Vim li cas cov kua silicone tuaj yeem siv dav hauv ntau qhov chaw?

1.Introduction ntawm cov kua silicone roj hmab nrog ntxiv molding

kua silicone roj hmab nrog ntxiv molding yog tsim los ntawm vinyl polysiloxane raws li lub hauv paus polymer, polysiloxane nrog Si-H daim ntawv cog lus raws li tus ntoo khaub lig linking tus neeg sawv cev, nyob rau hauv lub xub ntiag ntawm platinum catalyst, nyob rau hauv chav tsev kub los yog cua sov nyob rau hauv tus ntoo khaub lig linking vulcanization ntawm ib chav kawm ntawm silicone. cov ntaub ntawv. Sib txawv ntawm condensed kua silicone roj hmab, molding kua silicone vulcanization txheej txheem tsis tsim los ntawm cov khoom, me me shrinkage, sib sib zog nqus vulcanization thiab tsis muaj corrosion ntawm cov khoom siv. Nws muaj qhov zoo ntawm qhov kub thiab txias ntau yam, tshuaj lom neeg ua haujlwm zoo thiab huab cua tsis kam, thiab tuaj yeem ua tau yooj yim rau ntau qhov chaw. Yog li ntawd, piv nrog cov condensed kua silicone, txoj kev loj hlob ntawm cov kua silicone molding yog sai dua. Tam sim no, nws tau siv ntau dua thiab dav siv hauv cov khoom siv hluav taws xob, tshuab, kev tsim kho, kev kho mob, tsheb thiab lwm yam.

2.Main Components

Base Polymer

Cov nram qab no ob kab polysiloxane uas muaj vinyl yog siv los ua lub hauv paus polymers rau ntxiv cov kua silicone. Lawv qhov hnyav molecular faib yog dav, feem ntau ntawm ntau txhiab mus rau 100,000-200,000. Qhov feem ntau siv puag polymer rau additive kua silicone yog α,ω -divinylpolydimethylsiloxane. Nws tau pom tias qhov hnyav molecular thiab vinyl cov ntsiab lus ntawm cov polymers yooj yim tuaj yeem hloov cov khoom ntawm cov kua silicone.

cross-linking agent

Tus neeg sawv cev crosslinking siv rau kev ntxiv molding kua silicone yog cov organic polysiloxane uas muaj ntau tshaj 3 Si-H bonds nyob rau hauv lub molecule, xws li linear methyl-hydropolysiloxane uas muaj Si-H pawg, nplhaib methyl-hydropolysiloxane thiab MQ resin muaj Si-H pawg. Feem ntau siv yog linear methylhydropolysiloxane ntawm cov qauv hauv qab no. Nws tau pom tias cov khoom siv kho tshuab ntawm silica gel tuaj yeem hloov pauv los ntawm kev hloov cov ntsiab lus hydrogen lossis cov qauv ntawm tus neeg sawv cev sib txuas. Nws pom tias cov ntsiab lus hydrogen ntawm tus neeg sawv cev crosslinking yog proportional rau lub zog tensile thiab hardness ntawm silica gel. Gu Zhujiang et al. tau txais hydrogen-muaj silicone roj nrog cov qauv sib txawv, sib txawv molecular hnyav thiab cov ntsiab lus hydrogen sib txawv los ntawm kev hloov cov txheej txheem synthesis thiab mis, thiab siv nws ua tus neeg sawv cev crosslinking los ua ke thiab ntxiv cov kua silicone.

catalyzer

Txhawm rau txhim kho cov txiaj ntsig catalytic ntawm catalysts, platinum-vinyl siloxane complexes, platinum-alkyne complexes thiab nitrogen-hloov platinum complexes tau npaj. Ntxiv nrog rau hom catalyst, tus nqi ntawm cov khoom ua kua silicone kuj tseem cuam tshuam rau kev ua haujlwm. Nws pom tias nce qhov concentration ntawm platinum catalyst tuaj yeem txhawb kev sib txuas cov tshuaj tiv thaiv ntawm methyl pawg thiab inhibit qhov decomposition ntawm cov saw tseem ceeb.

Raws li tau hais los saum no, vulcanization mechanism ntawm cov tshuaj additive silicone yog cov tshuaj tiv thaiv hydrosilylation ntawm lub hauv paus polymer uas muaj vinyl thiab cov polymer uas muaj hydrosilylation daim ntawv cog lus. Cov tshuaj ua kua silicone additive molding feem ntau xav tau pwm nruj los tsim cov khoom kawg, tab sis cov khoom siv niaj hnub no muaj qhov tsis zoo ntawm tus nqi siab, lub sijhawm ntev, thiab lwm yam. Cov khoom siv feem ntau tsis siv rau cov khoom siv hluav taws xob. Cov kws tshawb nrhiav pom tias cov khoom siv silica uas muaj cov khoom zoo tshaj tuaj yeem npaj tau los ntawm cov txheej txheem kho tshiab siv mercaptan - ob daim ntawv cog lus ntxiv kua silica. Nws cov khoom siv zoo heev, thermal stability thiab lub teeb xa hluav taws xob tuaj yeem ua rau nws siv rau hauv ntau qhov chaw tshiab. Raws li mercapto-ene daim ntawv cog lus cov tshuaj tiv thaiv ntawm branched mercaptan functionalized polysiloxane thiab vinyl terminated polysiloxane nrog txawv molecular hnyav, silicone elastomers nrog adjustable hardness thiab mechanical zog tau npaj. Cov ntawv luam tawm elastomers qhia cov kev daws teeb meem siab thiab cov khoom siv tshuab zoo heev. Lub elongation ntawm kev tawg ntawm silicone elastomers tuaj yeem ncav cuag 1400%, uas yog siab dua li tshaj tawm UV kho elastomers thiab txawm siab tshaj qhov stretchable thermal curing silicone elastomers. Tom qab ntawd ultra-stretchable silicone elastomers tau siv rau hydrogels doped nrog carbon nanotubes los npaj cov khoom siv hluav taws xob stretchable. Printable thiab processable silicone muaj dav daim ntawv thov kev cia siab nyob rau hauv mos robots, saj zawg zog actuators, kho mob cog thiab lwm yam teb.