Tam sim no, cov khoom siv PVC tau siv dav hauv ntau yam khoom siv hauv tsev, tab sis qhov xav tau tom qab yog cov khoom siv PVC muaj cov nplaim hluav taws zoo. Txawm li cas los xij, nyob rau hauv cov txheej txheem tsim khoom ntawm PVC, txhawm rau txhim kho nws cov kev ua tau zoo thiab txo cov nqi, nws yuav ntxiv ib qho nyiaj ntawm plasticizer. Keeb kwm, PVC raw khoom resin muaj qee yam nplaim taws-retardant khoom, tab sis yog tias cov yas tsis raug xaiv kom raug, nws yuav txo tau cov nplaim hluav taws kub ntawm cov khoom siv PVC. Dab tsi yog qhov tseem ceeb ntawm cov nplaim hluav taws kub-retardant plasticizers?
▶ Nplaim-retardant plasticizer
Feem ntau, plasticizers nrog cov pa ntsuas ntau dua 28 yog suav tias yog nplaim hluav taws. Tam sim no cov yas siv dav siv nrog cov nplaim hluav taws xob muaj xws li phosphate esters, chlorinated paraffin thiab chlorinated fatty acid esters:
1. Phosphate esters: Lub ntsiab feature ntawm phosphate ester plasticizers yog tias lawv muaj cov nplaim taws retardancy thiab tau dav siv los ua plasticizers rau PVC thiab cellulose.
2. Chlorinated paraffin: Chlorinated paraffin kuj pheej yig thiab siv ntau ntau li cov khoom siv yas. Kev ua haujlwm ntawm chlorinated paraffin yog ze ze rau cov ntsiab lus chlorine. Nrog rau qhov nce ntawm cov ntsiab lus chlorine, cov nplaim hluav taws kub hnyiab tau zoo dua qub, tab sis qhov kev tiv thaiv txias yuav hnyav dua, yog li nws yog siv los ua plasticizer Chlorinated paraffin feem ntau muaj 40-50% chlorine.
3. Chlorinated fatty acid esters: Piv txwv li, methyl pentachlorostearate, vim hais tias muaj ib pab pawg ester nyob rau hauv cov molecule, cov compatibility nrog PVC yog zoo dua li cov chlorinated paraffin. Thaum siv ua ke nrog antimony trioxide, cov nplaim retardant nyhuv ntawm cov tshuaj chlorine uas muaj cov yas yas tuaj yeem ua tiav tag nrho.
▶ Peb yam hauv qab no cuam tshuam cov nplaim hluav taws xob ntawm cov yas yas:
Ua ntej, nws nyob ntawm qhov volatility ntawm plasticizer txheeb ze rau PVC. Qhov ntau dua qhov volatility, qhov phem qhov nplaim retardancy;
Qhov thib ob, nws nyob ntawm cov khoom decomposition uas tsim thaum lub sij hawm combustion, uas tsis yog nplaim taws retardants;
Thib peb, nws nyob ntawm cov qauv tshuaj ntawm cov plasticizer. Txhua lub plasticizer uas muaj phosphorus, chlorine, thiab aryl pawg muaj cov nplaim hluav taws zoo dua.