Tib neeg tau siv tej yam ntuj tso polymeric ntaub ntawv xws li ntoo, tawv thiab ntaub plaub txij thaum pib ntawm keeb kwm, tab sis hluavtaws polymers ua tau tsuas yog tom qab kev loj hlob ntawm roj hmab technology nyob rau hauv 1800s.Lub Ž rst hluavtaws polymer khoom, celluloid, tau tsim los ntawm John Wesley Hyatt hauv xyoo 1869, los ntawm cellulose nitrate thiab camphor.Ib qho kev ua txhaum loj hauv cov khoom siv hluavtaws yog qhov kev tsim ntawm Bakelite los ntawm Leo Hendrik Baekeland hauv xyoo 1907. Hermann Staudinger txoj haujlwm hauv xyoo 1920 tau qhia meej meej txog macromolecular xwm ntawm cov saw ntev ntawm kev rov ua dua units.1 lo lus 'polymer' los ntawm Greek, thiab nws txhais tau tias 'many. qhov chaw'.Kev loj hlob sai ntawm kev lag luam polymer pib sai ua ntej Tsov Rog Ntiaj Teb Zaum Ob, nrog rau kev txhim kho ntawm acrylic polymers, polystyrene, nylon, polyurethanes thiab tom qab kev taw qhia ntawm polyethylene, polyethylene terephthalate, polypropylene thiab lwm yam polymers nyob rau hauv 1940s thiab 1950s.Thaum tsuas yog kwv yees li ntawm 1 lab tons tau tsim nyob rau xyoo 1945, kev tsim cov yas hauv ntim tau dhau ntawm cov hlau hauv xyoo 1981, thiab qhov sib txawv tau loj hlob tsis tu ncua txij li thaum.
Pure polymers tsis tshua ua tiav ntawm lawv tus kheej.Lawv raug muab sib xyaw nrog lwm cov ntaub ntawv, feem ntau yog los ntawm kev sib xyaw ua ke los yog yaj lub xeev sib tov los tsim cov pellets, hmoov lossis akes los siv rau hauv kev ua haujlwm tom ntej.2 Cov khoom sib xyaw ua ke no hu ua 'plastics', uas txhais tau tias 'pliables' hauv Greek.Lub tebchaw yuav koom nrog Ž llers (kom txo nqi), kev txhawb zog, lwm yam polymers, colourants, ame retardants, stabilizers (kom tiv thaiv kev puas tsuaj los ntawm lub teeb, tshav kub lossis lwm yam khoom ib puag ncig) thiab ntau yam kev pab cuam.
Synthetic polymers tuaj yeem muab faib ua ob pawg.Thermoplastics (nyob deb ntawm qhov loj tshaj plaws) tuaj yeem yaj los ntawm cua sov, solidiŽ ed los ntawm txias thiab remelted dua.Cov hom loj yog polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET) thiab polyamide (PA, nylon).Thermosets yog hardened los ntawm daim ntawv thov ntawm tshav kub thiab siab, vim yog crosslinking, piv txwv li cov creation ntawm mus tas li peb-dimensional tes hauj lwm.Lawv tsis tuaj yeem softened los ntawm cua sov rau reprocessing.Bakelite, epoxy thiab feem ntau polyurethanes yog thermosets.
Lub ntsiab lus tam sim no tsuas yog mob siab rau kev ua cov thermoplastics.Kev lag luam thermoplastics yog classiŽ ed raws li lawv cov kev ua tau zoo li 'cov khoom' (kev ua haujlwm qis, xws li PE, PP, PS thiab PVC), 'Engineering' (xws li PC, nylon thiab PET) lossis 'siab tshaj' (kev ua tau zoo tshaj plaws, xws li kua siv lead ua polymers (LCPs), polyphenylene sulphide (PPS) thiab polyetheretherketone (PEEK)).Qhov kev cia siab tias tawg loj hlob hauv engineering thiab qib siab polymers tsis tau tsim.Kev siv cov plastics tau loj hlob tsis tu ncua thoob plaws hauv peb lub xyoos dhau los, tab sis feem ntau hauv cov khoom lag luam.Tam sim no, cov khoom siv polymers muaj li ~ 88% ntawm cov ntim tsim, 3 engineering plastics ~ 12% thiab qib siab tsawg dua 1%.Txawm hais tias tus nqi ntawm cov khoom siv polymers siab tshaj ib kilogram ntau dua li cov khoom siv polymers, lawv cov nqi thoob ntiaj teb rau kev lag luam tseem tsawg heev.
Cov khoom lag luam yas muaj qhov tsis tshua muaj zog thiab tawv thaum piv nrog cov hlau lossis ceramics, thiab lawv zoo li nthuav tawm hauv qab lub zog siv.Lawv kuj muaj kev txwv kub hauv lawv cov khoom siv (feem ntau yaj hauv thaj tsam 100-250 ° C).Lub tensile moduli ntawm cov khoom yas yog ~ 1 GPa (piv nrog 210 GPa rau hlau).Kev txhim kho Signi-Ž tsis tuaj yeem ua tiav los ntawm kev sib dhos ntawm cov saw hlau polymer.Qhov tseeb, cov pa roj carbon- carbon bonds muaj zog heev, thiab ib leeg Ž lament polyethylene tau tsim nrog cov nqi sib tw tshaj li ntawm cov hlau.Kev taw qhia siab tuaj yeem ua tiav los ntawm kev ua haujlwm tshwj xeeb, piv txwv li extrusion thiab tom qab kos duab ntawm qhov kub thiab txias.Ntawm qhov kub thiab txias, cov saw hlau polymer tsis muaj kev txav mus los, thiab kev taw qhia tseem nyob tom qab ncab.Kev tshawb pom tsis ntev los no thiab kev txhim kho ntawm ib qhov chaw, metallocene raws li catalysts tau ua rau cov qib tshiab ntawm cov khoom lag luam polymers tau tswj hwm cov qauv molecular nrog cov khoom txhim kho.
Lub ntiaj teb kev tsim cov polymers tau nce 3 los ntawm 27 lab tons hauv 1975 txog ~ 200 lab tons hauv ib xyoos hauv 2000 thiab tseem loj hlob.Raws li tsab ntawv ceeb toom tsis ntev los no, 4 kev xa khoom ntawm cov khoom yas hauv Tebchaws Meskas hauv xyoo 2000 yog li $ 330 nphom, thiab cov khoom siv hluav taws xob sab saud tau muag txog $ 90 billion, nqa tag nrho txhua xyoo rau $ 420 billion.Tag nrho kev ua haujlwm tau kwv yees li 2 .4 lab - kwv yees li 2% ntawm Asmeskas cov neeg ua haujlwm.Kev loj hlob ntawm kev lag luam polymer yog tshwm sim los ntawm kev sib xyaw tshwj xeeb ntawm cov khoom yas, uas suav nrog kev yooj yim shaping thiab fabrication, tsis tshua muaj ntom, tiv thaiv corrosion, hluav taws xob thiab thermal rwb thaiv tsev, thiab feem ntau zoo rigidity thiab toughness ntawm ib chav tsev qhov hnyav.
Post lub sij hawm: Feb-04-2018