiseka kwenqubo kuyancishiswa. Impendulo esheshayo evela kumamitha obuningi isho ukuthi onjiniyela bezinqubo bangagwema ukudubula ngokweqile, banciphise kokubili ukuguquguquka kanye nokusetshenziswa ngokweqile kwamandla nezinto zokusetshenziswa. Lawa masu okulawula manje abhekwa njengomkhuba omuhle kakhulu ekwakhiweni kwepulasitiki okubolayo kwesimanje kanye nemigqa ehlanganisiwe.
Ukuhlanganiswa kwalezi zinsimbi zesikhathi sangempela kusekela ukuthuthuka okuqhubekayo ezinyathelweni zokukhiqiza ipulasitiki ebolayo, okuveza ukuziphatha okuphinda kukhiqizwe ngomshini, okushisayo, kanye nokubola kuzo zonke izindawo zokukhiqiza. Lo mgogodla wokulawula oqondile ubalulekile njengoba amazinga okulawula, okuphepha, kanye nemakethe yama-polymer abolayo ehlala eqina.
Izinselele Zokuthuthukisa Ukukhiqizwa Kwepulasitiki Ebolayo Kwezimboni
Ukuthuthukisa inqubo yokukhiqiza amapulasitiki abolayo kubhekene nezithiyo ezibanzi zochungechunge lwenani, kusukela ezindleko zokudla kanye nokutholakala kwawo. Iningi lamasu okukhiqiza ipulasitiki abolayo lincike ezintweni zokusetshenziswa zezolimo ezifana nommbila, umoba, kanye nomdumbula. Amanani abo ayashintshashintsha ngenxa yokushintsha kwezimakethe zezimpahla, isimo sezulu esingalindelekile, ukushintsha kwesivuno sezitshalo, kanye nezinqubomgomo zezolimo kanye ne-biofuel ezishintshayo. Lezi zici zihlanganisa ukuphazamisa ukuzinza komnotho kwenqubo yokukhiqiza ipulasitiki abolayo, kuthinta isinyathelo ngasinye kusukela ekuthengweni kokudla kuya ekubunjweni kwe-polymerization kanye nokubumba.
Ukuncintisana kwe-feedstock nokudla, ukudla kwezilwane, kanye nokusetshenziswa kwamandla kwenza kube nzima nakakhulu ukufinyelela izinto zokusetshenziswa. Ukuncintisana okunjalo kungabangela impikiswano ngokuphepha kokudla futhi kukhulise ukungazinzi kwamanani, okwenza kube nzima kubakhiqizi ukuqinisekisa ukutholakala okuqhubekayo nokungabizi. Ezindaweni lapho izitshalo ezithile zintuleka khona, lezi zinselele ziyanda, okuvimbela ukwandiswa komhlaba wonke kwezinqubo zokukhiqiza ipulasitiki ezinobungani nemvelo.
Ukusebenza kahle kokuguqulwa kuletha esinye isithiyo. Ukuguqula i-biomass ibe yi-monomers, futhi ekugcineni, ama-biopolymers kudinga i-feedstock esezingeni eliphezulu, engenazo izinto ezingcolile. Noma yikuphi ukushintshashintsha kunganciphisa isivuno futhi kukhulise izindleko zokucubungula. Ngisho nezinyathelo ezithuthukisiwe zokukhiqiza ipulasitiki ebolayo—njengokuvutshelwa, ukwenziwa kwe-polymerization, kanye nokubumba—zisalokhu zidinga amandla amaningi futhi zizwela ikhwalithi yokufaka. I-feedstock yesizukulwane sesibili efana nemfucuza yezolimo ibhekene nezithiyo zobuchwepheshe okuhlanganisa ukwelashwa kwangaphambi kokucubungula okuyinkimbinkimbi kanye namazinga okuguqulwa aphansi.
Izinselele zezokuthutha zengeza izingqimba zobunzima. Ukuqoqwa kwempahla yokudla, ukugcinwa kwayo, kanye nokuthuthwa kwayo kuncike engqalasizinda ebanzi, ikakhulukazi ekusingatheni i-biomass engeyona yokudla. Isikhathi sokuvuna sonyaka singabangela ukwanda okungazelelwe kwezindleko zezinto ezibonakalayo noma ukuphazamiseka kokuhlinzekwa. Ukuphatha, ukomisa, kanye nokulungisa i-biomass kusengaphambili kudinga ukutshalwa kwezimali engqalasizinda ekhethekile, okuholela ezinqubweni ezingajwayelekile nezibiza kakhulu eziphonsela inselelo ukugeleza okuqhubekayo okudingekayo ekukhiqizweni kwe-polymer okusekelwe ku-bio okukhulu.
Ukuhlangabezana nezidingo zamakhasimende ezahlukahlukene kanye nezinhlelo zokusebenza ezithile kudala izingcindezi ezengeziwe. Izinhlelo zokusebenza zidinga imingcele ehlukene yenqubo yokukhiqiza i-polymer ebolayo, njengamandla okudonsa, izinga lokubola, kanye nokuziphatha kokubumba. Ukwanelisa lokhu ngaphandle kokulahla ukubola noma ukusebenza kahle kwezindleko kunzima. Amakhasimende asemaphaketheni angase abeke phambili ukubola okusheshayo, kanti amanye, njengasezinhlelweni zezimoto, adinga ukuqina. Amasu amasha okubumba ipulasitiki ebolayo kanye nokwehluka kwenqubo kumele kulungiswe kahle kulezi zindinganiso zokusebenza ezahlukahlukene, ngokuvamile kudingeke izinqubo eziyinkimbinkimbi neziguquguqukayo kanye nokuqapha impahla ngesikhathi sangempela.
Ukulinganisela ukusebenza komkhiqizo, ukubola kwezinto eziphilayo, kanye nokukhula kwazo kuseyinselele eqhubekayo. Isibonelo, ukwandisa ukukristali kungathuthukisa amandla omkhiqizo, kodwa kunganciphisa amazinga okubola kwezinto eziphilayo. Ukushintsha izimo zokucubungula—njengesikhathi sokwenziwa kwepulasitiki noma ukubumba ngomjovo—kumele kuphathwe kahle ukuze kulondolozwe kokubili ukusebenza kwemvelo kanye nokukhiqiza ngobuningi. Izixazululo zokulinganisa eziqondile, njengemitha yobuningi bepropylene kaLonnmeter, zinikeza ukuqapha kokuqina kwepropylene ngesikhathi sangempela futhi zivumele ukulawulwa okunembile esinyathelweni sokuqina kwe-propylene polymerization slurry yenqubo yepulasitiki ebolayo, kusekela ikhwalithi yomkhiqizo eqhubekayo kanye nokusebenza okukalayo.
Okulindelwe ngokwemithetho kanye nokuxhumana okusobala kuye kwaba yinto ebalulekile enqubweni yokukhiqizwa kwepulasitiki ebolayo. Imithethonqubo ingabeka amazinga aqinile okubolayo, isikhathi sokubolayo, kanye nokusimama kwempahla yokudla. Ukuhlukanisa phakathi kwepulasitiki ebolayo, ebolayo, kanye nepulasitiki ebolayo kubalulekile, njengoba ukufaka amalebula angafanele noma izimangalo zomkhiqizo ezingacacile kungabangela izinhlawulo zomthetho futhi kuqede ukwethenjwa kwabathengi. Abakhiqizi kumele batshale imali ekulebheni okucacile kanye namadokhumenti aphelele omkhiqizo, okubonisa ukuthobela imithetho kanye neziqinisekiso ezihambisanayo ezinobungani nemvelo.
Lezi zinselele ezihlukene—izindleko ezihlanganisa, ukuphakelwa, ukusebenza kahle kokuguqulwa, ukuthuthwa kwempahla, ukuhambisana kwesicelo, ukusebenza komkhiqizo, kanye nokuhambisana nemithetho—kugcizelela ubunzima bokukhulisa inqubo yokwenza ipulasitiki ebolayo. Isinyathelo ngasinye, kusukela ekukhetheni nasekulinganisweni kwesikhathi sangempela kwezitsha zokudla ezifana ne-liquid propylene kuya ekwakhiweni kwenqubo yonke yokwenza ipulasitiki ebolayo, kuncike komunye nomunye futhi kudinga ukwenziwa ngcono okuqhubekayo kanye nokucaca kulo lonke uchungechunge lwenani.
Ukuphathwa Kwemfucuza, Ukuphela Kwempilo, kanye Neminikelo Yemvelo
Ukuwohloka kwamapulasitiki abolayo kuncike ekuhlanganisweni kwezici zemvelo kanye nezici zezinto ezibonakalayo. Izinga lokushisa lidlala indima ebalulekile; iningi lamapulasitiki abolayo, njenge-polylactic acid (PLA), liwohloka ngempumelelo kuphela emazingeni okushisa okukhiqiza umquba ezimbonini, ngokuvamile angaphezu kuka-55°C. Kula mazinga okushisa aphezulu, ama-polymer athambisa, enza kube lula ukufinyelela kwamagciwane futhi athuthukise i-enzyme hydrolysis. Ngokuphambene nalokho, emazingeni okushisa aphansi noma aphansi—njengalawo asezindaweni zokulahla udoti noma kuma-compost asekhaya—amazinga okuwohloka ehla kakhulu, futhi izinto ezifana ne-PLA zingase ziqhubeke iminyaka eminingi.
Umswakama ubaluleke ngokulinganayo. Izinhlelo zokwenza umquba zigcina umswakama ongu-40-60%, ububanzi obusekela kokubili imetabolism yamagciwane kanye nokuqhekeka kwe-hydrolytic kwamaketanga e-polymer. Amanzi asebenza njengendawo yokuthuthwa kwama-enzyme kanye ne-reactant ekuwohlokeni kwe-polymer, ikakhulukazi kuma-ester, atholakala ngobuningi kumapulasitiki abhalwe ukuthi angafakwa umquba. Umswakama onganele unciphisa wonke umsebenzi wamagciwane, kuyilapho okweqile kuguqula umquba we-aerobic ube yizimo ze-anaerobic, kuvimbela ukuqhekeka okuphumelelayo futhi kwandisa ingozi yokukhiqizwa kwe-methane.
Umsebenzi we-microbial usekela ukuguqulwa kwangempela kwama-polymer epulasitiki abe yimikhiqizo yokugcina engengozi. Ama-compost ezimboni akhuthaza imiphakathi ehlukahlukene yamabhaktheriya nesikhunta, okwenziwa ngcono ngokuphefumula nokulawula izinga lokushisa. Lawa ma-microbes akhipha uhla lwama-enzyme—ama-lipase, ama-esterase, nama-depolymerase—ahlukanisa izakhiwo ze-polymeric zibe ama-molecule amancane njenge-lactic acid noma i-adipic acid, abese eguqulwa abe yi-biomass, amanzi, kanye ne-CO₂. Ukwakheka kwe-microbial consortia kuyashintsha phakathi nenqubo yokwenza umquba: izinhlobo ze-thermophilic zibusa ekushiseni okuphezulu kodwa zinika indawo izinto eziphilayo ze-mesophilic njengoba ama-piles epholile. Isakhiwo sama-molecule epulasitiki ethile kanye ne-crystallinity nakho kudlala indima ebalulekile; isibonelo, izingxube ezisekelwe kusitashi zitholakala kalula ngokushesha kune-PLA ekristalu kakhulu.
Amapulasitiki abolayo anegalelo ekuphambukisweni kwemfucuza ngokunikeza ezinye izindlela ezenzelwe ukuwohloka okulawulwayo esikhundleni sokuqongelela. Ezimweni zokulahla imfucuza, inzuzo yawo ilinganiselwe ngaphandle kokuthi izimo zokulahla imfucuza zilungiselelwe ukubola kwemfucuza—okungavamile ngokwesiko ngenxa yokuntuleka komoya kanye nokusebenza okushisa. Kodwa-ke, uma kuqondiswa kuma-compost ezimboni, amapulasitiki abolayo aqinisekisiwe angaguqulwa abe umquba ozinzile, asuse izinto eziphilayo ezithunyelwa endaweni yokulahla imfucuza noma ekushisweni. Izindawo zasolwandle, ezibonakala ngamazinga okushisa aphansi kanye nokuhlukahluka okulinganiselwe kwamagciwane, zinciphisa amazinga okuwohloka kakhulu, ngakho-ke amapulasitiki abolayo akufanele abhekwe njengesixazululo sokulahlwa kwemfucuza olwandle kodwa kunalokho abhekwe njengendlela yokuvimbela ukuqongelela ngemva komthengi uma kunezindlela ezifanele zokulahla.
Ukuphathwa kwemfucuza yesimanje kwandisa ukwamukela amapulasitiki abolayo. Izinhlelo zokufaka umquba ezimbonini zenzelwe ukudala indawo efudumele necebile ngomswakama edingekayo ukuze kubole ngempumelelo. Lezi zinhlelo zilandela izinqubo zomhlaba wonke zokungenisa umoya, umswakama, kanye nokulawulwa kwezinga lokushisa, zilandelela iziguquguquko ngezindlela ezifana nokuqapha ngesikhathi sangempela izimo zenqwaba yomquba. Amamitha obuningi be-Lonnmeter, isibonelo, adlala indima ebalulekile ekulawuleni inqubo ngokuqinisekisa ukuhambisana kwe-feedstock kanye nokwenza ngcono ukugeleza kwezinto: ubuningi obuzinzile bubalulekile ukuhlola ukuxubana nokungenisa umoya okufanele, izinto ezithinta ngqo amazinga okuqhekeka kuma-compost.
Ukuhlanganiswa kokwenza umquba kudinga ukuthi amapulasitiki abolayo ahlonzwe futhi ahlungwe kahle. Izindawo eziningi zidinga isitifiketi sokuqina komquba ngokwezindinganiso ezimisiwe. Uma lezi zindlela zihlangatshezwa, futhi kulandelwa imigomo yokusebenza, ama-compost angacubungula amapulasitiki abolayo ngempumelelo, abuyisele ikhabhoni nezakhamzimba enhlabathini ngaleyo ndlela avale iluphu yezinto eziphilayo ngaphakathi kwenqubo yokukhiqiza ipulasitiki enobungani nemvelo.
Ukugeleza kwamapulasitiki abolayo ngalezi zinhlelo, okusekelwa idatha yenqubo enembile njengokulinganisa kwe-Lonnmeter ngesikhathi sangempela, kwenza kube nokubola okuthembekile kanye nokuphathwa kwemvelo. Kodwa-ke, umnikelo ogcwele wezemvelo awuxhomekile kuphela ekwakhiweni komkhiqizo kanye nenqubo yokukhiqiza ipulasitiki ebolayo kodwa futhi nasekuziphatheni kwabathengi kanye nokusebenza kahle kwengqalasizinda yokuphathwa kwemfucuza yendawo. Ngaphandle kokuqoqwa okusebenzayo, ukuhlonza, kanye nokwenza umquba, umjikelezo ohlosiwe—inqubo yokwenza ipulasitiki ebolayo ukuze kucebiswe inhlabathi—ungaphazanyiswa, unciphise izinzuzo zemvelo.
Ukuze ubone ngeso lengqondo umthelela wamapharamitha abalulekile okwenza umquba esivinini sokuwohloka, ishadi elilandelayo lifingqa izikhathi zokuwohloka ezilinganiselwayo zama-polymer avamile abolayo ngaphansi kwezimo ezahlukahlukene:
| Uhlobo lwe-Polymer | Umquba Wezimboni (55–70°C) | Umquba Wasekhaya (15–30°C) | Indawo yokulahla udoti/Emanzini (5–30°C) |
| I-PLA | Izinyanga ezi-3–6 | >Iminyaka engu-2 | Okungapheli |
| Izingxube Zesitashi | Inyanga e-1–3 | Izinyanga ezingu-6–12 | Kwehliswe kancane kakhulu |
| I-PBAT (Izingxube) | Izinyanga ezi-2–4 | >1 unyaka | Iminyaka kuya emashumini eminyaka |
Leli shadi ligcizelela isidingo sezindawo zomquba eziphathwa kahle kanye nokusekela ukuqapha inqubo ukuze kube neminikelo emihle kakhulu yemvelo kuyo yonke inqubo yokukhiqiza ipulasitiki ebolayo.
Izixazululo: Amasu Okukhiqiza Okuqhubekayo Nokwekhwalithi Ephezulu
Ukukhiqizwa kwepulasitiki ebolayo esebenza kahle, ehambisanayo, futhi ehambisanayo kuncike eziNqubo Zokusebenza Ezijwayelekile (ama-SOP) eziningiliziwe kanye nokuhlolwa okuqhubekayo kwenqubo. Abaphathi bezitshalo kanye nonjiniyela kufanele basungule ama-SOP abhekana ngqo nendlela yokwenza ipulasitiki ebolayo, bagcizelele ukulawula okuqinile kanye nokubhala imibhalo kuzo zonke izigaba. Lokhu kufaka phakathi ukuthathwa kwezinto zokusetshenziswa—okugqamisa ukuzwela okuyingqayizivele komswakama kanye nokuguquguquka kwezitokwe ezisekelwe ku-bio. Ukuqinisekisa ukulandelelwa kwe-lot-to-lot kuvumela izikhungo ukuthi zibone ngokushesha umthombo wokuphambuka futhi zithathe isinyathelo sokulungisa.
Ukuphatha ukusabela kwe-polymerization kubalulekile ngaphakathi kwenqubo yokukhiqiza ipulasitiki ebolayo. Ku-polylactic acid (PLA), lokhu kuvame ukusho ukulawula ngokuqinile izimo ze-polymerization zokuvula indandatho—ukukhethwa kwe-catalyst, izinga lokushisa, i-pH, kanye nesikhathi—ukunciphisa ukwakheka komkhiqizo kanye nokulahlekelwa yisisindo sama-molecule. Ngama-polymer atholakala ekuvuthweni njenge-polyhydroxyalkanoates (PHA), ukuqeda ukungcola ngokusebenzisa izindlela zokuhlanza eziqinile endaweni kanye nokuhlanza okuqinisekisiwe kubalulekile ekuvimbeleni ukulahlekelwa kwesivuno kanye nokwehluleka kwekhwalithi. Imisebenzi kumele yandise amazinga abhalwe phansi ngezigaba zokubumba umjovo wepulasitiki ohlanganisiwe, ophumayo, kanye nowokubola. Amapharamitha enqubo—njengephrofayili yokushisa, isivinini sezikulufo, izikhathi zokuhlala, kanye nokomisa ngaphambi kokucubungula (ngokuvamile amahora angu-2-6 ku-50-80°C)—kumele kugcinwe ngokunembile ukuvimbela ukuwohloka kwe-biopolymer.
Ukuqapha okuqhubekayo kokusebenza kwakha umgogodla wezinqubo zokukhiqiza ipulasitiki zanamuhla, ezinobungani nemvelo. Ukusebenzisa amamitha okuqina angaphakathi—njengalawo ahlinzekwa yiLonnmeter—kanye nama-viscometer aku-inthanethi kwenza izikhungo zikwazi ukuqapha ubuningi be-propylene, ukugcwala kwe-slurry, kanye ne-viscosity ngesikhathi sangempela. Impendulo enjalo esheshayo ivumela ukulungiswa okuqondile kwenqubo, ukuqinisekisa ukuthi ukusabela kwe-polymerization kuhlala ngaphakathi kwemininingwane eqondile. Ukuqapha ubuningi be-propylene ngesikhathi sangempela kubaluleke kakhulu esigabeni sobuningi be-slurry ye-propylene polymerization, ukuvimbela ama-batches angacacisiwe futhi kunciphise ukuphinda kusetshenziswe kanye nokuchitheka kwezinto. Ngokugcina ukulawula okuqinile ngamathuluzi afana nemitha yokuqina kwe-propylene yeLonnmeter, abaqhubi bangaqinisekisa ukuthi ubuningi be-propylene obumanzi buhlala buzinzile kuyo yonke imisebenzi yokukhulisa kanye nomthamo ogcwele. Lokhu akugcini nje ngokuthuthukisa ukuphindaphinda kwenqubo kodwa futhi kuqinisekisa ukuhambisana nezindinganiso zomkhiqizo kanye nezidingo zomthetho.
Idatha evela ekuqapheni okuku-inthanethi ivame ukubonakala njengamashadi okulawula inqubo. Lokhu kungabonisa izinguquko zemizuzu ngemizuzu ezimpahleni ezibalulekile, njengokuthambekela kanye nobuningi, kunikeze isixwayiso esisheshayo sokuphambuka kwemikhuba (bheka uMfanekiso 1). Izenzo zokulungisa ngokushesha zinciphisa ingozi yokukhiqiza izinto ngaphandle kwemininingwane eqondiwe futhi zithuthukise isivuno esiphelele sezinqubo zokukhiqiza ipulasitiki ebolayo.
Ukukhuliswa komkhiqizo ngenkathi kulawulwa izindleko kuletha izinselele ezingapheli zenqubo yokwenza ipulasitiki ebolayo. Izikhungo kufanele zisebenzise izinhlaka zokulawula izindleko eziklanywe ngobuchwepheshe: ukulinganiswa okuvamile kanye namashejuli okugcinwa kwayo yonke imishini yokuqapha, ukuthola izinto eziningi ngokuthembeka komhlinzeki okubhaliwe, kanye nokuhlolwa kwenqubo ekuxubeni okungeziwe (njengoba ezinye izithasiselo zingavimbela ukuwohloka kwe-polymer). Ukuqeqeshwa okuphelele komqhubi kanye nesitifiketi sesikhathi kuzo zonke izinqubo ezibalulekile kusekela ngqo ukuphindaphindeka kuzo zonke izinkathi kanye nokuqhutshwa komkhiqizo. Ukusebenzisa izinto zokubhekisela ezijwayelekile kanye nokuqhathanisa phakathi kwelabhorethri—njengokuhlolwa kwemishini noma izilinganiso zokubolayo—kunezela ungqimba olwengeziwe lokuqiniseka ukuthi inqubo yesayithi elilodwa yokwenza ipulasitiki ebolayo ifana neyomunye.
Izitshalo ezithuthuke kakhulu zibhekisela emikhubeni emihle kakhulu yamazwe ngamazwe—ama-SOP ahlolwe yizo zonke izinyathelo, imibhalo eqinile yochungechunge lokugcinwa, izindlela zokulawula izinqubo zezibalo, kanye nokubuyekezwa okuhlelekile okuhlanganisa okutholakele kwesayensi kwakamuva. Le ndlela ivumela izinqubo zokukhiqiza i-polymer ebolayo esezingeni eliphezulu, ephindaphindwayo, futhi ehambisanayo kunoma yisiphi isikali. Ukulungiswa kobuningi ngokushesha kuyo yonke inqubo yokukhiqiza ipulasitiki kusetshenziswa amamitha angaphakathi kuqinisekisa kokubili ukusebenza kahle kwezindleko kanye nokufana komkhiqizo okuphezulu.
Imibuzo Evame Ukubuzwa (Imibuzo Evame Ukubuzwa)
Iyini inqubo yokwenza i-polymerization yepulasitiki ekukhiqizweni kwepulasitiki ebolayo?
Inqubo yokwenza i-polymerization yepulasitiki ihilela ukusabela kwamakhemikhali okuxhumanisa amayunithi amancane e-monomer—njenge-lactic acid noma i-propylene—kuma-molecule e-polymer anochungechunge olude. Kumapulasitiki abolayo njenge-polylactic acid (PLA), ukwenza i-polymerization ye-lactide evulekayo kuyindinganiso yemboni, kusetshenziswa ama-catalysts afana ne-tin(II) octoate. Le nqubo iphumela kuma-polymer anesisindo esiphezulu sama-molecule anezakhiwo zomzimba ezihlosiwe. Isakhiwo se-polymer kanye nobude beketanga, kokubili okunqunywa ngesikhathi se-polymerization, kuthinta ngqo amandla omshini kanye nesilinganiso sokubola kwe-bio. Ezinhlelweni ezisekelwe ku-propylene, i-catalysis ye-Ziegler-Natta iguqula ama-monomer e-propylene abe amaketanga e-polypropylene. Lapho kukhiqiza izinhlobo ezibolayo, abacwaningi bangase bahlanganise i-propylene ngama-comonomer abolayo noma bashintshe umgogodla we-polymer ngamaqembu abolayo ukuze kuthuthukiswe amazinga okuwohloka kwemvelo.
Uyenza kanjani ipulasitiki ebolayo?
Ipulasitiki ebolayo yenziwa ngokuthola izinto zokusetshenziswa ezivuselelekayo njengomoba noma ummbila, zivundise zibe ama-monomers njenge-lactic acid, bese zi-polymer zibe ama-polymer afana ne-PLA. Ama-polymer aphumayo ahlanganiswa nezithasiselo ezisebenzayo ukuthuthukisa ukucutshungulwa nokusebenza. Lezi zingxube zicutshungulwa ngamasu okubumba njengokubunjwa komjovo noma ukukhipha ukuze kwakhiwe imikhiqizo yokugcina. Amapharamitha enqubo alawulwa ngokuqinile kulo lonke isigaba ngasinye ukuqinisekisa ubuqotho bento kanye nokubola kokusetshenziswa kokugcina. Isibonelo ukupakishwa kokudla okusekelwe ku-PLA, okuqala kusuka kusitashi sezitshalo bese kuphela njenge-wrappers e-compostable eqinisekiswe ngaphansi kwezindinganiso ezifana ne-EN 13432.
Yiziphi izinto ezibalulekile okufanele uzicabangele ekubunjweni kwepulasitiki ebolayo?
Ukufakwa ngempumelelo kwepulasitiki ebolayo kuncike ekuphathweni okunembile kwezinga lokushisa, njengoba ukushisa ngokweqile kuholela ekuwohlokeni kwangaphambi kwesikhathi kanye nokwehla kwamandla omkhiqizo. Ukulawulwa komswakama okufanele kubalulekile ngoba ama-polymer abolayo avame ukumanzisa ezimweni ezimanzi, okuthinta isisindo sama-molecule kanye nezakhiwo zomzimba. Izikhathi zomjikelezo ezilungiselelwe ziyadingeka ukuqinisekisa ukugcwaliswa okuphelele ngenkathi kugwenywa ukuvezwa isikhathi eside kokushisa. Ukwakheka kwesikhunta kungahluka kumapulasitiki avamile ngenxa yokugeleza okuhlukile kanye nezici zokupholisa zama-resin abolayo. Isibonelo, izikhathi zokuhlala ezimfushane kanye namazinga aphansi okusika kungagcina ikhwalithi ye-polymer futhi kunciphise imfucuza.
Ukuqapha ubuningi be-propylene ku-inthanethi kusiza kanjani enqubweni yokukhiqizwa kwepulasitiki ebolayo?
Izinhlelo zokulinganisa zesikhathi sangempela, njengemitha yobuningi be-propylene e-inline evela eLonnmeter, zinikeza impendulo esheshayo ngobuningi be-propylene ngaphakathi kwe-reactor ye-polymerization. Lokhu kuqinisekisa ukuthi inqubo ye-polymerization ihlala ngaphakathi kwamapharamitha okuqondiwe, okuvumela opharetha ukuthi balungise izimo ngokushesha. Ubuningi be-propylene obuzinzile busekela ukukhula kwe-polymer chain okuqhubekayo kanye nokwakheka kwama-molecule okulungile, kunciphisa ukuguquguquka kwezinto futhi kuthuthukise isivuno somkhiqizo jikelele. Lokhu kubalulekile lapho kukhiqizwa izinhlobo ze-polypropylene ezibolayo, lapho ukulawulwa kwenqubo kuthinta ngqo zombili izakhiwo zemishini kanye nokubola okuqondiwe.
Kungani ubuningi be-slurry bubalulekile enqubweni yokwenza i-propylene polymerization?
Ubuningi be-propylene slurry—ingxube ye-catalyst emisiwe, i-monomer, kanye ne-polymer eyakhayo—ithinta ukudluliselwa kokushisa, amazinga okusabela, kanye nokusebenza kahle kwe-catalyst. Ukugcina ubuningi be-slurry obufanele kuvimbela izindawo ezishisayo, kunciphisa ingozi yokungcola kwe-reactor, futhi kuvumela ukukhula kwe-polymer okufanayo. Ukuguquguquka kobuningi be-slurry kungaletha amaphutha nezinto ezibonakalayo kanye nokwehluka ekusebenzeni komshini kokugcina kwe-resin kanye nephrofayili yokubola. Ngakho-ke ukulawulwa okuqinile kobuningi be-slurry kubalulekile ukuze inqubo izinze kanye nekhwalithi yokukhiqiza eqhubekayo ekukhiqizweni kwepulasitiki ebolayo.
Yimaphi amathuluzi asetshenziswayo ekulinganisweni kwesikhathi sangempela kobuningi be-propylene yoketshezi?
Amamitha okuqina angaphakathi, njengalawo akhiqizwe yiLonnmeter, asetshenziselwa ukuqapha ukuqina kwe-propylene ewuketshezi ngqo emigqeni yokukhiqiza. Lawa mamitha asebenza ngaphansi kwezimo zenqubo ezidingayo, elinganisa ukuqina okuqhubekayo futhi edlulisela idatha yokulawulwa kwesitshalo ngokushesha. Ukufundwa okunembile, kwesikhathi sangempela kuvumela ithimba lokukhiqiza ukuthi libone ukuphambuka ngokushesha, lisekele ukulungiswa okusebenzayo ezimweni ze-reactor. Lokhu kuphumela ekulawulweni kwe-polymerization okuthuthukisiwe, ukuhambisana okungcono kwe-batch, kanye nokuxazulula izinkinga okusebenzayo—okubalulekile kokubili kumaphrojekthi okuhlola kanye nezinqubo zokukhiqiza ipulasitiki ebolayo esezingeni lokuhweba.
Isikhathi sokuthunyelwe: Disemba 18-2025
