Los ntawm nws qhov pib thaum ntxov thiab tom qab Tsov Rog Thoob Ntiaj Teb thib 2, kev lag luam kev lag luam rau cov khoom siv polymers-ntev-chain hluavtaws molecules uas "yas" yog ib qho tsis zoo - tau loj hlob sai.Hauv xyoo 2015, ntau tshaj 320 lab tons ntawm polymers, tsis suav nrog fibers, tau tsim thoob plaws ntiaj teb.
[Daim duab: Kev Sib Tham] Txog rau tsib xyoos dhau los, cov neeg tsim khoom lag luam polymer feem ntau tsis xav tias yuav muaj dab tsi tshwm sim tom qab qhov kawg ntawm lawv cov khoom pib lub neej.Qhov no pib hloov pauv, thiab qhov teeb meem no yuav xav tau kev tsom mus rau ntau xyoo tom ntej.
LUB PLASTICS kev lag luam
"Plastic" tau dhau los ua qhov yuam kev me ntsis los piav txog cov polymers.Feem ntau muab tau los ntawm cov roj av lossis cov nkev ntuj, cov no yog cov saw hlau ntev nrog ntau pua mus rau ntau txhiab qhov txuas hauv txhua txoj saw.Cov chains ntev qhia cov khoom tseem ceeb ntawm lub cev, xws li lub zog thiab tawv, uas luv luv molecules tsis tuaj yeem phim.
"Plastic" tiag tiag yog ib daim ntawv luv luv ntawm "thermoplastic," ib lo lus uas piav qhia txog cov khoom siv polymeric uas tuaj yeem ua kom zoo li qub thiab rov ua dua tshiab siv cov cua sov.
Kev lag luam polymer niaj hnub tau tsim tau zoo los ntawm Wallace Carothers ntawm DuPont hauv xyoo 1930.Nws qhov kev mob siab ua haujlwm ntawm polyamides tau coj mus rau kev lag luam ntawm nylon, raws li kev ua tsov rog tsis txaus ntawm cov ntaub ntawv yuam cov poj niam mus saib lwm qhov rau cov hnab ntim khoom.
Thaum lwm cov ntaub ntawv tsis tshua muaj thaum Tsov Rog Ntiaj Teb Zaum II, cov kws tshawb fawb tau saib rau cov khoom siv hluavtaws los ua qhov khoob.Piv txwv li, kev muab cov roj hmab ntuj rau lub tsheb log tsheb raug txiav tawm los ntawm Nyiv kev kov yeej ntawm cov teb chaws Esxias sab hnub tuaj, ua rau cov khoom siv hluavtaws sib npaug.
Kev xav-tsav kev ua tiav hauv chemistry coj mus rau kev txhim kho ntxiv ntawm cov khoom siv hluavtaws, suav nrog tam sim no siv polypropylene thiab high-density polyethylene.Qee cov polymers, xws li Teflon, tau ntog los ntawm kev sib tsoo.
Thaum kawg, kev sib xyaw ua ke ntawm kev xav tau, kev nce qib hauv kev tshawb fawb, thiab kev ua siab ntev coj mus rau tag nrho cov khoom siv polymers uas tam sim no koj tuaj yeem lees paub tau zoo li "yas".Cov polymers no tau ua lag luam sai heev, ua tsaug rau lub siab xav txo cov khoom hnyav thiab muab cov khoom pheej yig rau cov khoom siv ntuj xws li cellulose lossis paj rwb.
Hom Plastics
Kev tsim cov khoom siv hluav taws xob thoob ntiaj teb yog tswj hwm los ntawm polyolefins-polyethylene thiab polypropylene.
Polyethylene los ntawm ob hom: "siab ceev" thiab "tsawg ceev."Nyob rau hauv molecular nplai, high-density polyethylene zoo li ib tug zuag nrog tsis tu ncua spaced, luv cov hniav.Qhov qis-density version, ntawm qhov tod tes, zoo li lub zuag nrog cov hniav tsis tu ncua ntawm qhov ntev-zoo li tus dej thiab nws cov tributaries yog pom los ntawm qhov siab saum toj no.Txawm hais tias lawv yog ob qho tib si polyethylene, qhov sib txawv ntawm cov duab ua rau cov ntaub ntawv no coj txawv txawv thaum molded rau hauv cov yeeb yaj kiab lossis lwm yam khoom.
[Daim duab: Kev Sib Tham]
Polyolefins yog qhov tseem ceeb rau ob peb yam.Ua ntej, lawv tuaj yeem tsim tau siv cov khoom siv hluav taws xob pheej yig.Qhov thib ob, lawv yog cov hluavtaws hluavtaws uas tsim los ntawm cov nplai loj;lawv qhov ntom ntom ntom nti kom lawv ntab.Thib peb, polyolefins tiv thaiv kev puas tsuaj los ntawm dej, huab cua, roj, ntxuav cov kuab tshuaj - txhua yam uas cov polymers tuaj yeem ntsib thaum siv.Thaum kawg, lawv yooj yim los tsim rau hauv cov khoom, thaum muaj zog txaus uas ntim tau los ntawm lawv yuav tsis deform nyob rau hauv lub tsheb thauj khoom zaum hauv lub hnub txhua hnub.
Txawm li cas los xij, cov ntaub ntawv no muaj qhov tsis zoo.Lawv degrade mob maj mam, txhais tau hais tias polyolefins yuav ciaj sia nyob rau hauv ib puag ncig rau xyoo mus rau centuries.Lub caij no, nthwv dej thiab cua ua haujlwm mechanically abrades lawv, tsim microparticles uas tuaj yeem noj los ntawm cov ntses thiab tsiaj txhu, ua rau lawv txoj hauv kev nce cov khoom noj rau peb.
Recycling polyolefins tsis yog ib qho yooj yim raws li ib tug xav tau vim yog kev sau thiab tu cov teeb meem.Oxygen thiab cua sov ua rau cov saw hlau puas thaum lub sij hawm reprocessing, thaum zaub mov thiab lwm yam ntaub ntawv kis tau tus mob polyolefin.Kev nce qib ntxiv hauv chemistry tau tsim cov qib tshiab ntawm polyolefins nrog kev txhim kho lub zog thiab kav ntev, tab sis cov no tsis tuaj yeem sib xyaw nrog lwm qib thaum rov ua dua.Dab tsi ntxiv, polyolefins feem ntau ua ke nrog lwm cov ntaub ntawv hauv ntau txheej ntim.Thaum cov txheej txheem ntau txheej ua haujlwm zoo, lawv tsis tuaj yeem rov ua dua tshiab.
Polymers qee zaum raug thuam vim yog tsim los ntawm cov roj av tsis tshua muaj thiab cov nkev ntuj.Txawm li cas los xij, feem ntau ntawm cov roj av lossis roj av siv los tsim cov polymers tsawg heev;tsawg dua 5% ntawm cov roj lossis cov nkev uas tsim tawm txhua xyoo yog ua haujlwm los tsim cov yas.Tsis tas li ntawd, ethylene tuaj yeem tsim los ntawm cov ethanol, uas yog ua lag luam los ntawm Braskem hauv Brazil.
YUAV UA LI CAS Plastics
Nyob ntawm thaj tsam, ntim khoom siv 35% mus rau 45% ntawm cov khoom siv hluavtaws tsim nyob rau hauv tag nrho, qhov twg polyolefins dominate.Polyethylene terephthalate, polyester, dominates kev lag luam rau lub raj mis dej haus thiab textile fibers.
Lub tsev thiab kev tsim kho siv lwm 20% ntawm tag nrho cov polymers tsim, qhov twg PVC yeeb nkab thiab nws cov kwv tij txheeb ze tshuaj.Cov kav dej PVC yog lub teeb yuag, tuaj yeem ua tau nplaum ntau dua li soldered lossis welded, thiab tiv thaiv kev puas tsuaj ntawm cov tshuaj chlorine hauv dej.Hmoov tsis zoo, cov tshuaj chlorine atoms uas muab PVC qhov zoo dua ua rau nws nyuaj heev rau rov ua dua-feem ntau yog muab pov tseg thaum kawg ntawm lub neej.
Polyurethanes, tag nrho tsev neeg ntawm cov polymers uas muaj feem xyuam, tau siv dav hauv kev ua npuas ncauj rwb thaiv tsev rau cov tsev thiab cov khoom siv, nrog rau hauv cov txheej txheem vaj tsev.
Automotive sector siv cov thermoplastics ntau zuj zus, feem ntau los txo qhov hnyav thiab yog li ua tiav cov qauv siv roj ntau dua.Cov European Union kwv yees tias 16% ntawm qhov hnyav ntawm lub tsheb nruab nrab yog cov khoom siv yas, tshwj xeeb tshaj yog rau cov khoom siv sab hauv thiab cov khoom siv.
Tshaj li 70 lab tons ntawm thermoplastics ib xyoos twg yog siv rau hauv textiles, feem ntau yog khaub ncaws thiab ntaub pua plag.Ntau tshaj 90% ntawm cov hluavtaws fibers, feem ntau polyethylene terephthalate, yog tsim nyob rau hauv Asia.Kev loj hlob ntawm kev siv fiber ntau hauv cov khaub ncaws tau los ntawm kev siv cov fibers ntuj xws li paj rwb thiab ntaub plaub, uas yuav tsum muaj ntau qhov chaw ua liaj ua teb los tsim.Kev lag luam hluavtaws fiber ntau tau pom kev loj hlob ntawm cov khaub ncaws thiab ntaub pua plag, ua tsaug rau kev txaus siab rau cov khoom tshwj xeeb xws li ncab, ya raws-wicking, thiab breathability.
Raws li nyob rau hauv cov ntaub ntawv ntawm ntim, textiles tsis nquag siv dua.Cov pej xeem Asmeskas nruab nrab tsim ntau dua 90 phaus ntawm cov ntaub ntawv pov tseg txhua xyoo.Raws li Greenpeace, tus neeg nruab nrab hauv 2016 yuav 60% ntau cov khaub ncaws txhua xyoo ntau dua li tus neeg nruab nrab tau ua 15 xyoo dhau los, thiab khaws cov khaub ncaws rau lub sijhawm luv.
Post lub sij hawm: Jul-03-2023