PVA molecular qauv
PVA, tshuaj hu ua polyvinyl cawv, muaj ntau pawg hydroxyl (-OH) ntawm nws cov saw molecular, uas ua rau nws "ua haujlwm tseem ceeb." Cov pab pawg hydroxyl no tuaj yeem tsim cov ntawv cog lus hydrogen, ua rau cov yeeb yaj kiab tawv tom qab ziab. Ib txhij, cov pab pawg hydroxyl yog hydrophilic heev, tso cai rau PVA yaj hauv dej ntawm qhov kub thiab txias -ib qho cuab yeej hu ua "qhuav zaj duab xis tsim thiab ntub dej so."
Kev ua yeeb yam
PVA feem ntau sib txawv los ntawm kev kho nws cov℃ntawm polymerization thiab℃ntawm alcoholysis kom tau raws li qhov yuav tsum tau ua nyob rau hauv ntau yam kev siv:
• Qib siab ntawm alcoholysis PVA (98%-99%): Txawm tias tsis muaj dej-soluble, nws nthuav tawm lub zog siab thiab cov khoom thaiv zoo, ua rau nws haum rau ntim cov yeeb yaj kiab, fibers, thiab lwm yam khoom.
• Tsawg℃ntawm alcoholysis PVA (87%-89%): Yooj yim soluble nyob rau hauv dej txias, nrog me ntsis qaug zog zaj duab xis- tsim cov khoom, nws yog haum rau siv raws li ib tug cab kuj nyob rau hauv cov tshuaj pleev ib ce thiab raws li ib tug dej-soluble nplaum nplaum.
Tsis tas li ntawd, PVA muaj qhov zoo xws li tsis yog - lom, biocompatible, thiab biodegradable, ua lub luag haujlwm tseem ceeb hauv kev kho mob thiab kev tiv thaiv ib puag ncig
Kev sib piv ntawm cov dej solubility thiab zaj duab xis lub zog ntawm PVA nrog ntau qib ntawm alcoholysis
Kev npaj
PVA monomers tsis ruaj khov thiab tsis tuaj yeem ncaj qha polymerized. Kev lag luam, txoj kev tsis ncaj ntawm "polyvinyl acetate (PVAc) polymerization → alcoholysis reaction → post-kev kho mob" feem ntau yog siv.
Daim ntawv thov
Kev siv cov khoom lag luam
Tshuaj pleev ib ce thiab tshuaj txhua hnub:
PVA hauv daim npog ntsej muag zoo nqus cov ntsiab lus thiab maj mam tso cov as-ham thaum sib cuag nrog daim tawv nqaij; PVA zaj duab xis- tsim cov tshuaj ntxiv rau cov tshuaj zawv plaub hau thiab cov tshuaj pleev ib ce ua cov yeeb yaj kiab tiv thaiv ntawm cov plaub hau, txhim kho smoothness; PVA los tiv thaiv- cov tshuaj tiv thaiv rov qab rau hauv cov ntxhua khaub ncaws ntxhua khaub ncaws tiv thaiv cov av los ntawm rov- ua raws li cov khaub ncaws.
Cov ntaub ntawv ntim khoom: Dej-soluble PVA ntim zaj duab xis yog dav siv rau me me -dose encapsulation ntawm cov tshuaj tua kab thiab tshuaj ntxuav tes, tshem tawm qhov xav tau ntawm kev ntim khoom thiab tiv thaiv kom tsis txhob muaj kab mob; PVA txheej hauv cov ntim khoom noj txhim kho cov khoom thaiv kev tiv thaiv thiab ua kom lub neej txee rau khoom noj.
thaj chaw kho mob
Pharmaceutical formulations:
Raws li cov khoom siv pabcuam rau cov tshuaj ntsiav, PVA tuaj yeem txhim kho qhov kev sib cais ntawm cov tshuaj ntsiav, kom ntseeg tau tias cov tshuaj raug tso tawm hauv lub cev; Nyob rau tib lub sijhawm, nws tuaj yeem siv los ua kom muaj kev txhawb nqa - tso cov neeg nqa tshuaj mus ntev - xa tshuaj.
Cov khoom siv kho mob: Dej- cov ntaub qhwv lub qhov txhab soluble tuaj yeem tiv thaiv qhov txhab, nqus cov exudate, tiv thaiv kev nplaum rau qhov txhab, thiab txo cov neeg mob kev txom nyem.
Cov teb tshiab
3D Printing: Tsawg-polymerization-degree PVA yog cov khoom siv zoo rau 3D luam ntawv, thiab nws tuaj yeem tshem tau yooj yim los ntawm kev ntxuav nrog dej tom qab luam ntawv.
Cov Khoom Siv Hluav Taws Xob: PVA- hloov kho electrolyte daim nyias nyias tuaj yeem txhim kho ion conduction efficiency ntawm cov roj teeb, muab kev txhawb nqa rau kev txhim kho cov khoom siv hluav taws xob hloov tau yooj yim
