Kev tsiv teb tsaws chaw thiab nthuav tawm cov yas hauv PVC cov khoom tuaj yeem ua rau daj, tawv, thiab tawg ntawm cov khoom, uas yuav cuam tshuam rau kev ua haujlwm ntawm cov khoom. Dab tsi' qhov hnyav dua yog qhov ntau tshaj ntawm phthalate esters (PAEs) cov yas muaj peev xwm ua rau muaj mob qog noj ntshav, thiab lawv yuav tsim kev phom sij rau tib neeg kev noj qab haus huv thiab ua paug ib puag ncig tom qab lawv tawm ntawm cov khoom PVC. Yog li ntawd, kawm txog cov txheej txheem kev tsiv teb tsaws chaw thiab kev tiv thaiv txheej txheem ntawm cov yas hauv PVC cov khoom lag luam yog qhov tseem ceeb heev rau kev txwv tsis pub muaj kev tsiv teb tsaws chaw thiab tsim cov khoom lag luam uas tsis yog txav chaw ntawm PVC.
1. Kev txav chaw ntawm cov yas yas
Lub zog nruab nrab ntawm cov yas thiab PVC cov lwg me me tsis muaj zog van der Waals quab yuam thiab hydrogen sib cog, thiab cov yas yooj yim txav mus los thiab kis mus rau sab nraud thaum ua haujlwm thiab siv.
Muaj plaub txoj hauv kev tseem ceeb ntawm kev tsiv teb tsaws chaw thiab nthuav tawm cov yas yas:
OlVolatilize los ntawm cov khoom siv PVC mus rau huab cua;
② Cov kua theem hu los ntawm PVC cov khoom tau muab rho tawm;
③ Kev tsiv teb tsaws chaw thiab kev nthuav tawm tshwm sim hauv cov khoom lossis ib nrab khoom tiv tauj los ntawm PVC cov khoom;
XExuded los ntawm cov khoom PVC hauv siab.
Kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas yas feem ntau mus dhau peb theem: cov yas yas nthuav tawm mus rau sab hauv, ua rau&"rov qab ua haujlwm &"; xeev nyob rau sab hauv sab hauv, thiab nthuav tawm deb ntawm cov khoom.
Kev tsiv teb tsaws chaw thiab kev nthuav tawm ntawm cov yas tuaj yeem suav hais tias yog kev hloov pauv ntawm cov tshuaj me me hauv cov polymer, uas yog kev tsiv teb tsaws chaw ntawm qhov sib txawv ntawm ntu polymer. Polymer molecular saw ntu feem ntau suav nrog cov kab, cov ceg ntoo thiab hom sib txuas sib txuas, thiab yuav muaj kev npaj thiab teeb tsa ntawm cov saw ntu. Yog li ntawd, kev teeb tsa sab hauv txheej txheem txheej txheem ntawm cov polymer yog qhov nyuaj heev, thiab muaj thaj chaw muaj kuab zoo nkauj thiab tsis zoo ib yam. Cov cheeb tsam Amorphous feem ntau yog amorphous, nrog ntau qhov khoob ntawm ntu ntau dua li thaj chaw crystalline. Yog li ntawd, kev tsiv teb tsaws chaw thiab kev nthuav tawm ntawm cov molecules me me hauv thaj chaw crystalline yog qis dua li ntawm thaj av amorphous. Cov morphology ntawm thaj chaw siv lead ua, thaj chaw amorphous, thiab ntu ntu molecular yuav hloov pauv nrog kev hloov pauv ntawm lwm qhov xwm txheej xws li kub.
2. Yam cuam tshuam rau kev tsiv teb tsaws chaw yas
Lub hauv paus tseem ceeb cuam tshuam rau kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas hauv PVC cov khoom yog qhov kub, PVC cov yam ntxwv khoom, cov yam ntxwv yas yas, cov ntsiab lus yas, nruab nrab, thiab lwm yam.
① Kub: Qhov ntsuas kub tuaj yeem cuam tshuam qhov tshwm sim ntawm kev nthuav tawm. Qhov kub siab dua, ntau dua cov cua sov ua kom muaj zog ntawm atoms, thiab kev txav chaw yooj yim dua yuav tshwm sim.
CharacteristicsPVC cov yam ntxwv ntawm cov khoom: feem ntau cuam tshuam hauv qhov ntim dawb ntawm ntu saw thiab cov yam ntxwv txav ntawm cov saw saw. Thaum qhov ntim tsawg kawg uas yuav tsum tau ua rau kev txav ntawm cov yas yas yas tsawg dua li qhov ntim dawb ntawm ntu ntu polymer, cov yas yas tuaj yeem nthuav tawm los ntawm cov ntu polymer. Qhov ntau dua qhov ntim dawb hauv PVC, nws yooj yim dua rau cov yas yas lwg me me kom txav mus los. Qhov siab dua qib ntawm kev tsis txaus ntseeg ntawm PVC cov saw hlau, muaj zog txav mus los thiab yooj yim dua cov yas yas kom nthuav dav.
Characteristics Cov yam ntxwv ntawm cov yas: cov txheeb ze hnyav hnyav ntawm cov yas yas cuam tshuam ncaj qha rau nws lub peev xwm tsiv teb tsaws chaw. Qhov loj dua tus txheeb ze hnyav hnyav, qhov nyuaj dua nws yog nthuav tawm hauv PVC cov khoom. Thaum cov yas yas ntim khoom ntim zoo ib yam, cov yas yas nrog lub tiaj lossis ntev cov lwg me me yooj yim dua rau kis dua li cov yas yas nrog cov qauv kheej kheej.
ContentPlasticizer cov ntsiab lus: thaum lwm yam xwm txheej zoo ib yam, ntau dua cov ntsiab lus yas yas, kev txav chaw yooj yim dua yuav tshwm sim.
EdMedium: Feem ntau hais lus, cov yas yas yooj yim dua los ntawm cov roj theem hnyav, tab sis nyuaj rau rub tawm los ntawm theem dej.