Abstract
Thermal stabilizers tiv thaiv polymers los ntawm cov tshuaj degradation los ntawm tshav kub los yog UV hluav taws xob. Cov additives no suav nrog ntau yam tshuaj, los ntawm cov tshuaj organic ntshiab mus rau cov xab npum hlau mus rau cov organometallic complex. Txog tam sim no, feem ntau cov polymer xav tau kev siv cov khoom siv hluav taws xob kub yog polyvinyl chloride (PVC). Txawm li cas los xij, copolymers ntawm PVC, chlorinated polyvinyl chloride (CPVC), polyvinylidene chloride (PVDC) thiab chlorinated polyethylene (CPE) kuj tau txais txiaj ntsig los ntawm cov thev naus laus zis no. PVC yog cov chav kawm tseem ceeb tshaj plaws ntawm halogenated polymers xav tau cov tshuaj ntxiv no.
Hauv kev ua haujlwm ib txwm muaj, PVC resin yog sib xyaw nrog cov khoom xyaw uas xav tau nyob rau hauv siab shear sib xyaw ua ke los tsim ib homogeneous qhuav hmoov compound. Thaum tshav kub kub stabilizers tuaj yeem ua kua lossis hmoov thiab ntxiv rau thaum ntxov ntawm lub voj voog sib xyaw kom muaj kev ruaj khov thaum lub sijhawm ua haujlwm no. Preheating cov resin mus rau kwv yees li lub iav hloov pauv kub ua kom lub adsorption ntawm cov kua additives, uas ua rau cov hmoov ntws zoo dua thiab qis dua qhov ntom ntom hauv qhov kawg. Kev ua haujlwm tom qab sib xyaw ua ke, xws li extrusion pelletization, nce tag nrho cov keeb kwm thermal ntawm cov polymer, yog li me ntsis siab dua cov thermal stabilizers yuav tsum tau them rau qhov no.
Organotin raws li kub stabilizers yog qhov zoo tshaj plaws thiab feem ntau siv PVC stabilizers. Cov no yog cov derivatives ntawm tetravalent tin. Qhov thib ob feem ntau siv stabilizer yog cov hlau sib xyaw ua ke. Cov khoom lag luam no tswj hwm cov ntawv siv PVC yooj yim hauv Tebchaws Meskas. Lub lag luam tseem ceeb alkali thiab alkaline ntiaj teb hlau raws li ntsev thiab xab npum ntawm calcium, zinc, magnesium, barium thiab cadmium siv nyob rau hauv cov stabilizer systems. Lwm cov organic tebchaw xws li phosphites, epoxides, polyols thiab beta-diketones kuj tuaj yeem muab ntxiv los txhim kho kev ua haujlwm ntxiv. Antimony mercaptan stabilizers kuj tseem siv.
