Vulcanization Txoj Cai ntawm Liquid Silicone Rubber
Lub hauv paus ntsiab lus ntawm vulcanization ntawm cov kua silicone roj hmab feem ntau cuam tshuam nrog cov txheej txheem ntawm kev hloov ntawm cov kua mus rau hauv lub xeev cov khoom, thaum lub sij hawm cov tshuaj tiv thaiv ua rau tsim ntawm cross-linked lug ntawm silicone roj hmab molecular chains, yog li imparting tshwj xeeb lub cev thiab tshuaj. Lub hauv paus ntsiab lus ntawm vulcanization ntawm kua silicone roj hmab tuaj yeem piav qhia raws li hauv qab no:
1. Basic Vulcanization txheej txheem
Vulcanization yog cov kauj ruam tseem ceeb hauv kev hloov cov kua roj hmab silicone los ntawm cov khoom ua kua rau hauv cov khoom siv. Vulcanization tsis tsuas yog hardens cov kua silicone roj hmab tab sis kuj tseem txhim khu nws lub zog tensile, tshav kub tsis kam, thiab lwm yam khoom siv kho tshuab.
2. Hom Vulcanization Reactions
Cov tshuaj tiv thaiv vulcanization ntawm cov kua silicone roj hmab tuaj yeem muab faib ua ob hom tseem ceeb: cov tshuaj tiv thaiv ib leeg vulcanization thiab dual-tiv thaiv vulcanization.
Ib leeg-Component Vulcanization Reaction:Hauv cov tshuaj tiv thaiv no, tus neeg sawv cev vulcanizing (xws li peroxides lossis imines) reacts nrog silicon-hydrogen bonds (Si-H bonds) muaj nyob rau hauv cov kua silicone roj hmab. Daim ntawv cog lus silicon-hydrogen yog qhov tseem ceeb heev rau cov kua roj hmab silicone muaj peev xwm sib txuas nrog lwm cov organic tebchaw lossis hlau. Tus neeg sawv cev vulcanizing ua tus catalyst, txhawb kev sib txuas cov tshuaj tiv thaiv ntawm silicon-hydrogen bonds los tsim cov qauv khoom.
Dual-Component Vulcanization Reaction:Cov tshuaj tiv thaiv no suav nrog kev siv ob yam sib txawv vulcanizing agents lossis cross-linking agents. Ib qho kev sib xyaw ua ke yog siv cov roj silicone uas muaj hydrogen los ua tus neeg sawv cev sib txuas, uas cuam tshuam nrog lub hauv paus polymer (xws li roj hmab silicone) los ntawm hydrosilylation nyob rau hauv lub xub ntiag ntawm catalyst. Lwm qhov xwm txheej cuam tshuam nrog kev siv ob lub kua roj hmab silicone roj hmab uas vulcanize los ntawm cov tshuaj tiv thaiv tshwj xeeb (xws li cov tshuaj tiv thaiv condensation) tom qab sib tov.
3. Tshwj xeeb Vulcanization Mechanisms
Ntxiv-kho Vulcanization:Rau ntxiv-kho kua silicone roj hmab, cov txheej txheem vulcanization feem ntau yog nyob ntawm hydrosilylation cov tshuaj tiv thaiv ntawm cov roj hmab silicone thiab cov roj silicone uas muaj hydrogen, catalyzed los ntawm kev hloov hlau complexes xws li platinum, rhodium, los yog palladium. Cov tshuaj tiv thaiv no tshwm sim los ntawm kev sib koom ua ke ntxiv cov txheej txheem, muab cov kev ua haujlwm siab, cov tshuaj tiv thaiv me me, thiab tswj tau yooj yim cov tshuaj tiv thaiv.
Condensation-Cure Vulcanization:Rau condensation-kho dual-component RTV (Room Temperature Vulcanizing) kua silicone roj hmab, cov txheej txheem vulcanization yog raws li cov condensation cross-linking cov tshuaj tiv thaiv ntawm cov hydroxyl pawg ntawm qhov kawg ntawm lub hauv paus polymer chains thiab hydrolyzable pawg nyob rau hauv cross-linking. tus neeg sawv cev, catalyzed los ntawm ib tug catalyst. Cov tshuaj tiv thaiv no tso tawm me me molecules (xws li dej los yog cawv) thiab tsim kom muaj kev sib txuas ruaj khov.
4. Lub luag haujlwm ntawm Vulcanizing Agents
Cov neeg ua haujlwm vulcanizing ua lub luag haujlwm tseem ceeb hauv cov txheej txheem vulcanization ntawm cov kua silicone roj hmab. Lawv tsis tsuas yog catalyze tus cross-linking tshua ntawm silicon-hydrogen bonds los yog lwm pab pawg neeg ua hauj lwm tab sis kuj cuam tshuam tus nqi ntawm vulcanization cov tshuaj tiv thaiv thiab cov khoom ntawm cov khoom kawg. Cov neeg ua haujlwm vulcanizing feem ntau suav nrog peroxides, imines, thiab cov hlau hloov pauv.
Hauv cov ntsiab lus, lub hauv paus ntsiab lus ntawm vulcanization ntawm cov kua silicone roj hmab yog cov txheej txheem tshuaj lom neeg cov tshuaj tiv thaiv uas muaj cov tshuaj tiv thaiv ib leeg lossis dual-tiv thaiv vulcanization, ntxiv lossis condensation cov tshuaj tiv thaiv, thiab cov tshuaj tiv thaiv catalytic ntawm cov tshuaj vulcanizing. Cov txheej txheem no yog qhov tseem ceeb rau kev molding, kev ua tau zoo, thiab kev nthuav dav ntawm cov kua silicone roj hmab.