Nylon 66 ntsev, uas raug hu ua hexamethylenediammonium adipate, yog cov khoom sib npaug ntawm hexamethylenediamine (HMDA) thiab adipic acid. Nws yog tus ua ntej rau nylon 66 polymer, uas tswj hwm cov yas engineering vim nws lub zog siab thiab thermal stability. Cov ntsev no, pom tias yog cov khoom sib xyaw crystalline ionic hauv cov kua dej, qhia txog cov khoom tshwj xeeb tseem ceeb rau cov txheej txheem polycondensation downstream uas ua rau nylon 66 fibers thiab resins. Cov qauv molecular muaj cov ammonium moieties zoo los ntawm HMDA thiab cov carboxylate pawg tsis zoo los ntawm adipic acid, tsim cov ionic lattices lossis, thaum yaj, cov ions sib cais npaj rau polymerization.
Qhov kev ua kom huv thiab kev huv ntawm cov qauv no cuam tshuam ncaj qha rau qhov hnyav molecular ntawm cov polymer, crystallinity, thiab thermal profile. Kev tshawb fawb hauv chaw kuaj mob thiab kev lag luam lees paub qhov sib piv ionic 1: 1 siv cov txheej txheem spectroscopic thiab X-ray diffraction, ua kom qhov stoichiometry no tseem ceeb rau kev ua haujlwm zoo ntawm cov khoom kawg. Txawm tias qhov kev hloov pauv me me tuaj yeem cuam tshuam kev sib npaug ntawm cov saw hlau, ua rau cov khoom siv kho tshuab tsis zoo.
Kev Npaj Ntsev Nylon 66
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Hexamethylenediamine, nrog nws cov qauv H2N-(CH2)6-NH2 linear, ua haujlwm ua cov khoom diamine xa cov pawg amine kawg rau kev tsim ntsev. Adipic acid, HOOC-(CH2)4-COOH, ua kom tiav qhov no nrog cov haujlwm carboxyl reactive. Lawv qhov kev ua haujlwm zoo thiab kev dawb huv siab yog qhov txiav txim siab: HMDA feem ntau yog distilled lossis crystallized kom tshem tawm cov oligomeric thiab cov organic traces, thaum adipic acid dhau los ntawm recrystallization, filtration, thiab qee zaum ion-exchange kom ntseeg tau tias tshem tawm cov xim, organics, thiab cov hlau contaminations. Purity saum toj no 99.5% yog tsom rau kev lag luam; txawm tias cov kab mob me me tuaj yeem ua rau cov polymer zoo dua, discolor cov khoom tiav, lossis cov tshuaj lom catalysts hauv cov tshuaj tiv thaiv ntxiv.
Lub hauv paus ntawm kev tsim cov ntsev nylon 66 yog qhov yooj yim tab sis tswj tau nruj me ntsis. Hauv cov kua dej, HMDA txais cov protons los ntawm cov pab pawg carboxyl ntawm adipic acid, tsim cov ammonium ions thaum tib lub sijhawm tsim cov carboxylates. Qhov kev sib cuam tshuam ntawm cov kua qaub-base no tau ua tib zoo npaj:
H2N-(CH2)6-NH2 + HOOC-(CH2)4-COOH → [H2N-(CH2)6-NH3+][OOC-(CH2)4-COO−] (ntsev nylon, dej)
Nyob rau hauv kev siv tshuab, kev sib cuag thawj zaug tso cai rau diamine kom protonate ib nrab, tsim ib qho zwitterionic intermediate. Kev ua tiav nyob ntawm kev hloov pauv proton tag nrho thiab neutralization. pH yog tsim los kom ncav cuag neutrality - ze rau 7 - ua lub cim ntawm cov kua qaub-base sib npaug. Qhov kub zoo tshaj plaws ua rau ob qho tib si reaction kinetics thiab tom qab ntawd ntsev crystallization; hauv kev xyaum, qhov kub ntawm 25 ° C txog 100 ° C yog siv. Txawm li cas los xij, qhov kub siab hauv pH lossis kub tuaj yeem ua rau qeeb qhov reaction lossis cov khoom by-products: acidic lossis basic mob ua rau tsis tiav ntsev tsim thiab tuaj yeem hloov pauv solubility thiab crystal daim ntawv. Kev lees paub zoo niaj hnub no siv cov pH hauv kab thiab kev ntsuas conductivity, feem ntau saib xyuas tas li, kom lav qhov stoichiometry raug thiab tiv thaiv cov txheej txheem tu siab.
Qhov ntau dhau los yog qhov tsis txaus hauv ib qho reactant ua rau cov pab pawg kawg ua haujlwm hauv cov ntsev thiab, los ntawm kev nthuav dav, hauv nylon polymer. Qhov no cuam tshuam rau qhov ntev ntawm cov saw hlau, polydispersity, thiab cov yam ntxwv tensile. Kev sib raug zoo ntawm qhov ceev ntawm cov kua ntsev thiab kev tswj cov txheej txheem tau hais txog hauv kev xyaum ua haujlwm niaj hnub no, qhov twgkev ntsuas qhov ceev ntawm cov kua dej tiag tiagthiab kev ntsuas qhov ceev ntawm cov kua dej yog qhov tseem ceeb rau cov txheej txheem npaj ntsev nylon 66. Kev saib xyuas qhov ceev kom zoo tsis yog tsuas yog ua kom muaj kev sib npaug ntawm cov khoom sib xyaw xwb tab sis kuj pab txhawb kev tswj cov ntsev uas saturated piv rau cov ntsev uas supersaturated uas xav tau rau kev polymerization lossis khaws cia tom qab.
Hauv kev xaus, qhov kev sib koom ua ke ntawm cov tshuaj lom neeg ntawm kev ua kom tsis muaj zog, kev tswj hwm pH thiab kub, thiab qhov huv si ntawm HMDA thiab adipic acid yog lub hauv paus ntawm cov txheej txheem tsim cov ntsev nylon 66 uas ua tiav. Nws yog qhov kev ua kom raug no uas tswj hwm qhov zoo ntawm tag nrho cov txheej txheem tsim cov nylon 66 polymer thiab, thaum kawg, cov khoom siv hauv kev lag luam thoob plaws hauv tsheb, textile, thiab cov kab khoom hluav taws xob.
Cov Kauj Ruam Ua Ntej Nylon 66 Cov Txheej Txheem Ua Ntsev
Cov txheej txheem npaj ntsev nylon 66 pib nrog kev npaj cov kua dej sib cais ntawm adipic acid thiab hexamethylenediamine, ob lub monomers tseem ceeb rau kev tsim ntsev nylon 66. Adipic acid raug yaj rau hauv dej deionized, feem ntau ntawm 30–60 ° C, kom txog thaum cov kua ntshiab tsim. Hexamethylenediamine ua raws li cov txheej txheem tib yam, ua rau cov kua nplua nuj amine. Ob qho kev daws teeb meem raug lim kom zoo kom tshem tawm cov khoom me me ua ntej kev cuam tshuam ntxiv, txhawb kev ntsuas qhov ceev ntawm cov kua ntsev rau kev tswj hwm qhov sib piv thiab cov txheej txheem zoo tshaj plaws.
Kev tswj hwm, kev sib tov uas tswj tau qhov kub thiab txias yog qhov tseem ceeb rau kev ua tiav qhov sib piv stoichiometric 1: 1 molar, vim tias txawm tias qhov sib txawv me me kuj cuam tshuam rau kev ua haujlwm ntawm polymerization thiab cov khoom siv resin. Ob qho kev daws teeb meem no tau maj mam nkag mus rau hauv lub tshuab hluav taws xob uas muaj kev sib xyaw zoo, uas ua rau kev tswj hwm qhov nrawm ntawm kev sib tov zoo. Kev tswj hwm qhov kub thiab txias kom raug tiv thaiv kev kub hnyiab hauv zos, kev ua kom crystallization ua ntej lub sijhawm, lossis kev ua kom hydrolysis tsis xav tau, ua kom muaj ib puag ncig ntawm cov tshuaj tiv thaiv ntsev nylon 66 sib xws.
Thoob plaws hauv kev sib tov thiab kev ua kom tsis muaj zog hauv nylon 66, ib daim pam roj inert, feem ntau yog nitrogen, raug tswj hwm hauv lub thawv. Qhov kev tiv thaiv huab cua inert no yog qhov tseem ceeb rau kev tshem tawm cov pa oxygen thiab carbon dioxide hauv huab cua, uas tuaj yeem ua rau oxidation lossis ua rau muaj cov khoom tsis huv carbonate / bicarbonate, ua rau cov ntsev tsis zoo. Cov roj inert kuj tseem ua rau cov khoom sib xws thiab kev ruaj khov ntawm kev khaws cia, qhov tseem ceeb rau cov ntawv thov siab.
Thaum kev sib xyaw ua ke tswj tau mus ntxiv, cov hom nruab nrab nrog cov carboxyl lossis amine xaus yuav tsim, nyob ntawm seb lub zos stoichiometry thiab qhov sib xyaw npaum li cas. Kev ua kom tiav tag nrho ua rau cov ntsev nylon 66 xav tau (tseem hu ua AH ntsev), uas muaj cov stoichiometry thiab molecular uniformity uas tau teev tseg. Cov tshuaj tiv thaiv neutralization ua raws li cov ntsiab cai ntawm acid-base chemistry, thiab mus txog pH ze rau neutrality (pH 7–7.3) yog qhov yuav tsum tau ua rau cov polymerization downstream sib xws, vim tias cov acid lossis base pawg ntau dhau cuam tshuam rau kev loj hlob ntawm cov saw hlau thiab cuam tshuam rau qhov hnyav molecular thiab qhov zoo ntawm polymer kawg.
Kev saib xyuas pH thiab kev titration tiag tiag ua rau muaj kev tawm tswv yim nruj thaum lub sijhawmkev ua kom tsis muaj zog, xyuas kom meej tias qhov sib xyaw ua ke thiab cov nqi tau zoo tshaj plaws kom tsis txhob muaj kev cuam tshuam hauv zos lossis tsis muaj kev cuam tshuam. Cov qauv kinetic niaj hnub no lees paub tias txawm tias qhov tsis sib npaug me me hauv stoichiometry ntsuas tau tias kev ua haujlwm polymerization tsis zoo.
Tom qab tsim cov ntsev tsis muaj ntsev, cov txheej txheem no nce mus txog theem kev ntxuav kom lav tau cov khoom muaj txiaj ntsig zoo. Cov tswv yim lim dej ntau kauj ruam—txij li cov lim dej loj mus rau cov lim dej submicron—tshem tawm cov hlau ions, cov khoom me me, thiab cov organic residues uas tau los ntawm cov khoom siv raw lossis cov dej ua. Kev kho ion-pauv ua raws li, rho tawm cov khoom tsis huv uas yaj tau xws li sulfate, calcium, lossis sodium ions uas ua rau cov ntsev nylon 66 tsis zoo. Tom qab ntawd cov khoom sib xyaw ua ke thiab raug tswj hwm crystallization, tsim cov ntsev crystals ntshiab nrog kev pom tseeb thiab cov xim lossis pos huab uas tsis pom.
Kev tswj xyuas zoo yog sib xyaw ua ke rau hauv cov txheej txheem npaj ntsev rau kev siv hauv kev lag luam, nrog rau kev saib xyuas tas li ntawm UV absorbance thiab optical purity ntawm txhua theem. Tus ntsuas UV qis yog qhov tseem ceeb - tus ntsuas siab qhia txog qhov muaj cov chromophoric impurities, uas yuav ua rau cov khoom nylon 66 polymer kawg tsis muaj xim thiab ua rau muaj qhov tsis zoo hauv cov fibers lossis cov khoom pwm. Rau cov txheej txheem polymerization muaj nqis siab, kev kuaj xyuas pom thiab spectroscopic ua kom ntseeg tau tias muaj ntsev tsis muaj xim, optically pure, tiv thaiv kev daj thiab kev tsis sib xws ntawm cov khoom siv.
Kev soj ntsuam qhov ceev hauv cov txheej txheem tshuaj lom neeg, tshwj xeeb yog siv cov txheej txheem ntsuas qhov ceev ntawm cov kua thiab cov ntsuas qhov ceev hauv kab xws li cov uas tsim los ntawm Lonnmeter, ntxiv ib qho kev tiv thaiv ntxiv. Cov cuab yeej no lees paub qhov kev sib xyaw kawg ntawm cov kua ntsev, txhawb nqa cov txheej txheem rov ua dua. Kev ntsuas qhov ceev ntawm cov kua kom raug yog qhov tseem ceeb rau kev ntes cov kev hloov pauv me me hauv cov khoom khov, uas cuam tshuam ncaj qha rau kev siv crystallization thiab cov kauj ruam polymerization tom qab.
Kev koom ua ke ntawm kev ua kom huv si thiab kev tswj xyuas zoo hauv cov txheej txheem ua ntsev nylon 66 ua rau muaj kev ua tau zoo thiab kev ua tau zoo ntawm polymer. Kev saib xyuas kev tshuaj xyuas kom meej, txij li UV index mus rau pH thiab qhov ceev, ua rau muaj kev tsim cov ntsev uas muaj kev ntshiab siab, pom tseeb, thiab sib npaug zoo rau cov ntawv thov polymer hauv kev lag luam.
Kev Tsim Ntxwv Nylon 66 Rau Kev Lag Luam: Kev Ntsuas thiab Kev Txhim Kho Cov Txheej Txheem
Kev Tsim Ntshav Ntawm Qhov Ntsuas Kev Lag Luam
Cov txheej txheem npaj ntsev nylon 66 rau kev lag luam yog tsom mus rau qhov kev ua kom tsis muaj zog ntawm adipic acid thiab hexamethylenediamine. Kev nthuav dav los ntawm chav kuaj mus rau cov chaw ua haujlwm cog qoob loo suav nrog kev hloov pauv kev ua kom tsis muaj zog ntau ntau mus rau hauv cov txheej txheem txuas ntxiv mus, qhov twg cov tshuaj reactants sib xyaw ua ke hauv qab kev tswj hwm zoo kom tau txais hexamethylenediammonium adipate - tseem hu ua ntsev nylon.
Hauv kev tsim cov ntsev nylon 66 loj, qhov zoo ntawm cov khoom siv raw yog qhov tseem ceeb heev. Kev hloov pauv ntawm adipic acid lossis hexamethylenediamine purity cuam tshuam ncaj qha rau stoichiometry, ua rau cov khoom tsis raws li qhov xav tau yog tias tsis tswj hwm. Cov txheej txheem pub mis yuav tsum ua kom muaj kev noj tshuaj ruaj khov, them rau kev hloov pauv ntawm cov khoom siv raw thiab qhov kub.
Kev sib xyaw ua ke yog lwm lub hauv paus tseem ceeb. Cov reactors kev lag luam vam khom kev sib xyaw ua ke siab kom tsis txhob muaj kev sib xyaw ua ke uas ua rau tsis muaj kev cuam tshuam. Kev sib xyaw tsis zoo ua rau muaj cov kua qaub lossis amine tsis muaj zog, tsim cov ntsev nrog pH tsis ruaj khov thiab cov ntsiab lus yaj sib txawv. Cov nroj tsuag niaj hnub no siv cov reactors sib xyaw ua ke (CSTRs) rau lawv cov kev sib xyaw zoo dua thiab cov khoom tsim tawm zoo sib xws, tshwj xeeb tshaj yog thaum cuam tshuam nrog cov khoom siv raw hloov pauv lossis thaum xav tau stoichiometry meej. Rau cov tshuaj yooj yim dua thiab qhov twg linear flow nyiam, plug flow reactors (PFRs) muab kev faib tawm lub sijhawm nyob nruj dua thiab qis dua qhov kub hauv zos, tab sis tsis muaj peev xwm sib xyaw tag nrho ntawm CSTRs.
Kev tswj qhov kub thiab txias ua rau cov txheej txheem ruaj khov. Kev ua kom tsis muaj cua sov yuav tsum tau siv cov thawv uas muaj lub tsho lossis cov khoom sib pauv cua sov kom tswj tau qhov kub thiab txias zoo tshaj plaws - feem ntau yuav tsum nyob ze li ntawm 210 ° C. Kev hloov pauv siab dua lossis qis dua qhov no ua rau hydrolysis lossis crystallization tsis zoo ntawm cov ntsev, raws li, cuam tshuam rau kev ua polymerization hauv qab.
Cov Kab Khoom Siv thiab Khoom Siv Hauv Kev Lag Luam
Cov khoom siv tshuaj tiv thaiv ntsev nylon 66 loj yog tus cwj pwm los ntawm nws txoj kev tsim kho ruaj khov thiab kev koom ua ke ntawm cov thev naus laus zis tswj hwm meej. Kev xaiv cov reactor feem ntau yog nyob nruab nrab ntawm CSTRs, nyiam rau lawv qhov kev sib xyaw ua haujlwm zoo thiab kev sib npaug ntawm cov khoom, thiab PFRs, uas pab txhawb kev ntws mus tas li qhov twg kev sib xyaw ua ke tsis tseem ceeb.
Cov tshuab sib tov hauv kev lag luam yog tsim los rau kev sib tov sai thiab tag nrho ntawm cov kua qaub thiab diamine. Cov impellers siab-shear thiab cov voj voog rov ua dua faib cov tshuaj reactants sib npaug txawm tias muaj ntau qhov hloov pauv lossis viscosity, txo qhov kev pheej hmoo ntawm cov chaw kub thiab tsis tiav.
Cov txheej txheem saib xyuas cov txheej txheem hauv kab yog qhov tseem ceeb rau kev tswj hwm thiab sau txhua theem. Cov ntsuas pH hauv kab, cov ntsuas kub, thiab cov ntsuas ceev ceev hauv kab (xws li cov uas tsim los ntawm Lonnmeter) yog qhov tseem ceeb rau kev teeb tsa niaj hnub. Kev ntsuas qhov ceev ntawm cov kua dej tiag tiag ua rau cov neeg ua haujlwm tuaj yeem ua kom muaj cov ntsev thiab cov khoom sib xyaw kom raug thoob plaws hauv cov txheej txheem. Cov kev daws teeb meem saib xyuas qhov ceev no muab cov lus tawm tswv yim uas tso cai rau kev hloov kho cov nqi pub thiab qhov kub kom tswj tau qhov zoo ntawm cov ntsev. Kev ntsuas qhov ceev ntawm cov kua dej niaj hnub yog ua tiav los ntawm kev siv cov tshuaj ntsev zoo kom ntseeg tau tias cov ntaub ntawv raug raws li cov xwm txheej hloov pauv.
Cov txheej txheem kev nyab xeeb yog qhov yuav tsum tau ua vim yog qhov xwm txheej ntawm nylon 66 ntsev uas ua rau xeb thiab hygroscopic. Cov thoob dej cia khoom yog tsim los ntawm cov hlau tsis xeb, muaj cov txheej txheem npog uas tiv thaiv kev nqus dej noo thiab kev ua qias tuaj. Cov kav dej thauj khoom kaw, cov txheej txheem thauj khoom tsis siv neeg, thiab cov yam ntxwv tswj kev nchuav tag nrho pab txo qhov kev phom sij ntawm ib puag ncig thiab cov neeg ua haujlwm hauv kev khaws cia thiab hloov cov ntsev.
Kev Txhim Kho Cov Txheej Txheem rau Kev Sib Xws ntawm Cov Khoom
Kev tswj cov khoom kom sib xws hauv kev tsim cov ntsev nylon 66 yuav tsum tau kho kom raug ntawm cov txheej txheem. Lub hom phiaj viscosity - ib qho tseem ceeb rau cov khoom nylon 66 polymer kawg - nyob ntawm kev tswj hwm nruj ntawm cov xwm txheej tshuaj tiv thaiv thaum lub sijhawm tsim ntsev thiab nws cov polymerization tom qab.
Kub yog tswj ntawm kwv yees li 210 ° C nrog kev kam rau siab, raws li kev hloov pauv hloov qib ntawm neutralization thiab ntsev solubility. Kev tswj siab, feem ntau teeb tsa ze li ntawm 1.8 MPa hauv cov kauj ruam ua ntej-polycondensation, ua kom muaj tus cwj pwm theem raug thiab kinetics tshuaj tiv thaiv. Lub sijhawm nyob hauv reactors yog calibrated kom tso cai rau kev hloov pauv tag nrho, thaum zam kev raug cua sov ntau dhau uas tuaj yeem ua rau cov khoom puas tsuaj. Qhov kev ua kom sib npaug no yog txhim kho ntxiv siv cov ntaub ntawv los ntawm inline viscosity thiab density meters.
Kev xaiv cov tshuaj catalyst thiab cov koob tshuaj muaj feem cuam tshuam rau theem polymerization ntawm nylon 66, uas ua raws li kev tsim ntsev. Cov koob tshuaj catalyst feem ntau yog li ntawm 0.1 wt% los ua kom qhov hnyav molecular zoo dua thiab txhawb kev loj hlob ntawm cov saw polymer. Kev noj ntau dhau tuaj yeem ua rau cov tshuaj tiv thaiv sai dua tab sis muaj kev pheej hmoo ntawm kev tawg lossis kev tsim xim tsis raug tswj; kev noj tsawg dhau ua rau kev sib xyaw thiab cov khoom siv kho tshuab cuam tshuam. Kev ntsuas kom raug thiab kev sib xyaw sai ntawm cov tshuaj catalyst, feem ntau nyob hauv cov tshuaj nrog cov ntsev pub, ua rau kev ua haujlwm zoo dua.
Txhua yam ntawm cov kev ntsuas no raug kho kom zoo raws li lub sijhawm tiag tiag raws li cov ntaub ntawv zoo. Piv txwv li, yog tias kev saib xyuas qhov ceev hauv kab qhia txog kev hloov pauv qhia txog kev ua kom tsis muaj zog ntau dhau lossis tsis txaus, cov nqi pub reactant raug hloov kho raws li qhov ntawd. Lub voj voog tawm tswv yim no tseem ceeb heev rau kev tiv thaiv cov ntsev tsis sib xws, uas tom qab ntawd yuav ua rau muaj kev phom sij rau cov polymer viscosity thiab kev ua haujlwm kawg.
Qhov Ceev ntawm Cov Tshuaj Ntshav: Kev Saib Xyuas thiab Kev Ntsuas Cov Tswv Yim
Qhov Tseem Ceeb ntawm Kev Saib Xyuas Qhov Ceev hauv Kev Npaj Ntsev
Thaum lub sijhawm ua cov txheej txheem ua ntsev nylon 66, kev saib xyuas qhov ceev yog qhov tseem ceeb heev. Qhov kev sib xyaw ua ke ntawm hexamethylenediamine thiab adipic acid tsim cov ntsev uas nws qhov huv thiab kev haum rau cov txheej txheem tsim cov polymer nylon 66 tau pom tseeb los ntawm qhov ceev ntawm cov tshuaj. Kev ntsuas qhov ceev qhia tau qhov concentration ntawm reactant, qhia txog qhov sib npaug ntawm acid thiab amine, thiab ua haujlwm ua tus sawv cev rau kev ua tiav kev hloov pauv thiab cov dej hauv cov txheej txheem.
Kev tswj kom qhov ceev ntawm cov ntsev kom zoo tshaj plaws yog qhov tseem ceeb heev. Kev hloov me ntsis tuaj yeem ua rau pom qhov tsis zoo ntawm stoichiometry, xws li cov kua qaub lossis amine ntau dhau, uas ua rau kev ua haujlwm polymerization tsis zoo, cuam tshuam rau kev faib tawm qhov hnyav molecular, thiab ua rau cov khoom kawg tsis zoo. Piv txwv li, hauv kev siv tshuaj rov ua dua tshiab, kev hloov pauv ntawm qhov ceev ntawm cov kua thaum lub sijhawm hydrolysis uas muaj acid-catalyzed hloov pauv hydrogen bonding hauv polymer, uas cuam tshuam rau qhov nkag mus rau enzyme thiab cov nqi rov qab monomer. Kev tswj qhov ceev tsis txaus ntawm theem no ua rau kev hloov pauv tsis tiav lossis pov tseg, cuam tshuam ncaj qha rau cov nroj tsuag cov qoob loo thiab kev ntsuas kev ruaj khov.
Cov ntaub ntawv los ntawm cov kab khoom siv tshuaj lom neeg hauv kev lag luam qhia tias kev saib xyuas qhov ceev ntawm cov khoom siv tsis siv neeg yog qhov tseem ceeb rau kev tsim cov ntsev uas huv si thiab ruaj khov, tib lub sijhawm txo cov khib nyiab, ua kom zoo dua qhov ua tiav, thiab xyuas kom ua raws li cov kev cai ntawm cov txheej txheem. Qhov no tau dhau los ua qhov tseem ceeb thaum muaj kev nyuaj siab ntawm kev tswj hwm thiab kev ruaj khov, xav tau kev tswj hwm cov txheej txheem nruj dua thiab kev ua haujlwm zoo dua.
Cov Txheej Txheem Ntsuas Qhov Ceev ntawm Cov Kua
Keeb kwm los, cov txheej txheem xws li pycnometry lossis hydrometers ntsuas qhov ceev ntawm cov kua ntsev tab sis raug kev txom nyem los ntawm kev ua haujlwm tsis raug thiab kev cuam tshuam tes, ua rau lawv tsis haum rau kev saib xyuas kev lag luam tas mus li. Kev xyaum ua lag luam niaj hnub no nyiam siv cov cuab yeej ua haujlwm tsis siv neeg, muaj qhov tseeb heev.
Cov ntsuas qhov ceev ntawm cov raj U-tube uas txav tau zoo yog tus qauv kev lag luam rau kev ntsuas qhov ceev ntawm cov kua ntsev. Lub hauv paus ntsiab lus yog yooj yim: lub raj zoo li tus U, uas muaj cov kua ntsev puv, txav ntawm qhov zaus uas hloov pauv nrog kev hloov pauv ntawm qhov ceev ntawm cov kua. Vim tias cov kua ntau dua ua rau lub raj txav qeeb dua, cov khoom siv hluav taws xob rhiab heev ntsuas qhov kev hloov pauv zaus no thiab hloov nws mus rau qhov nyeem qhov ceev ncaj qha.
Kev xaiv cov khoom siv raj, xws li hlau tsis xeb lossis cov hlau sib xyaw tshwj xeeb, yog coj los ntawm kev sib haum xeeb ntawm cov tshuaj nrog cov kua ntsev. Cov 'meter' no ua haujlwm tau zoo ntawm cov kab ntau lawm thiab xa cov txiaj ntsig sai, rov ua dua, ua rau lawv zoo rau qhov chaw tsim khoom ntsev nylon 66.
Lonnmeter tshwj xeeb hauv kev ntsuas qhov ceev hauv kab uas ruaj khov uas tsim los rau kev teeb tsa hauv kev lag luam hnyav, ua kom ntseeg tau tias kev ua haujlwm ruaj khov thiab kev ntsuas rov ua dua txawm tias nyob hauv cov chaw muaj tshuaj lom neeg hnyav. Cov ntsuas qhov ceev hauv kab xa mus ncaj qha rau ntawm cov kav dej ua haujlwm, tso cai rau kev saib xyuas lub sijhawm tiag tiag ntawm cov ntsev thaum lub sijhawm ua haujlwm ntau thiab cov txheej txheem txuas ntxiv uas cuam tshuam nrog kev npaj ntsev nylon 66.
Kev kho kom raug ntawm cov ntsuas no yog qhov tseem ceeb rau kev nyeem tau qhov tseeb. Kev kho kom raug suav nrog cov tshuaj txheem ntawm cov qhov ceev uas tau teev tseg los teeb tsa cov ntsiab lus siv ua ntej siv cov cuab yeej nrog cov kua dej ua haujlwm. Qhov no ua kom ntseeg tau tias cov nqi ntsuas tau qhia txog qhov tseeb ntawm cov ntsev - tseem ceeb rau kev ua kom cov xwm txheej teb nyob hauv qhov kev kam rau siab.
Kev Sib Koom Ua Ke Cov Ntaub Ntawv Ceev rau Kev Tswj Xyuas Txheej Txheem
Kev koom ua ke ntawm kev ntsuas qhov ceev tiag tiag rau hauv kev tswj cov txheej txheem tsis siv neeg ua rau kev ua haujlwm zoo dua hauv kev tsim cov ntsev nylon 66. Los ntawm kev muab cov ntsuas qhov ceev hauv kab ncaj qha rau hauv cov txheej txheem tsim khoom, cov ntaub ntawv qhov ceev tau raug ntes tas li thiab pub rau lub kaw lus tswj.
Cov txheej txheem tsis siv neeg piv cov nyeem ntawv ceev nrog cov nqi zoo tshaj plaws rau cov kua ntsev. Thaum pom qhov sib txawv, lub kaw lus tuaj yeem ua qhov kev hloov kho tam sim ntawd - xws li hloov cov dej ntws, kho cov dej hauv, lossis hloov cov ntsiab lus kub - kom tsav cov txheej txheem rov qab mus rau hauv qhov kev qhia tshwj xeeb yam tsis muaj kev cuam tshuam los ntawm tus neeg teb xov tooj.
Txoj kev no tiv thaiv kev hloov pauv ntawm ib pawg mus rau ib pawg, muab lub voj voog rov qab kaw uas hais txog kev hloov pauv ntawm cov txheej txheem, kev nqus dej tsis tau xav txog, lossis kev ua kom tsis tiav hauv lub sijhawm tiag tiag. Nws yog qhov tseem ceeb rau kev ua kom zoo dua cov xwm txheej polymerization uas ua raws li kev npaj ntsev. Piv txwv li, qhov ceev ntawm cov kua ntsev sib xws sib raug zoo nrog qhov hnyav molecular polymer thiab viscosity uas kwv yees tau, txhawb nqa qhov kev ruaj khov thiab thermal siab uas xav tau rau cov khoom nylon 66 tsim.
Piv txwv los ntawm cov haujlwm lag luam tseem ceeb qhia tias kev sib koom ua kekev nyeem ntawv ceev hauv onlinenrog rau cov kev ntsuas ib txwm muaj—xws li qhov kub thiab pH—ua rau muaj ntau yam txheej txheem ua kom zoo dua. Qhov tshwm sim yog qhov sib npaug ntawm cov khoom siv ntau dua, txo cov khoom tsis raws li qhov tau teev tseg, thiab txo qis zog thiab cov khoom siv thaum lub sijhawm ua cov tshuaj nylon 66 ntsev. Kev koom ua ke no tam sim no suav hais tias yog kev coj ua zoo tshaj plaws rau kev lag luam tshuaj lom neeg, ua haujlwm rau ob qho tib si kev lees paub zoo thiab kev ruaj khov hauv cov kab tsim khoom polymer niaj hnub no.
Los ntawm Ntshav mus rau Nylon 66 Polymer: Polycondensation thiab Post-Processing
Kev tswj cov qauv molecular thiab cov yam ntxwv ntawm nylon 66 xav tau kev tswj hwm meej ntawm ntau yam txheej txheem thaum lub sijhawm ua ntej-polycondensation, yaj polycondensation, thiab tom qab ua tiav. Txhua theem—txij li thaum pib tsim cov kua ntsev mus txog rau qhov kawg pellet zoo—ua lub luag haujlwm tseem ceeb hauv kev tsim cov nylon 66 resin qib kev lag luam.
Cov Txheej Txheem Ua Ntej Polycondensation
Cov kauj ruam polycondensation, qhov twg nylon 66 tsim los ntawm kev sib xyaw ntawm adipic acid nrog hexamethylenediamine, yog qhov rhiab heev rau cov kev hloov pauv ua haujlwm. Kub, siab, thiab lub sijhawm teb yog cov yam tseem ceeb tshaj plaws ntawm qhov hnyav molecular thiab intrinsic viscosity. Kev lag luam polycondensation ua haujlwm ntawm 280 ° C thiab 300 ° C. Kub ntawm qhov kawg sab saud ntawm qhov ntau no, ua ke nrog lub sijhawm teb ntev, ua rau muaj kev pheej hmoo ntawm kev puas tsuaj thermal, qhia cov khoom by-products thiab txo qis kev ruaj khov polymer ntev. Txhawm rau kom ua kom qhov hnyav molecular siab tshaj plaws thiab tswj hwm qhov faib tawm qhov hnyav molecular nqaim, qhov poob siab ib ntus tau qhia kom nrawm tshem tawm cov dej condensation, thaum lub sijhawm teb tau tswj hwm nruj kom tiv thaiv kev sib xyaw ntau dhau lossis saw hlau txiav.
Kev siab ncaj qha tswj kev hloov pauv ntawm cov khoom lag luam uas hloov pauv tau. Pib nrog kev siab siab pab txhawb rau qhov pib ua haujlwm, tom qab ntawd qhov siab maj mam txo qis kom yooj yim tshem tawm dej; kev tswj hwm tsis zoo ntawm theem no ua rau cov monomer seem ntau ntxiv thiab tuaj yeem ua rau cov khoom lag luam tsis sib xws. Piv txwv li, kev kho cov qauv siab ntawm reactor los ntawm tsawg li 0.1 MPa tau pom tias txhim kho cov saw hlau molecular uniformity thiab tensile zog los ntawm ntau dua 8% piv rau cov txheej txheem tsis tswj hwm.
Lub pH ntawm cov kua ntsev pib, txawm hais tias tsis yog qhov hloov pauv tseem ceeb thaum lub sijhawm kub siab yaj, muaj feem cuam tshuam rau cov kauj ruam ua ntej lossis tom qab polycondensation. Kev tswj hwm lub pH ze rau qhov nruab nrab (feem ntau ntawm 7 thiab 7.5) yog qhov tseem ceeb rau kev ua tiav qhov sib npaug ntawm stoichiometry ntawm hexamethylenediamine thiab adipic acid, cuam tshuam rau qhov sib npaug ntawm cov saw ntev faib thiab kev txhim kho ntawm cov crystalline domains hauv polymer. pH tsis sib xws tuaj yeem ua rau cov khoom sib xyaw tsis yog stoichiometric, tsav tsheb ntau dhau branching lossis hydrolyzable linkages, uas qhia tau tias yog txo qis lub zog kho tshuab thiab hloov pauv crystallinity hauv cov resin tiav. Cov txheej txheem analytical - xws li differential scanning calorimetry (DSC) thiab X-ray diffraction (XRD) - qhia txog kev nce ntxiv crystalline uniformity thiab txhim kho cov khoom kho tshuab rau pH-optimized nylon 66 qauv.
Kev Ua Polymerization Yaj thiab Kev Txhim Kho Zoo
Kev siv cov nylon 66 yaj hauv kev lag luam ua rau muaj kev sib xyaw ncaj qha yam tsis muaj cov kuab tshuaj, txhawb nqa ob qho tib si kev sib hloov fiber ntau thiab kev tsim cov resin loj. Kev ua tiav qhov hnyav molecular xav tau yog nyob ntawm kev tswj hwm lub sijhawm teb, kub, thiab monomer purities. Kev hloov pauv ntawm cov txheej txheem phiaj xwm feem ntau ua rau muaj kev nce ntxiv ntawm cov viscosity yaj, kev pheej hmoo ntawm kev kub hnyiab hauv zos, thiab txawm tias ua ntej kev sib txuas lossis kev puas tsuaj.
Cov txheej txheem nce qib ua ntu zus, pib nrog ntsev yaj, teb ntawm qhov ntim tas li nyob rau hauv kev tswj hwm siab, thiab tom qab ntawd txo qis siab kom tsav dej tawm. Cov txheej txheem ntsuas qhov ceev ntawm cov kua dej hauv kab ua haujlwm ua cov txheej txheem tawm tswv yim tseem ceeb thaum lub sijhawm no, muab kev saib xyuas tiag tiag kom ntseeg tau tias muaj kev sib npaug thiab ua rau muaj kev hloov kho ntawm cov chaw teeb tsa ua haujlwm rau kev loj hlob zoo tshaj plaws. Cov cuab yeej zoo li lub ntsuas qhov ceev ntawm inline los ntawm Lonnmeter, thaum raug calibrated nrog cov kua calibration uas tau npaj tiav, tso cai rau kev ntsuas qhov tseeb ntawm cov kua ntsev thiab cov polymer yaj qhov ceev. Qhov no ua kom ntseeg tau tias muaj kev sib xws ntawm ib pawg mus rau ib pawg thiab nrhiav tau cov txheej txheem hloov pauv raws sijhawm.
Tom qab polycondensation, cov nylon 66 uas yaj lawm raug extruded thiab tam sim ntawd pelletized. Kev txias sai - feem ntau nrog dej lossis cua yuam - yog qhov tsim nyog los tiv thaiv pellet agglomeration thiab tswj kev ncaj ncees ntawm qhov ntev. Qhov loj me thiab cov duab ntawm pellet tuaj yeem tshwm sim yog tias qhov txias qeeb dhau lossis tsis sib xws, cuam tshuam tsis zoo rau kev tuav thiab ua cov khoom siv hauv qab.
Theem tseem ceeb tom ntej yog ziab. Nylon 66 resin yog hygroscopic ntuj; cov dej seem lossis cov dej nqus ua rau hydrolytic degradation thaum lub sijhawm yaj tom qab, ua rau qhov hnyav molecular txo qis, cov yam ntxwv tsis zoo, thiab pom qhov tsis zoo hauv cov khoom pwm. Kev ziab yuav tsum tau ua nyob rau hauv huab cua qis dew-point, nrog rau qhov kub tswj tsis pub tshaj qhov polymer kam rau siab kom tiv thaiv kev mos ua ntej lossis daj. Kev tshawb fawb qhia tau tias cov dej noo siab tshaj 0.2% ua rau viscosity poob ntau ntxiv thiab txo cov khoom kawg lub zog.
Kev saib xyuas zoo tsis tu ncua, suav nrog Karl Fischer titration rau kev ntsuas dej noo thiab viscosity, yog ib feem ntawm kev coj ua zoo tshaj plaws los xyuas kom meej tias cov txheej txheem ziab ua rau cov pellets ruaj khov, txo qhov tsis zoo. Kev ua kom zoo tshaj plaws txhua kauj ruam ntawm kev ua tiav tom qab - txij li pelletizing mus rau kev khaws cia - tau pom tias ua rau muaj kev sib zog tensile thiab kev cuam tshuam zoo dua piv rau cov txheej txheem tswj hwm tsis zoo.
Kev Ua Kom Muaj Kev Ntseeg Siab Rau Cov Khoom Siv Hauv Cov Kab Khoom Lag Luam
Kev hloov pauv tau yooj yim hauv kev tsim khoom yog qhov tseem ceeb, vim tias cov nylon 66 polymer kev lag luam tau xa mus rau ntau yam kab khoom - cov fibers, cov khoom siv thev naus laus zis, cov yeeb yaj kiab - txhua tus muaj cov kev cai ua haujlwm tshwj xeeb. Qhov no yuav tsum tau hloov kho cov txheej txheem rau txhua qib:
- Cov nylon fiber-qib 66 tau txais txiaj ntsig los ntawm qhov hnyav molecular siab dua rau lub zog kho tshuab, xav tau lub sijhawm polycondensation ntev dua thiab kev ua kom raug dua hauv kev tswj kub.
- Cov qib txhaj tshuaj molding tej zaum yuav tiv taus qhov hnyav molecular qis dua tab sis xav tau pellet qhuav thiab geometric precision kom tiv thaiv kev ua tsis zoo.
Kev kuaj xyuas qhov zoo kawg nkaus yog nyob ntawm cov qauv kev lees txais tshwj xeeb ntawm cov khoom. Cov no suav nrog cov kev ntsuas tus qauv ntawm cov viscosity intrinsic, modulus, kev tiv thaiv kev cuam tshuam, thiab, qhov tseem ceeb, cov dej noo. Kev kuaj xyuas lub cev rau qhov sib xws ntawm pellet thiab tsis muaj kev hloov pauv tau txhawb nqa los ntawm kev ntsuam xyuas hauv chaw soj ntsuam ntawm cov khoom siv kho tshuab thiab thermal. Tsuas yog cov pawg ua tau raws li txhua qhov ntsuas tseem ceeb thiaj li tso tawm rau kev siv hauv kev lag luam - cov ntsiab lus tau muab tso ua ke hauv cov ntawv qhia txog kev siv tshuab uas siv ASTM thiab ISO cov txheej txheem.
Kev saib xyuas qhov ceev kuj ua lub luag haujlwm tiv thaiv; kev siv cov txheej txheem ntsuas qhov ceev ntawm cov kua thaum lub sijhawm npaj ntsev thiab cov polymer yaj ua kom ntseeg tau tias cov khoom sib xyaw zoo ib yam thiab ua rau pom sai sai ntawm qhov sib txawv uas yuav ua rau muaj kev ntseeg siab rau kev siv kawg. Kev kho qhov ceev ntawm cov ntsuas qhov ceev, xws li cov uas tsim los ntawm Lonnmeter, yog ua tiav nrog cov qauv ntawv pov thawj kom tswj tau cov txheej txheem nruj thiab rov ua dua, qhov tseem ceeb rau kev nthuav dav ntawm ntau cov kab khoom lag luam.
Los ntawm kev tswj hwm nruj thaum lub sijhawm ua ntej-polycondensation, kev ua kom yaj polymerization meej, thiab kev ua tiav tom qab nruj, cov chaw tsim khoom nylon 66 ib txwm xa cov resins txhim khu kev qha, daim ntawv thov tshwj xeeb uas ua tau raws li qhov xav tau ntawm cov khoom lag luam kev lag luam.
Cov Lus Nug Feem Ntau (FAQs)
Nylon 66 ntsev yog dab tsi, thiab vim li cas nws thiaj li tseem ceeb hauv kev tsim cov polymer?
Nylon 66 ntsev, hu ua hexamethylenediammonium adipate, ua lub hauv paus ntawm nylon 66 polymer ntau lawm. Nws yog tsim los ntawm kev sib xyaw ua ke ntawm hexamethylenediamine thiab adipic acid hauv qhov sib piv 1:1. Qhov nruab nrab no tswj cov ntsiab lus kawg ntawm pawg thiab qhov ntev ntawm cov polyamide kawg. Cov ntsev nylon 66 uas muaj purity siab yog qhov tsim nyog los ua kom muaj zog sib xws, kev ruaj khov thermal, thiab kev tiv thaiv kev hnav hauv cov yas engineering. Off-stoichiometry lossis cov khoom tsis huv hauv cov kauj ruam no ua rau kev ua haujlwm ntawm polymerization tom qab ntawd tsis zoo thiab txo qhov zoo ntawm cov khoom kawg, ua rau kev npaj ntsev yog qhov tseem ceeb hauv cov txheej txheem tsim khoom nylon 66 polymer.
Cov txheej txheem npaj ntsev nylon 66 tau ua kom zoo li cas rau kev huv?
Cov txheej txheem tsim cov ntsev nylon 66 vam khom kev tswj hwm, maj mam ntxiv cov tshuaj reactants. Kev sib cais lossis poob ntxiv ntawm hexamethylenediamine rau hauv adipic acid nyob rau hauv kev tswj hwm kub nruj, feem ntau ntawm 210 ° C thiab 1.8 MPa, txo qis qhov ntau dhau hauv zos, tiv thaiv cov khoom tsis xav tau, thiab ua kom muaj qhov sib piv stoichiometric. Cov roj inert, xws li nitrogen, tiv thaiv cov tshuaj tiv thaiv los ntawm kev oxidation tsis xav tau. Kev saib xyuas pH thiab UV index tas mus li lees paub qhov xwm txheej ze-nruab nrab thiab tsis muaj cov khoom xim, uas yog cov cim ntawm cov ntsev siab-purity. Cov txheej txheem tswj hwm no tso cai rau kev tsim cov tshuaj ntsev tsis muaj xim, ruaj khov, thiab cov tshuaj tiv thaiv uas tsim nyog rau kev sib xyaw ncaj qha.
Qhov tseem ceeb ntawm kev saib xyuas qhov ceev hauv cov txheej txheem npaj ntsev yog dab tsi?
Kev saib xyuas qhov ceev ntawm cov kua ntsev yog qhov tseem ceeb rau kev tswj cov txheej txheem thiab kev paub tseeb zoo thaum lub sijhawm npaj ntsev nylon 66. Qhov ceev ntawm cov kua, ntsuas hauv lub sijhawm tiag tiag, yog tus sawv cev ncaj qha rau kev sib sau ua ke thiab kev ua tiav ntawm cov tshuaj tiv thaiv neutralization. Cov nqi ruaj khov, lub hom phiaj ceev xyuas kom meej tias qhov piv ntawm reactant raug tswj thiab kev hloov pauv tau mus txog qhov tiav. Qhov no pab txo qhov kev hloov pauv hauv kev sib xyaw ua ke, txwv tsis pub muaj cov feem me me, thiab txhawb nqa kev tsim khoom zoo sib xws. Kev siv lub ntsuas ceev ntawm cov kua ua kom ntseeg tau tias cov kev ntsuas no tseem nyob hauv cov kev txwv ua haujlwm nruj, txhawb kev ntseeg siab thoob plaws cov kab khoom lag luam tshuaj lom neeg.
Cov tshuaj tiv thaiv neutralization ua haujlwm li cas hauv kev npaj ntsev nylon 66?
Hauv cov tshuaj tiv thaiv ntsev nylon 66, hexamethylenediamine (lub hauv paus diamine) reacts nrog adipic acid (lub dicarboxylic acid) hauv cov nqi stoichiometric. Qhov tshuaj tiv thaiv yog qhov tsis muaj zog: NH2-(CH2)6-NH2 + HOOC-(CH2)4-COOH → (NH3+)-(CH2)6-(NH3+)(-OOC-(CH2)4-COO-) + H2O. Rau kev tsim ntsev zoo tagnrho, cov txheej txheem yuav tsum tau tswj hwm qhov tseeb ntawm kev ntxiv reactant, kub, thiab pH, vim tias txawm tias qhov sib txawv me me tuaj yeem ua rau kev hloov pauv tsis tiav lossis cov tshuaj tiv thaiv sab tsis xav tau. Qhov ua tau zoo ntawm cov tshuaj tiv thaiv no txiav txim siab cov qauv molecular thiab kev ua tau zoo ntawm cov nylon 66 polymer.
Cov khoom siv twg siv rau kev ntsuas qhov ceev ntawm cov kua hauv kev tsim cov ntsev nylon 66 hauv kev lag luam?
Kev ntsuas qhov ntom ntawm cov kua ntsev yog lub hauv paus ntawm kev lees paub cov txheej txheem hauv kev tsim cov nylon 66 loj. Cov ntsuas qhov ntom ntawm cov kua hauv kab, xws li oscillating U-tube densitometers, feem ntau siv rau hauv kev teeb tsa kev lag luam. Cov cuab yeej no xa cov ntawv nyeem qhov ntom ntawm cov kua tas mus li, lub sijhawm tiag tiag, uas pab cov neeg ua haujlwm kho cov nqi pub, cov piv ntawm cov tshuaj reactant, thiab cov xwm txheej thermal kom phim cov txheej txheem tshwj xeeb. Lonnmeter tsim cov ntsuas qhov ntom ntawm cov kab thiab cov ntsuas viscosity hauv kab uas zoo rau qib kev siv hauv kev lag luam no. Kev ntsuas cov khoom siv no tsis tu ncua ua kom ntseeg tau tias muaj kev ua tau zoo thiab rov ua dua, uas yog qhov tseem ceeb rau kev tswj hwm kev ncaj ncees ntawm cov khoom siv tshuaj thiab txhawb nqa kev tswj hwm zoo.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-18-2025
