Polyvinyl chloride (PVC), uas yog ib qho ntawm lub ntiaj teb loj tshaj plaws - tsim dav dav - plastics lub hom phiaj, yog siv dav hauv kev tsim kho, ntim khoom, xaim thiab cable, khoom siv kho mob, thiab cov khoom siv niaj hnub vim nws cov khoom siv raw khoom ntau, tus nqi qis, thiab kev ua haujlwm yooj yim. Txawm li cas los xij, ntshiab PVC resin raug kev txom nyem los ntawm kev tsis zoo thermal stability, tsis muaj kev cuam tshuam lub zog, kev ua haujlwm tsis zoo, thiab tsis muaj huab cua tsis kam thaum ua thiab siv, yuav tsum tau ntxiv ntau yam khoom siv ntxiv. Yog li ntawd, PVC additives tau dhau los ua qhov tseem ceeb txhawb kev txiav txim siab qhov zoo thiab siv tau ntawm nws cov khoom.
Ntawm ntau cov additives, cov cua sov stabilizers yog qhov tseem ceeb. PVC yog nquag dehydrochlorination thaum lub sij hawm ua cua sov, ua rau molecular saw cross-txuas los yog breakage, ua rau discoloration, embrittlement, thiab txawm poob ntawm usability. Hlau soaps, organotin tebchaw, thiab calcium-zinc composite stabilizers zoo txuas ntxiv cov resin lub thermal stability lub sij hawm los ntawm absorbing los yog neutralizing cov generated hydrogen chloride, hloov unstable chlorine atoms, los yog thaiv cov chain reactions, kom muaj kev ruaj ntseg ntawm cov txheej txheem xws li extrusion, calender molding.
Plasticizers yog cov khoom tseem ceeb rau kev txhim kho qhov yooj yim thiab kev ua haujlwm ntws ntawm PVC. Phthalate esters tau siv ib zaug, tab sis nrog kev xav tau ntawm ib puag ncig thiab kev noj qab haus huv, citrate esters, epoxidized soybean oil, thiab polyester plasticizers tau pom lawv daim ntawv thov nthuav dav vim lawv tsis muaj tshuaj lom thiab tsiv teb tsaws, tshwj xeeb tshaj yog hauv cov ntim khoom noj, cov khoom me me, thiab cov khoom siv kho mob. Hom thiab tus nqi ntawm plasticizer ncaj qha cuam tshuam rau hardness, elasticity, thiab qis - qhov kub thiab txias ntawm cov khoom tiav.
Impact modifiers yog siv los kov yeej lub brittleness ntawm PVC tawv. Acrylic copolymer, chlorinated polyethylene (CPE), thiab methyl methacrylate-butadiene-styrene copolymer (MBS) tuaj yeem tsim micro- cov cheeb tsam tawv hauv cov matrix, absorbing cuam tshuam lub zog thiab inhibiting tawg propagation, yog li txhim kho qhov cuam tshuam lub qhov rooj ntawm cov khoom siv, cov khoom siv thiab cov yeeb nkab. thiab ntawv.
Kev pab cuam feem ntau txhim kho cov dej ntws thiab plasticizing tus cwj pwm ntawm PVC yaj. Acrylic polymers tuaj yeem txhawb cov particle melting, txo cov viscosity yaj, thiab tshem tawm qhov tsis xws luag xws li sharkskin, txhim kho kev tsim khoom thiab cov khoom tiav, thiab tshwj xeeb tshaj yog tsim rau profile extrusion thiab zaj duab xis tshuab molding.
Lubricants tau muab faib ua ob pawg: cov lubricants sab hauv thiab cov lubricants sab nraud. Internal lubricants txo kev sib txhuam ntawm cov resin molecules, txhawb cov yas zoo tib yam; sab nraud lubricants txo adhesion ntawm cov ntaub ntawv thiab cov khoom siv nto, ua kom du ua thiab tiv thaiv overheating thiab decomposition. Kev tsim kom zoo tuaj yeem zam qhov kev hloov pauv zoo los ntawm cov yas tsis zoo lossis cov yaj ntau dhau.
Tsis tas li ntawd, antioxidants, lub teeb stabilizers, nplaim taws retardants, fillers, thiab colorants raug xaiv raws li lub hom phiaj ntawm kev siv cov khoom. Antioxidants thiab lub teeb stabilizers tuaj yeem ncua kev laus thiab txuas ntxiv lub neej ntawm cov khoom sab nraum zoov; nplaim retardants txhim kho kev nyab xeeb ntawm hluav taws xob thiab khoom siv hauv tsev; fillers tuaj yeem txhim kho qhov ruaj khov thiab rigidity thaum txo cov nqi; thiab colorants muab cov khoom nrog nplua nuj xim qhia.
Zuag qhia tag nrho, PVC additive system yog tus cwj pwm los ntawm nws cov haujlwm sib txawv thiab muaj zog sib koom ua ke. Kev sib xyaw ua ke ntawm cov khoom sib txawv tuaj yeem tsis tsuas yog them nyiaj rau qhov tsis xws luag ntawm PVC tab sis kuj ua tiav kev txhim kho kev ua haujlwm, txhua yam muaj zog, kav ntev, thiab kev nyab xeeb thiab kev ua haujlwm ib puag ncig. Nrog rau kev nce qib ntawm kev tsim ntsuab thiab kev thov rau kev ua haujlwm siab, cov khoom siv ntxiv tau tsim los ntawm cov tshuaj lom neeg tsawg, kev ua haujlwm siab, thiab kev sib koom ua ke ntau, muab kev txhawb zog rau kev nthuav dav ntawm PVC hauv siab - kawg thiab cov chaw tawm tshiab.