Polyvinyl cawv PVA

Polyvinyl cawv (PVA) yog ib qho hluavtaws polymer muab los ntawm vinyl acetate los ntawm polymerization thiab tom qab hydrolysis. Nws yog cov dej-soluble polymer nrog ntau yam kev siv vim nws cov khoom tshwj xeeb. Cia peb tshawb txog qee qhov tseem ceeb ntawm polyvinyl cawv:

1. Chemical Structure: Polyvinyl cawv yog tus cwj pwm los ntawm kev rov ua dua tshiab ntawm vinyl cawv monomers. Cov vinyl cawv chav nyob yog txuas ua ke los ntawm cov pa roj carbon-carbon ib daim ntawv cog lus, tsim ib txoj hlua polymer. Txawm li cas los xij, vinyl cawv ntshiab tsis ruaj khov, yog li polyvinyl cawv feem ntau yog tsim los ntawm hydrolysis ntawm polyvinyl acetate, qhov twg qee pawg acetate hloov nrog hydroxyl pawg.

2. Khoom:

• Dej Solubility: Ib qho tseem ceeb tshaj plaws ntawm PVA yog nws cov dej solubility siab. Nws yooj yim yaj hauv dej los tsim cov kev daws teeb meem ntshiab, ua kom haum rau ntau yam kev siv uas yuav tsum muaj cov qauv dej.
• Film-Forming Muaj peev xwm: PVA tuaj yeem tsim cov duab pob tshab, hloov tau yooj yim thaum nrum los ntawm nws cov kua dej. Cov yeeb yaj kiab no muaj lub zog zoo txhua yam, cov khoom thaiv kev tiv thaiv, thiab adhesion rau cov substrates, ua rau lawv muaj txiaj ntsig zoo hauv kev siv xws li coatings, adhesives, thiab ntim khoom.
• Biocompatibility: PVA feem ntau suav hais tias yog biocompatible thiab tsis muaj tshuaj lom, ua rau nws haum rau siv ntau yam kev kho mob thiab tshuaj siv, xws li kev xa tshuaj, kev hnav khaub ncaws, thiab cov ntaub so ntswg engineering scaffolds.
• Chemical Stability: PVA pom zoo tshuaj stability, tiv thaiv degradation los ntawm acids, bases, thiab organic solvents nyob rau hauv ib txwm tej yam kev mob. Txawm li cas los xij, nws tuaj yeem raug hydrolysis nyob rau hauv acidic lossis alkaline tej yam kev mob, ua rau poob ntawm cov khoom.

3. Daim Ntawv Thov: Polyvinyl cawv muaj ntau yam kev siv thoob plaws ntau yam kev lag luam:

• Adhesives: PVA-raws li adhesives yog dav siv nyob rau hauv woodworking, paperboard ntim, thiab cov neeg siv khoom vim lawv zoo heev adhesion, dej tsis kam, thiab yooj yim ntawm kev siv.
• Textiles: PVA fibers yog siv nyob rau hauv daim ntawv thov textile los muab lub zog, abrasion tsis kam, thiab seem stability rau fabrics.
• Ntim: PVA-raws li cov yeeb yaj kiab yog siv los ua cov khoom ntim khoom noj, tshuaj, thiab lwm yam khoom vim lawv cov khoom thaiv thiab biodegradability.
• Daim Ntawv Txheej: PVA-raws li txheej yog siv rau daim ntawv thiab cov ntaub ntawv los txhim kho qhov smoothness, printability, thiab ya raws.
• Kev tsim kho: PVA-raws li formulations yog siv rau hauv cov khoom siv xws li cement admixtures, plaster additives, thiab mortar modifiers los txhim kho kev ua hauj lwm, adhesion, thiab durability.

4. Kev txiav txim siab ib puag ncig: Txawm hais tias polyvinyl cawv yog biodegradable nyob rau hauv tej yam kev mob, nws dav siv thiab pov tseg tseem tuaj yeem cuam tshuam ib puag ncig. Biodegradation ntawm PVA feem ntau tshwm sim los ntawm kev ua microbial nyob rau hauv ib puag ncig aerobic, xws li composting chaw lossis cov chaw kho dej khib nyiab. Txawm li cas los xij, nyob rau hauv ib puag ncig anaerobic, xws li cov chaw pov tseg, PVA tuaj yeem nyob mus ntev. Kev siv zog los txhim kho biodegradable lossis rov ua dua tshiab rau cov qauv PVA ib txwm muaj txuas ntxiv los txo cov kev txhawj xeeb ntawm ib puag ncig.

Hauv cov ntsiab lus, polyvinyl cawv (PVA) yog ntau yam polymer nrog ntau yam kev siv vim nws cov dej solubility, muaj peev xwm tsim zaj duab xis, biocompatibility, thiab tshuaj stability. Nws siv dav hauv kev lag luam xws li adhesives, textiles, ntim, ntawv txheej, thiab cov ntaub ntawv tsim kho. Thaum PVA muaj ntau qhov zoo, kev txiav txim siab ib puag ncig thiab kev siv zog los tsim cov kev hloov pauv tau zoo yog qhov tseem ceeb hauv nws txoj kev siv txuas ntxiv thiab txhim kho.