Yog vim li cas vim li cas polyvinyl chloride (PVC) additives tuaj yeem txhim kho kev ua haujlwm zoo, cov khoom siv kho tshuab, thiab cov khoom siv ua haujlwm ntev ntawm cov resin nyob hauv qhov sib txawv thiab muaj txiaj ntsig zoo ntawm lawv cov tshuaj muaj pes tsawg leeg.Chemical muaj pes tsawg leeg tsis tsuas yog txiav txim siab txog lub hauv paus physicochemical thaj chaw ntawm additives tab sis kuj ncaj qha cuam tshuam rau lawv cov compatibility, stability, thiab kev ua haujlwm ntawm PVC systems. Los ntawm cov tshuaj muaj pes tsawg leeg pom, PVC additives tuaj yeem muab faib ua cov hlau sib txuas, cov organic acids thiab lawv cov derivatives, siab molecular polymers, inorganic minerals, thiab composite functional additives. Txhua hom kev tivthaiv muaj nws tus kheej cov qauv molecular thiab mechanism ntawm kev ua.
Cov khoom siv hlau yog cov khoom tseem ceeb ntawm cov cua sov stabilizers, thiab cov piv txwv zoo xws li calcium stearate, zinc stearate, dibutyltin dilaurate, thiab dibutyltin maleate. Stearates, tsim los ntawm ntev - chain fatty acid ions thiab alkaline ntiaj teb los yog kev hloov hlau ions, tuaj yeem cuam tshuam cov hydrogen chloride tsim thaum lub sij hawm thermal decomposition ntawm PVC, inhibiting cov saw degradation cov tshuaj tiv thaiv. Organotin compounds, ntawm qhov tod tes, koom tes nrog cov tshuaj chlorine tsis ruaj khov hauv PVC molecular saw ntawm Sn-O lossis Sn-S bonds, tiv thaiv dehydrochlorination. Qhov sib txawv ntawm lub vojvoog ionic, kev sib koom tes muaj peev xwm, thiab thermal stability ntawm cov hlau sib txawv ua rau muaj kev sib txawv loj hauv kev ua tau zoo, huab cua tsis kam, thiab kev phooj ywg ib puag ncig ntawm ntau cov hlau sib txuas.
Organic acids thiab lawv cov derivatives tuav txoj haujlwm tseem ceeb hauv plasticizers, lubricants, thiab qee qhov stabilizers. Phthalate esters (xws li dioctyl phthalate, DOP), citrate esters (xws li tributyl acetylacetonate, ATBC), thiab epoxidized soybean roj nyob rau hauv pawg no. Lawv cov qauv molecular feem ntau muaj xws li cov polar functional pawg (ester, carboxyl, epoxy pawg) thiab nonpolar ntev carbon chains. Cov polar feem muab kev sib raug zoo nrog PVC, thaum cov ntu uas tsis yog-polar cuam tshuam kev hloov pauv thiab kev tswj kev tsiv teb tsaws chaw. Tus naj npawb ntawm ester bonds, saw ntev, thiab℃ntawm branching nyob rau hauv ib tug tshuaj muaj pes tsawg leeg txiav txim siab plasticizing efficiency, qis - kub ua hauj lwm, thiab volatility kuj.
Cov khoom hnyav molecular polymers feem ntau yog siv los ua cov kev hloov pauv thiab kev ua haujlwm, xws li acrylate copolymer (ACR), methyl methacrylate-butadiene-styrene copolymer (MBS), thiab chlorinated polyethylene (CPE). Cov polymers no yog tsim los ntawm txawv monomer units txuas los ntawm covalent bonds, ua ib tug tub ntxhais -plhaub los yog interpenetrating network qauv. Qhov sib txawv ntawm cov tshuaj muaj pes tsawg leeg txiav txim siab lawv kev sib raug zoo nrog PVC matrix, dispersion morphology, thiab toughening mechanism. Piv txwv li, ntu butadiene hauv MBS muab elasticity, thaum methyl methacrylate ntu txhim kho kev sib txuas ntawm lub ntsej muag nrog PVC.
Inorganic ntxhia additives, suav nrog txhuas hydroxide, magnesium hydroxide, talc, calcium carbonate, thiab zinc borate, feem ntau yog siv rau cov nplaim hluav taws kub hnyiab, hluav taws kub hnyiab, thiab kev hloov kho. Lawv cov tshuaj muaj pes tsawg leeg yog tsim los ntawm cov hlau oxides, hydroxides, los yog cov ntsev inorganic, ua rau muaj kev kub ntxhov thiab tshuaj lom neeg ruaj khov. Nyob rau hauv cov cua kub los yog combustion tej yam kev mob, cov tebchaw ua tau nplaim retardancy thiab pa luam yeeb ua haujlwm los ntawm endothermic decomposition, tso dej vapor, los yog tsim ib tug barrier txheej. Cov hom hlau ntsiab lus, dej ntawm crystallization cov ntsiab lus, thiab particle loj tis nyob rau hauv ib tug tshuaj muaj pes tsawg leeg ncaj qha cuam tshuam rau nws cov nplaim retardant efficiency thiab nws cuam tshuam rau lub mechanical zog ntawm PVC.
Composite functional additives ua kom muaj kev sib koom ua ke los ntawm kev tshawb fawb sib xyaw ntawm ntau yam tshuaj lom neeg. Piv txwv li, calcium -zinc composite stabilizers muaj calcium stearate, zinc stearate, thiab auxiliary stabilizing Cheebtsam (xws li hydrotalcite thiab -diketone). Cov kua qaub-piv nruab nrab thiab kev sib koom ua ke hydrogen chloride ntes cov peev txheej ntawm cov tshuaj lom neeg ua rau lawv cov thermal stability kev ua tau zoo los yog zoo dua rau qee lub tshuab organotin, thaum txo cov tshuaj lom thiab ib puag ncig. Hom kev sib xyaw no siv tag nrho cov txiaj ntsig ntawm cov khoom sib txawv ntawm cov tshuaj sib txawv, them nyiaj rau qhov tsis txaus ntawm ib qho khoom, thiab txhim kho kev ua tau zoo thiab siv tau.
Kev tsom xam thiab kev ua yam ntxwv ntawm cov khoom siv tshuaj lom neeg ua lub luag haujlwm tseem ceeb hauv kev txhim kho ntxiv thiab kev tswj kom zoo. Cov kev siv feem ntau suav nrog infrared spectroscopy (IR) txhawm rau txheeb xyuas cov pab pawg ua haujlwm, nuclear magnetic resonance (NMR) los daws cov qauv molecular, X-ray fluorescence (XRF) los txiav txim siab cov ntsiab lus hlau, thiab ntsuas ntsuas kub (TGA) los ntsuas thermal stability thiab decomposition tus cwj pwm. Cov kev txheeb xyuas no tsis tsuas yog txheeb xyuas qhov tseeb ntawm cov txheej txheem synthesis lossis kev sib xyaw ua ke tab sis kuj tseem muab cov hauv paus kev tshawb fawb rau kev tsim kho kom zoo thiab kev twv ua haujlwm.
Feem ntau, cov tshuaj muaj pes tsawg leeg ntawm PVC additives yog lub hauv paus rau lawv cov functionality. Ntau hom tshuaj muaj pes tsawg leeg txiav txim siab cov txheej txheem ntawm kev ua, cov yam ntxwv ntawm kev ua haujlwm, thiab kev siv ntau yam ntawm cov khoom ntxiv. Kev nkag siab zoo txog cov yam ntxwv thiab kev sib cuam tshuam cov cai ntawm ntau yam tshuaj lom neeg tuaj yeem muab kev txhawb nqa theoretical rau kev tsim qauv ntawm kev ua haujlwm zoo, ib puag ncig tus phooj ywg, thiab muaj kev nyab xeeb ntxiv, thiab txhawb kev txhim kho txuas ntxiv ntawm PVC cov ntaub ntawv hauv siab -kawg thiab kev siv tau zoo.