Polyethylene: melting point, neeg zog thiab daim ntawv thov

Niaj hnub no, tib neeg yuav tsis ua li cas tsis dag cov ntaub ntawv. Lawv muaj ib tug xov tooj ntawm cov cim qualities muaj thiab txo tus nqi ntawm ntau lawm. Ib tug xws li cov ntaub ntawv uas ua raws li polyethylene. Lub melting point, raws li zoo li lwm yam specifications yog ncauj lus kom ntxaws tsim nyog saib xyuas. Nws yog ib tug ntawm cov feem ntau sought-tom qab cov ntaub ntawv niaj hnub no. Tsis tas li ntawd, cov tshuaj kev lag luam ntiaj teb no ua ib nrab ntawm cov ethylene, yog raws kev coj kom qhov kev npaj ntawm polyethylene. Yuav kom to taub yog vim li cas nws yog li ntawd nrov hnub no, koj yuav tsum xav txog nws tus yam ntxwv.

Yuav ua li cas yog lub substance

Tus qauv ntawm lub polyethylene molecules yog heev yooj yim. Nws zoo li ib cov saw uas muaj cov pa roj carbon atoms. Mus rau txhua lub ntawm lawv koom nrog ob molecules ntawm hydrogen. Nyob rau hauv lub ntiaj teb no muaj ob versions ntawm no substance. Lawv txawv nyob rau hauv cov qauv. Qhov no yog thaws rov los nyob rau hauv cov khoom muaj los ntawm polyethylene (a melting thiab kub taw tes, neeg). Yuav ua li cas koom siab ua ke rau lawv tsuas yog lub keeb kwm. Ob leeg hloov yog npaj los ntawm ethylene.

Tus thawj hom muaj linear polyethylene monomers. Lawv degree ntawm polymerization yog 5000 los yog ntau tshaj. Qhov thib ob hloov muaj ib tug branching monomers. Lawv muaj li ntawm cov pa roj carbon atoms (4 mus rau 6).

Yuav kom tsim tau ib tug linear polyethylene, siv tej catalysts. Lub polymerization txheej txheem tshwm sim nyob rau kub txog li 150 ° C.

yam ntxwv ntawm

Lub thermoplastic polymer uas yog yus muaj los ntawm ib tug opacity ntawm txheej nyob rau tuab, zoo nkaus li rau peb polyethylene. Melting point, kev yam ntxwv ntawm cov khoom ua nws ib tug nrov xaiv. Nws crystallizes nyob rau hauv ntau ntawm -60 mus -269 ° C.

Nws lub ntsiab zoo zoo yog tus tsis muaj tso zis ntawm polyethylene. Nyob rau hauv tsev, nws yuav tsis raug rau ib tug ntau yam ntawm cov organic solvents. Tsis tas li ntawd, nws tsis hnov mob hauv chav tsev kub rau ntsev dej, acidic thiab alkaline daws teeb meem.

Thaum lub kub nce mus rau 60 ° C, cov khoom yuav lam tau lam ua rau sulfuric thiab nitric acids. Thov oxidants los kho tus mob ntawm qhov chaw ntawm polyethylene, yuav tsum puas tsuaj ntawm tus nto txheej. Cov khoom pib yuav tsum tau wetted nrog dej. Qhov no zoo tsim nyog rau tsevneeg polyethylene.

polymerization txoj kev

Nyob rau cov qauv ntawm cov polymerization ntawm ethylene, polyethylene yog 3 hom: tsawg, loj siab thiab linear hom khoom. Nws txiav txim li cas qualities yuav muaj ib tug polyethylene. Lub melting point, cov kev zog ntawm txhua tus tsiaj txawv. Yog li ntawd, lawv yog siv nyob rau hauv txhua cheeb ntawm tib neeg kev ua si.

Polyethylene yog ua nyob rau hauv kub siab, ntau mos mos. Nws polymerized radical txoj kev. Lub siab ntawm no achieves 1-3 txhiab. ATM. Qhov kub yog 180 ° C. Pa yog muab kev koom tes nyob rau hauv cov ntaub ntawv no raws li lub initiator.

Tsis tshua muaj ceev polyethylene yog manufactured siv Ziegler-Natta catalysts. Nyob rau hauv tus txheej txheem no kuj yuav siv sij hawm yog ib feem organic kuab. Kev khiav hauj lwm siab yog tsawg kawg yog 5 atm., Thiab qhov kub thiab txias tshaj 80 ° C.

Tawm (nruab nrab) polyethylene yog ib nrab cov ntaub ntawv uas nyob nruab nrab ntawm qhov suav hais tias hom. Qhov no siv rau cov qualities thiab zog. Nws yog tsim los ntawm ib tug siab ntawm 30-40 atm. Thaum uas siv cov metallocene catalysts yog tau mus nrhiav tau ib yam khoom ntawm kho kom zoo zog.

Yog vim li cas rau qhov sib txawv Polyethylene khoom

Branching macromolecular qauv txiav txim cov khoom muaj los ntawm polyethylene. Lub melting point, ceev, nyob ntawm seb lub hom Circuit Court. Qhov ntau ceg nws muaj, qhov ntau elastic cov ntaub ntawv uas muaj tsawg crystalline zog yog tau nyob rau hauv lub tso zis.

Qhov no feature hinders lub tsim ntawm cov qauv denser ntim macromolecules chaw khuam siab yuav 100% ntawm cov theem ntawm crystallinity. Cov khoom kuj muaj ib qho atmospheric theem. Nws muaj txaus kom cov hlob thiab cov molecules. Cov raug txoj kev txiav txim seb tus piv ntawm crystalline thiab atmospheric theem. Qhov no feature muaj feem xyuam rau lub zog ntawm cov polyethylene.

Yog li ntawd, cov zaj duab xis, uas tsawg-siab, ntau permeable tshaj lwm hom. Qhov ntau dua qhov crystallinity (molecular yuag), lub siab dua txhua yam kev ua tau zoo. Yog li ntawd, raws li ib tug zaj duab xis cov ntaub ntawv uas yog pob tshab thiab ywj. Txawm li cas los, polyethylene nplooj ntawv yog txhav thiab opaque.

cov teebmeem ntawm kub

Nyob rau hauv tus ntawm ib puag ncig zoo hloov, uas yog muab tej txiaj ntsim nrog polyethylene. Lub melting point ntawm no substance yog tseem nyob rau cov qauv ntawm cov ntau lawm. Nyob rau hauv dav dav, lub polyethylene thaum rhuab undergoes ob peb theem. Ua ntej, nws yuav ib tug mos mos, elastic. Nws yog yooj yim deformed los ntawm cov neeg kho tshuab pa.

Brittleness kub uas tus nruab nrab loses nws lub zog polyethylene yam ntxwv yog 70 ° C. Nrog ntxiv rau kom nws cov khoom softens ntau. Nws kiag li loses nws xam qhovkev zoo thaum rhuab saum toj no 120 ° C. Nyob rau hauv tshuaj nws puv kua ib tug kub ntawm 130 ° C.

Nyob rau hauv tas li ntawd mus rau lub cua sov kub, nws yog tsim nyog los noj mus rau hauv tus account lub feem ntawm ultraviolet tawg. Yog hais tias cov ntaub ntawv uas yog siv rau sab nraum zoov cov khoom, koj yuav tsum xaiv ib tug muaj zog ntau yam. Txwv tsis pub, cov mos mos, elastic polyethylene tom qab xyoo ntawm lub lag luam nyob rau hauv ncaj qha tshav ntuj yuav ua nyuaj thiab nkig. Txawm cov xim ntawm cov khoom hloov lub sij hawm.

High ceev polyethylene

Txhua ntau yam ntawm cov ntaub ntawv uas, muaj tshwj xeeb qualities. Qhov no ncua lub ntau yam ntawm daim ntawv sau npe, uas muaj polyethylene. Melting point (kev kub ceev) yog 120-135 ° C. Nyob rau hauv ib co qib ntawm tshav kub kuj yog 110 ° C. High molecular ceev pab txoj kev thermal thiab poob siab kuj.

Nyob rau hauv tas li ntawd mus rau cov qualities, tsis tshua muaj ceev polyethylene yog tsawg raug tshuaj nres. Txawm li cas los, ntau ceev ntawm molecules thaum uas tsis muaj kub, ua cov ntaub ntawv uas nkig, nws yuav permeable rau pa, gases.

Qhov no zoo ntawm cov ntaub ntawv uas muaj zoo dielectric yam ntxwv. Nws yog biologically tsaug zog tab sis yog yooj yim ua rau hauv industrial qhuav.

Tsis tshua muaj ceev polyethylene

Qhov no pab pawg neeg no muaj xws li ib tug saj zawg zog, khaub-ncaws nyias polyethylene. Melting kub, crystallization zog tsis pub nws los ntawm high-zog, Thaum tshav kub kub-resistant cov khoom. Nyob ntawm seb lub hom yuav muaj ib tug txawv ceev. Lawv melting kub yog los ntawm 60 mus rau 90 ° C.

Ib yam li yav dhau los hom ntawm cov khoom, high-ceev polyethylene yog check ntau, yog hais tias ib tug molecular yuag tsub kom. Nws yog tsawg nws tshuaj, ultraviolet influences. Tab sis nws thiaj li nws muaj peev xwm los mus tiv shocks. Nyob rau qhov no polyethylene nyob rau hauv mob loj heev te tej kab nrib pleb, lov. Nws yuav permeable rau vapors thiab roj cua.

Xws li ib tug cov ntaub ntawv uas tseem yog tam sim no zoo dielectric qualities. Nws tsis qhia kuj mus rog, roj. Tab sis qhov no cov ntaub ntawv uas yog tau muaj cov tawg kab teeb. Biologically, qhov no cov ntaub ntawv uas tseem yog inert, tab sis yooj yim rau ua.

Siv tsawg-density polyethylene

Txiav txim lub xam qhovkev zoo cov ntaub ntawv uas tau txais uas yog polyethylene. Melting point (qhov kev siv ntawm no parameter yog yuav tsum tau thaum xaiv txhua yam khoom) enables txiav txim siab ntawm xws li ib tug tshuaj ntim thiab ntim. Nyob rau hauv feem ntau tus neeg mob, lub thawv yog manufactured los ntawm tshuab molding. Cov no tej zaum yuav ntim rau tshuaj pleev ib ce los yog perfumes, khoom noj khoom haus ntim.

Cov kos poom thiab thawv los ntawm ib tug tsawg-density polyethylene siv nyob rau hauv lub tsheb thiab tshuaj kev lag luam, nyob rau hauv qhov siv thiab ua cov roj tso tsheb hlau luam thiab drums.

Nkag mus rau hauv kom zus tau tej cov ntim films ntawm tib cov ntaub ntawv uas. Nws yog dav siv nyob rau hauv qhuav ntawm cov kav dej, yeeb nkab fittings. Nws yog ib tug pheej yig thiab check khoom. Nws yog tau tshem Rau ntxiv kev sib tw cov khoom los ntawm kev ua lag luam.

Daim ntawv thov ntawm high-density polyethylene

Polyethylene, uas yog hauv qab no lub melting kub tshaj yav dhau los hom, yog siv nyob rau hauv qhuav ntawm films rau ua liaj ua teb, lag luam ua noj thiab lwm yam kev cov hom phiaj. Nws thov yog tas li loj hlob.

Ntau films rau ua liaj ua teb lub hom phiaj yuav muaj ib tug ntxiv qhov cuab lub zog, cov xim yog kuj sib txawv. Lawv yog siv nyob rau hauv greenhouses, liaj teb los txhim kho qhov zoo thiab muaj nuj nqis ntawm cov qoob loo.

Khoom noj khoom haus films, tej pob khoom tag nrho cov thoob lub ntiaj teb no yog noj nrog rau txhua yam nyob rau hauv ib tug loj scale txhua txhua xyoo. Qhov no hom ntawm cov ntaub ntawv uas yog ousted los ntawm lub ntsiab kev ua lag luam theem khoom los ntawm lwm yam ntaub ntawv.

qauv ntawm kev noj

Polyethylene, melting point uas txhais nws uas thoob ntiaj teb nyob rau hauv zoo kawg thov. Tus qauv ntawm cov ntaub ntawv uas noj yog heev nthuav. 60-70% ntawm polyethylene siv los tsim cov ntawv txheeb thiab films.

Tsis tas li ntawd, ib tug loj ib feem ntawm tag nrho cov zis nyob rau hauv lub khoom tau los ntawm kev txhaj tshuaj molding los yog los ntawm txoj kev extrusion. Me ntsis ntau tshaj li qhov ntau lawm ntawm rwb thaiv tsev rau hluav taws xob nyob ntawm tej, kav thiab fittings. polyethylene kuj yog siv rau cov khoom los ntawm tshuab molding, thiab lwm tus neeg.

Nyob rau hauv zus tau tej cov ntawv txheeb thiab films yog yuav luag ib txwm siv kev kub siab polyethylene (tsawg ceev). Lawv manufactured nyob rau hauv ntau txoj kev. Tus zaj duab xis thickness yog nyob rau hauv ntau 0.03-0.3 hli, thiab cov nplooj ntawv - 6.1 hli.

Nyob rau hauv tas li ntawd mus ntim, muaj ib tug cov ntaub ntawv uas tej zaum yuav ua sacks, hnab, hnab twb qhib lawm rau drawers, thawv thiab lwm yam ntim. Cov khoom yuav tsum tau ntawm cov khoom, txiav txim rau txoj kev ntawm zus tau tej cov polyethylene. Qhov kawg ntawm ntau lawm ntawm txhua yam ntawm cov ntaub ntawv uas yog muab vintage. Nws yuav pab tau xaiv txoj cai zoo ntawm cov ntaub ntawv uas rau tej kev lag luam.