Polyvinyl mowa PVA

Polyvinyl alcohol (PVA) ndi polima wopangidwa kuchokera ku vinyl acetate kudzera mu polymerization ndi hydrolysis wotsatira. Ndi polima yosungunuka m'madzi yokhala ndi ntchito zosiyanasiyana chifukwa cha mawonekedwe ake apadera. Tiyeni tiwone mbali zina zazikulu za mowa wa polyvinyl:

1. Kapangidwe ka Mankhwala: Mowa wa polyvinyl umadziwika ndi gawo lobwerezabwereza la vinyl mowa monomers. Magawo a mowa wa vinyl amalumikizidwa palimodzi ndi ma carbon-carbon single bond, kupanga mzere wozungulira wa polima. Komabe, mowa weniweni wa vinilu ndi wosakhazikika, kotero mowa wa polyvinyl umapangidwa ndi hydrolysis ya polyvinyl acetate, kumene magulu ena a acetate amasinthidwa ndi magulu a hydroxyl.

2. Katundu:

• Kusungunuka kwamadzi: Chimodzi mwazinthu zofunika kwambiri za PVA ndi kusungunuka kwake kwamadzi. Amasungunuka mosavuta m'madzi kuti apange njira zomveka bwino, zowoneka bwino, zomwe zimapangitsa kuti zikhale zoyenera kugwiritsa ntchito zosiyanasiyana zomwe zimafunikira madzi.
• Kutha Kupanga Mafilimu: PVA imatha kupanga makanema owoneka bwino, osinthika akatayidwa kuchokera kumadzi ake. Mafilimuwa ali ndi mphamvu zamakina abwino, zotchinga, komanso kumamatira kumagulu apansi, kuwapangitsa kukhala othandiza pakugwiritsa ntchito monga zokutira, zomatira, ndi zomangira.
• Biocompatibility: PVA nthawi zambiri imadziwika kuti ndi biocompatible komanso yopanda poizoni, ndikupangitsa kuti ikhale yoyenera kugwiritsidwa ntchito pazinthu zosiyanasiyana zachipatala ndi zamankhwala, monga njira zoperekera mankhwala, mavalidwe a bala, ndi ma scaffolds opangira minofu.
• Kukhazikika kwa Chemical: PVA imawonetsa kukhazikika kwamankhwala, kukana kuwonongeka ndi ma acid, maziko, ndi zosungunulira za organic pansi pamikhalidwe yabwinobwino. Komabe, imatha kukumana ndi hydrolysis pansi pa acidic kapena zamchere, zomwe zimabweretsa kuwonongeka kwa katundu.

3. Ntchito: Mowa wa polyvinyl uli ndi ntchito zosiyanasiyana m'mafakitale osiyanasiyana:

• Zomatira: Zomatira za PVA zimagwiritsidwa ntchito kwambiri popanga matabwa, kuyika mapepala pamapepala, ndi zinthu za ogula chifukwa chomatira bwino, kukana madzi, komanso kugwiritsa ntchito mosavuta.
• Zovala: Ulusi wa PVA amagwiritsidwa ntchito popanga nsalu kuti apatse mphamvu, kukana ma abrasion, komanso kukhazikika kwa nsalu.
• Kupaka: Makanema opangidwa ndi PVA amagwiritsidwa ntchito ngati zida zopangira chakudya, mankhwala, ndi zinthu zina chifukwa cha zotchinga zawo komanso kuwonongeka kwawo.
• Zopaka Papepala: Zopaka za PVA zimagwiritsidwa ntchito pamapepala ndi mapepala kuti zikhale zosalala, zosindikizidwa, komanso kukana chinyezi.
• Zomangamanga: Zopangira zopangidwa ndi PVA zimagwiritsidwa ntchito pomanga monga zosakaniza za simenti, zopangira pulasitala, ndi zosinthira matope kuti zithandizire kugwira ntchito, kumamatira, komanso kulimba.

4. Kuganizira Zachilengedwe: Ngakhale kuti mowa wa polyvinyl umatha kuwonongeka ndi zinthu zina, kugwiritsidwa ntchito kwake kofala ndi kutayidwa kungakhale ndi zotsatira za chilengedwe. Biodegradation ya PVA imachitika kudzera muzochita zazing'ono m'malo a aerobic, monga malo opangira manyowa kapena malo opangira madzi oyipa. Komabe, m'malo a anaerobic, monga zotayira pansi, PVA imatha kupitilira nthawi yayitali. Zoyeserera zopanga njira zina zowola kapena zongowonjezedwanso m'malo mwa PVA zachikhalidwe zikupitilira kuti muchepetse zovuta zachilengedwezi.

Mwachidule, mowa wa polyvinyl (PVA) ndi polima wosunthika womwe umagwiritsidwa ntchito mosiyanasiyana chifukwa cha kusungunuka kwake m'madzi, luso lopanga filimu, biocompatibility, komanso kukhazikika kwamankhwala. Amagwiritsidwa ntchito m'mafakitale monga zomatira, nsalu, kulongedza, zokutira mapepala, ndi zomangira. Ngakhale kuti PVA imapereka zabwino zambiri, kuganizira zachilengedwe ndi kuyesetsa kupanga njira zina zokhazikika ndizofunikira pakugwiritsa ntchito ndi chitukuko.