PVC yas khoom

Lub combustion yam ntxwv ntawm PVC yog tias nws yog ib qho nyuaj rau hlawv, tua tam sim ntawd tom qab tawm hauv hluav taws, cov nplaim yog daj thiab dawb cov pa luam yeeb, thiab cov yas softens thaum hlawv, muab tawm lub irritating tsw ntawm chlorine.

Polyvinyl chloride resin yog cov khoom siv ntau yam yas.Cov khoom sib txawv tuaj yeem muab ntxiv raws li kev siv sib txawv.Yog li ntawd, nrog kev sib xyaw sib txawv, nws cov khoom tuaj yeem pom cov khoom sib txawv ntawm lub cev thiab cov khoom siv kho tshuab.Piv txwv li, nws tuaj yeem muab faib ua cov khoom muag muag thiab tawv nrog lossis tsis muaj plasticizer.Feem ntau, cov khoom siv PVC muaj qhov zoo ntawm cov tshuaj lom neeg ruaj khov, nplaim taws ua haujlwm thiab tua tus kheej, hnav tsis kam, suab nrov thiab kev co tshem tawm, siab zog, zoo hluav taws xob rwb thaiv tsev, tsis tshua muaj nqi, khoom siv dav, huab cua zoo, thiab lwm yam. Nws qhov tsis zoo yog qhov tsis zoo. thermal stability thiab kev laus yooj yim nyob rau hauv qhov kev txiav txim ntawm lub teeb, tshav kub thiab oxygen.PVC resin nws tus kheej yog non-toxic.Yog tias cov khoom ua los ntawm cov yas tsis muaj tshuaj lom, cov khoom siv ruaj khov thiab lwm yam khoom siv tau siv, lawv tsis muaj mob rau tib neeg thiab tsiaj txhu.Txawm li cas los xij, feem ntau ntawm cov plasticizers thiab stabilizers siv hauv PVC cov khoom feem ntau pom hauv khw yog tshuaj lom.Yog li ntawd, tshwj tsis yog rau cov khoom uas tsis muaj tshuaj lom, lawv tsis tuaj yeem siv kom muaj cov khoom noj.

1. Kev ua tau zoo ntawm lub cev

PVC cob yog cov thermoplastic nrog amorphous qauv.Nyob rau hauv lub teeb ultraviolet, tawv PVC ua lub teeb xiav lossis ntshav dawb fluorescence, thaum mos PVC emits xiav lossis xiav dawb fluorescence.Thaum qhov kub thiab txias yog 20 ℃, qhov refractive index yog 1.544 thiab lub ntiajteb txawj nqus tshwj xeeb yog 1.40.Qhov ntom ntawm cov khoom siv nrog cov yas thiab muab tub lim yog feem ntau nyob rau hauv thaj tsam ntawm 1.15 ~ 2.00, qhov ceev ntawm cov mos PVC ua npuas ncauj yog 0.08 ~ 0.48, thiab qhov ceev ntawm cov npuas tawv tawv yog 0.03 ~ 0.08.Kev nqus dej ntawm PVC yuav tsum tsis txhob ntau tshaj 0.5%.

Lub cev thiab txhua yam khoom ntawm PVC nyob ntawm qhov hnyav molecular ntawm resin, cov ntsiab lus ntawm plasticizer thiab muab tub lim.Qhov siab dua qhov hnyav molecular ntawm cov resin, qhov siab dua cov khoom siv kho tshuab, txias tsis kam thiab thermal stability, tab sis cov txheej txheem kub kuj yuav tsum tau siab, yog li nws yog ib qho nyuaj rau tsim;Tsawg molecular hnyav yog qhov txawv ntawm cov saum toj no.Nrog rau qhov nce ntawm cov ntsiab lus muab tub lim, lub zog tensile txo.

2. Kev ua haujlwm kub

Lub softening point ntawm PVC resin yog ze rau qhov decomposition kub.Nws tau pib decompose ntawm 140 ℃, thiab decomposes sai dua ntawm 170 ℃.Txhawm rau kom ntseeg tau tias cov txheej txheem molding ib txwm muaj, ob qho tseem ceeb tshaj plaws cov txheej txheem qhia rau PVC cob tau teev tseg, uas yog decomposition kub thiab thermal stability.Qhov hu ua decomposition kub yog qhov kub thiab txias thaum tso tawm ntau ntawm hydrogen chloride, thiab qhov hu ua thermal stability yog lub sij hawm thaum muaj ntau cov hydrogen chloride tsis tso tawm nyob rau hauv tej yam kub thiab txias (feem ntau yog 190 ℃).PVC yas yuav decompose yog tias nws raug rau 100 ℃ ntev, tshwj tsis yog alkaline stabilizer ntxiv.Yog tias nws siab tshaj 180 ℃, nws yuav decompose sai.

Kev siv mus sij hawm ntev ntawm cov khoom siv PVC feem ntau yuav tsum tsis txhob siab tshaj 55 ℃, tab sis lub sij hawm siv ntev ntawm PVC yas nrog cov mis tshwj xeeb tuaj yeem ncav cuag 90 ℃.Cov khoom muag PVC yuav ua rau tawv nqaij ntawm qhov kub thiab txias.PVC molecules muaj cov tshuaj chlorine atoms, yog li nws thiab nws cov copolymers feem ntau yog nplaim taws tiv taus, nws tus kheej tua thiab tsis muaj dej.

3. Kev ruaj ntseg

Polyvinyl chloride resin yog ib qho tsis ruaj khov polymer, uas tseem yuav degrade nyob rau hauv qhov kev txiav txim ntawm lub teeb thiab kub.Nws cov txheej txheem yog tso tawm hydrogen chloride thiab hloov nws cov qauv, tab sis kom tsawg dua.Nyob rau tib lub sij hawm, lub decomposition yuav ceev nyob rau hauv lub xub ntiag ntawm mechanical quab yuam, oxygen, tsw, HCl thiab ib co active hlau ions.

Tom qab tshem HCl los ntawm PVC cob, conjugated ob chains yog tsim nyob rau hauv lub ntsiab saw, thiab cov xim kuj yuav hloov.Raws li tus nqi ntawm hydrogen chloride decomposition nce, PVC resin hloov ntawm dawb mus rau daj, sawv, liab, xim av thiab txawm dub.

4. Kev ua haujlwm hluav taws xob

Cov khoom hluav taws xob ntawm PVC nyob ntawm seb cov khoom seem hauv cov polymer thiab hom thiab ntau npaum li cas ntawm cov khoom ntxiv hauv cov mis.Cov khoom hluav taws xob ntawm PVC kuj muaj feem xyuam rau cov cua sov: thaum cua sov ua rau PVC decompose, nws cov hluav taws xob rwb thaiv tsev yuav raug txo vim muaj cov chloride ions.Yog tias muaj ntau cov tshuaj chloride ions tsis tuaj yeem nruab nrab los ntawm alkaline stabilizers (xws li cov ntsev ntsev), lawv cov hluav taws xob rwb thaiv tsev yuav raug txo kom tsawg.Tsis zoo li cov polymers uas tsis yog-polar xws li polyethylene thiab polypropylene, PVC cov khoom hluav taws xob hloov nrog zaus thiab kub, piv txwv li, nws cov dielectric tsis tu ncua txo nrog qhov nce ntawm zaus.

5. Cov khoom siv tshuaj

PVC muaj kev ruaj ntseg zoo heev thiab muaj txiaj ntsig zoo li cov khoom siv tiv thaiv corrosion.

PVC ruaj khov rau feem ntau inorganic acids thiab hauv paus.Nws yuav tsis yaj thaum rhuab thiab yuav decomposed kom tso hydrogen chloride.Ib qho xim av insoluble unsaturated khoom tau npaj los ntawm azeotropy nrog potassium hydroxide.Lub solubility ntawm PVC muaj feem xyuam rau molecular hnyav thiab txoj kev polymerization.Feem ntau hais lus, cov solubility txo qis nrog qhov nce ntawm cov khoom siv polymer molecular hnyav, thiab solubility ntawm cov tshuaj pleev ib ce yog qhov phem dua li ntawm cov khoom ncua kev kawm.Nws tuaj yeem yaj hauv ketones (xws li cyclohexanone, cyclohexanone), cov kuab tshuaj tsw qab (xws li toluene, xylene), dimethylformyl, tetrahydrofuran.PVC resin yuav luag insoluble nyob rau hauv plasticizers nyob rau hauv chav tsev kub, thiab ho swells los yog txawm yaj nyob rau hauv high kub.

⒍ processability

PVC yog ib qho amorphous polymer uas tsis muaj qhov pom tseeb melting point.Nws yog yas thaum rhuab mus rau 120 ~ 150 ℃.Vim nws tsis zoo thermal stability, nws muaj ib tug me me ntawm HCl ntawm qhov kub thiab txias, uas txhawb nws ntxiv decomposition.Yog li ntawd, alkaline stabilizer thiab HCl yuav tsum tau ntxiv rau inhibit nws cov catalytic cracking cov tshuaj tiv thaiv.Pure PVC yog ib qho khoom siv tawv, uas yuav tsum tau ntxiv nrog rau qhov tsim nyog ntawm cov yas yas kom nws mos.Rau cov khoom sib txawv, cov khoom siv ntxiv xws li UV absorbers, fillers, lubricants, pigments, anti mildew agents thiab lwm yam yuav tsum tau ntxiv los txhim kho kev ua tau zoo ntawm cov khoom PVC.Zoo li lwm yam plastics, cov khoom ntawm resin txiav txim siab qhov zoo thiab kev ua haujlwm ntawm cov khoom.Rau PVC, cov khoom muaj feem cuam tshuam nrog kev ua haujlwm suav nrog qhov loj me, thermal stability, molecular hnyav, ntses qhov muag, qhov ntom ntom, purity, txawv teb chaws impurities thiab porosity.Lub viscosity thiab gelatinization cov khoom ntawm PVC muab tshuaj txhuam, muab tshuaj txhuam, thiab lwm yam yuav tsum tau txiav txim siab, thiaj li ua tau raws li kev ua haujlwm thiab cov khoom zoo.