Polyurethane elastomers yog ib hom khoom siv polymer ua tau zoo heev. Nrog lawv cov yam ntxwv tshwj xeeb ntawm lub cev thiab tshuaj lom neeg thiab kev ua tau zoo heev, lawv nyob hauv txoj haujlwm tseem ceeb hauv kev lag luam niaj hnub no. Cov ntaub ntawv no siv dav hauv ntau qhov chaw tsim khoom siab, xws li aerospace, tsheb siab, tshuab precision, khoom siv hluav taws xob thiab khoom siv kho mob, vim lawv qhov elasticity zoo, hnav tsis kam, corrosion tsis kam thiab ua haujlwm yooj yim. Nrog rau kev nce qib ntawm kev tshawb fawb thiab thev naus laus zis thiab kev txhim kho tas mus li ntawm cov khoom siv ua tau zoo hauv kev lag luam tsim khoom, kev tsim cov khoom ua tau zoo ntawm polyurethane elastomers tau dhau los ua qhov tseem ceeb hauv kev txhim kho lawv cov nqi siv. Hauv kev lag luam tsim khoom siab, cov kev cai ua tau zoo rau cov ntaub ntawv tau dhau los ua qhov nruj dua. Ua ib yam khoom siv ua tau zoo, kev tsim thiab kev siv polyurethane elastomers yuav tsum ua tau raws li cov qauv kev siv tshuab tshwj xeeb. Kev siv polyurethane elastomers hauv kev tsim khoom siab kuj ntsib ntau yam teeb meem, suav nrog kev tswj tus nqi, kev siv tshuab thiab kev lees txais kev lag luam. Txawm li cas los xij, nrog nws cov txiaj ntsig kev ua tau zoo, polyurethane elastomers tau ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua tau zoo thiab kev sib tw ntawm cov khoom tsim khoom. Los ntawm kev tshawb fawb tob txog cov teb no, nws tuaj yeem muab kev txhawb nqa zoo rau kev txhim kho cov khoom siv tsim thiab nthuav dav cov ntawv thov.

 

Kev tsim qauv zoo ntawm polyurethane elastomers

 

Cov khoom siv sib xyaw thiab cov kev cai ua tau zoo

Polyurethane elastomers yog ib chav kawm ntawm cov ntaub ntawv polymer uas muaj kev ua tau zoo heev. Lawv feem ntau yog tsim los ntawm ob lub hauv paus tseem ceeb: polyether thiab isocyanate. Kev xaiv thiab kev sib piv ntawm cov khoom no muaj kev cuam tshuam loj rau kev ua tau zoo ntawm cov khoom kawg. Polyether feem ntau yog qhov tseem ceeb ntawm cov polyurethane elastomers. Nws cov qauv molecular muaj cov pawg polyol, uas tuaj yeem muab kev ywj pheej zoo thiab kev ywj pheej. Isocyanate, ua lub ntsiab lus tseem ceeb ntawm cov khoom tawv, yog lub luag haujlwm rau kev cuam tshuam nrog polyether los tsim cov saw polyurethane, txhim kho lub zog thiab kev hnav tsis kam ntawm cov khoom. Ntau hom polyethers thiab isocyanates muaj cov khoom siv tshuaj lom neeg thiab cov khoom siv lub cev sib txawv. Yog li ntawd, hauv kev tsim cov polyurethane elastomers, nws yog qhov tsim nyog los xaiv thiab sib piv cov khoom no raws li qhov yuav tsum tau ua kom tiav cov ntsuas kev ua tau zoo. Hauv cov nqe lus ntawm kev ua tau zoo, polyurethane elastomers yuav tsum muaj ntau yam tseem ceeb: hnav tsis kam, elasticity, tiv thaiv kev laus, thiab lwm yam. Hnav tsis kam txhais tau tias kev ua tau zoo ntev ntawm cov khoom hauv qab kev sib txhuam thiab kev hnav tsis kam. Tshwj xeeb tshaj yog thaum siv rau hauv qhov chaw uas muaj kev hnav ntau, xws li cov tshuab ncua tsheb thiab cov khoom siv hauv kev lag luam, kev tiv thaiv kev hnav zoo tuaj yeem ua rau lub neej ua haujlwm ntawm cov khoom ntev dua. Elasticity yog ib qho ntawm cov khoom tseem ceeb ntawm polyurethane elastomers. Nws txiav txim siab seb cov khoom puas tuaj yeem rov qab mus rau nws cov duab qub thaum lub sijhawm deformation thiab rov zoo. Nws yog siv dav hauv cov foob thiab cov absorbers poob siab. Kev tiv thaiv kev laus txhais tau hais tias cov khoom siv muaj peev xwm tswj nws cov kev ua tau zoo tom qab siv ntev lossis raug rau qhov chaw ib puag ncig hnyav (xws li ultraviolet rays, noo noo, kev hloov pauv kub, thiab lwm yam), kom ntseeg tau tias cov khoom siv tswj kev ua tau zoo ruaj khov hauv kev siv.

 

Cov Tswv Yim Txhim Kho Kev Tsim Qauv

Kev tsim cov polyurethane elastomers uas muaj kev ua tau zoo yog ib qho txheej txheem nyuaj thiab nyuaj heev uas yuav tsum tau xav txog ntau txoj kev txhim kho kev tsim qauv. Kev ua kom zoo dua ntawm cov qauv molecular yog ib kauj ruam tseem ceeb hauv kev txhim kho kev ua tau zoo ntawm cov khoom siv. Los ntawm kev kho cov qauv molecular saw ntawm polyurethane, xws li kev nce qib ntawm kev sib txuas, lub zog kho tshuab thiab kev tiv thaiv kev hnav ntawm cov khoom siv tuaj yeem txhim kho tau zoo heev. Kev nce qib ntawm kev sib txuas ua rau muaj cov qauv network ruaj khov dua los tsim ntawm cov saw molecular ntawm cov khoom siv, yog li ua kom nws lub zog thiab kev ruaj khov tag nrho. Piv txwv li, los ntawm kev siv cov tshuaj polyisocyanate reactants lossis kev qhia cov neeg sawv cev sib txuas, qib ntawm kev sib txuas tuaj yeem nce ntxiv thiab kev ua tau zoo ntawm cov khoom siv tuaj yeem ua kom zoo dua. Kev ua kom zoo dua ntawm qhov sib piv ntawm cov khoom kuj tseem ceeb. Qhov sib piv ntawm polyether thiab isocyanate cuam tshuam ncaj qha rau qhov elasticity, hardness thiab hnav tsis kam ntawm cov khoom siv. Feem ntau, kev nce qhov sib piv ntawm isocyanate tuaj yeem ua rau qhov nyuaj thiab hnav tsis kam ntawm cov khoom siv, tab sis yuav txo nws qhov elasticity. Yog li ntawd, nws yog qhov tsim nyog los kho qhov sib piv ntawm ob qho raws li qhov xav tau tiag tiag kom ua tiav qhov sib npaug zoo tshaj plaws. Ntxiv rau qhov kev ua kom zoo dua ntawm cov qauv molecular thiab cov khoom sib piv, kev siv cov khoom ntxiv thiab cov neeg sawv cev txhawb nqa kuj muaj kev cuam tshuam loj rau kev ua haujlwm ntawm cov khoom siv. Nanomaterials, xws li nano-silicon thiab nano-carbon, tuaj yeem txhim kho kev ua tau zoo ntawm polyurethane elastomers. Nanomaterials txhim kho cov khoom siv kho tshuab thiab kev tiv thaiv ib puag ncig ntawm cov ntaub ntawv los ntawm kev ua kom lawv lub zog, kev hnav tsis kam thiab kev laus tsis kam.

 

 

Kev txhim kho ntawm cov txheej txheem npaj

Kev txhim kho cov txheej txheem npaj yog ib txoj hauv kev tseem ceeb los txhim kho kev ua tau zoo ntawm polyurethane elastomers. Kev nce qib hauv cov thev naus laus zis polymer synthesis tau muaj kev cuam tshuam loj heev rau kev npaj polyurethane elastomers. Cov txheej txheem niaj hnub polymer synthesis, xws li kev txhaj tshuaj molding (RIM) thiab cov thev naus laus zis polymerization siab, tuaj yeem ua tiav kev tswj hwm kom meej dua thaum lub sijhawm ua cov txheej txheem synthesis, yog li ua kom zoo dua cov qauv molecular thiab kev ua tau zoo ntawm cov khoom. Cov thev naus laus zis txhaj tshuaj molding tuaj yeem txhim kho kev ua haujlwm ntau lawm thiab ua tiav cov khoom zoo dua thiab sib xws thaum lub sijhawm molding los ntawm kev sib xyaw polyether thiab isocyanate sai sai hauv qab siab thiab txhaj rau hauv pwm. Cov thev naus laus zis polymerization siab tuaj yeem txhim kho qhov ceev thiab lub zog ntawm cov khoom thiab txhim kho nws txoj kev tiv thaiv kev hnav thiab kev tiv thaiv kev laus los ntawm kev ua cov tshuaj tiv thaiv polymerization hauv qab siab. Kev txhim kho molding thiab kev ua cov thev naus laus zis kuj yog qhov tseem ceeb hauv kev txhim kho kev ua tau zoo ntawm polyurethane elastomers. Cov txheej txheem molding kub kub ib txwm tau hloov maj mam los ntawm cov thev naus laus zis txhaj tshuaj molding thiab extrusion molding siab dua. Cov txheej txheem tshiab no tsis tsuas yog tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom, tab sis kuj ua tiav kev tswj hwm kom meej dua thaum lub sijhawm molding kom ntseeg tau tias qhov zoo thiab kev ua tau zoo ntawm cov khoom. Kev siv tshuab txhaj tshuaj molding tuaj yeem ua tiav kev txhaj tshuaj pwm ntawm cov duab nyuaj thiab txo cov khoom pov tseg los ntawm kev ua kom cov khoom siv polyurethane raw sov rau hauv lub xeev molten thiab txhaj rau hauv pwm. Kev siv tshuab extrusion molding ua kom sov thiab yuam cov khoom siv polyurethane tawm ntawm lub extruder, tsim cov khoom siv txuas ntxiv mus los ntawm kev txias thiab khov. Nws yog qhov tsim nyog rau kev tsim khoom loj thiab kev ua tiav raws li qhov xav tau.

 

Kev siv cov polyurethane elastomers hauv kev tsim khoom siab heev

 

Kev tsav dav hlau

Hauv kev lag luam aerospace, polyurethane elastomers siv dav hauv ntau yam khoom tseem ceeb, xws li cov foob thiab cov khoom nqus dej, vim lawv muaj kev ua tau zoo heev. Kev lag luam aerospace muaj cov kev cai nruj heev rau kev ua tau zoo ntawm cov ntaub ntawv, uas feem ntau suav nrog kev tiv taus kub siab, kev tiv taus qaug zog, kev tiv taus tshuaj lom neeg, kev tiv taus hnav, thiab lwm yam. Kev ua tau zoo ntawm polyurethane elastomers hauv cov yam no ua rau nws yog ib qho ntawm cov ntaub ntawv tseem ceeb hauv kev lag luam aerospace. Piv txwv li, cov foob. Hauv lub tshuab roj ntawm cov tsheb aerospace, cov foob yuav tsum tswj kev sib khi zoo hauv qab qhov kub thiab txias heev. Lub tshuab roj ntawm cov tsheb aerospace feem ntau raug rau qhov kub thiab txias siab, siab siab thiab cov xov xwm corrosive. Yog li ntawd, cov foob yuav tsum tsis tsuas yog tiv taus qhov kub thiab txias siab, tab sis kuj tiv taus tshuaj lom neeg corrosion. Polyurethane elastomers, tshwj xeeb tshaj yog cov polyurethanes ua tau zoo uas tau kho ntawm qhov kub thiab txias siab, muaj kev tiv taus kub thiab tuaj yeem tiv taus qhov chaw ua haujlwm siab dua 300 ° C. Tib lub sijhawm, qhov elasticity zoo ntawm polyurethane elastomers ua rau lawv tuaj yeem sau cov chaw tsis sib xws thiab xyuas kom meej tias cov foob ruaj khov thiab kev ntseeg siab hauv kev siv mus sij hawm ntev. Piv txwv li, cov foob siv hauv NASA lub chaw thauj mus los hauv ntiaj teb thiab chaw nres tsheb hauv ntiaj teb siv polyurethane elastomers, uas qhia txog kev ua haujlwm zoo heev thiab kev ua haujlwm ntev hauv qhov chaw ib puag ncig hnyav. Lwm qhov yog cov khoom nqus dej. Hauv kev tsav dav hlau, cov khoom nqus dej siv los txo qhov cuam tshuam ntawm kev co thiab kev poob siab ntawm cov khoom tseem ceeb. Polyurethane elastomers ua lub luag haujlwm tseem ceeb hauv cov ntawv thov zoo li no. Lawv qhov elasticity zoo heev thiab lub peev xwm nqus tau lub zog zoo ua rau lawv tuaj yeem ua kom zoo thiab txo qhov kev co thiab kev poob siab, yog li tiv thaiv cov qauv thiab cov khoom siv hluav taws xob ntawm kev tsav dav hlau.

 

 Kev lag luam tsheb siab heev

Hauv kev lag luam tsheb kim heev, kev siv polyurethane elastomers tau dhau los ua qhov tseem ceeb hauv kev txhim kho kev ua haujlwm thiab kev nplij siab ntawm lub tsheb. Vim nws muaj kev ua tau zoo heev, polyurethane elastomers tau siv dav hauv ntau yam khoom tseem ceeb ntawm lub tsheb, suav nrog cov tshuab nqus dej, cov foob, cov khoom sab hauv, thiab lwm yam. Piv txwv li, piv txwv li, cov khoom nqus dej hauv lub tshuab ncua ntawm cov tsheb kim heev, kev siv polyurethane elastomers tau txhim kho kev nplij siab thiab kev ruaj khov ntawm lub tsheb. Hauv lub tshuab ncua, polyurethane elastomers nqus tau qhov cuam tshuam thiab kev co ntawm txoj kev thiab txo qhov kev co ntawm lub cev tsheb los ntawm lawv cov khoom zoo heev thiab kev nqus dej. Qhov zoo heev ntawm cov khoom siv no ua kom lub tshuab ncua ntawm lub tsheb tuaj yeem teb sai sai hauv ntau yam kev tsav tsheb thiab muab kev tsav tsheb du thiab xis dua. Tshwj xeeb tshaj yog hauv cov qauv kim heev, cov khoom nqus dej zoo siv polyurethane elastomers tuaj yeem txhim kho kev nplij siab ntawm kev caij tsheb thiab ua tau raws li qhov yuav tsum tau ua rau kev tsav tsheb zoo. Hauv cov tsheb kim heev, kev ua tau zoo ntawm cov foob cuam tshuam ncaj qha rau kev rwb thaiv suab, rwb thaiv cua sov thiab kev ua haujlwm tsis muaj dej ntawm lub tsheb. Cov polyurethane elastomers siv dav hauv cov foob rau lub qhov rooj thiab qhov rai tsheb, chav cav thiab hauv qab vim lawv qhov kev sib khi zoo heev thiab tiv taus huab cua. Cov chaw tsim khoom tsheb siab siv polyurethane elastomers ua cov foob qhov rooj kom txhim kho lub suab rwb thaiv tsev ntawm lub tsheb thiab txo qhov nkag ntawm suab nrov sab nraud.