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Tanthauzo la pulasitiki mu chemistry (II)

M'nkhaniyi, tikupitiriza kumvetsetsa kwathu kwa mapulasitiki kuchokera kumaganizo a mankhwala.
Katundu wa pulasitiki: Kapangidwe ka pulasitiki kumadalira pa kapangidwe kake ka magawo ang'onoang'ono, momwe zigawozo zimasanjidwira, ndi momwe zimapangidwira.Mapulasitiki onse ndi ma polima, koma si ma polima onse ndi mapulasitiki.Ma polima apulasitiki amapangidwa ndi maunyolo amagulu olumikizana omwe amatchedwa ma monomers.Ngati ma monomers omwewo alumikizidwa, homopolymer imapangidwa.Ma monomers osiyanasiyana amalumikizidwa kuti apange ma copolymers.Ma homopolymers ndi copolymers amatha kukhala amtundu kapena nthambi.Zina za pulasitiki ndi izi: Pulasitiki nthawi zambiri imakhala yolimba.Zitha kukhala zolimba za amorphous, zolimba za crystalline kapena zolimba za semi-crystalline (microcrystals).Mapulastiki nthawi zambiri amakhala okonda kutentha ndi magetsi.Ambiri ndi ma insulators okhala ndi mphamvu yayikulu ya dielectric.Ma polima agalasi amakhala olimba (mwachitsanzo, polystyrene).Komabe, flakes wa ma polima angagwiritsidwe ntchito ngati mafilimu (mwachitsanzo polyethylene).Pafupifupi mapulasitiki onse amawonetsa kutalika akapanikizika ndipo samachira pamene kupsinjika kumachepetsedwa.Izi zimatchedwa "kukwawa".Mapulasitiki amakhala olimba komanso amawonongeka pang'onopang'ono.

Mfundo zina zokhudza mapulasitiki: Pulasitiki yoyamba yopangidwa mokwanira inali BAKELITE, yopangidwa ndi LEO BAEKELAND mu 1907. Anapanganso mawu oti "pulasitiki".Mawu oti “pulasitiki” amachokera ku liwu lachi Greek lakuti PLASTIKOS, kutanthauza kuti akhoza kupangidwa kapena kuumbidwa.Pafupifupi gawo limodzi mwa magawo atatu a pulasitiki opangidwa amagwiritsidwa ntchito kupanga zolembera.Chachitatu chinacho chimagwiritsidwa ntchito pomanga mapaipi ndi mapaipi.Pulasitiki yoyera nthawi zambiri imakhala yosasungunuka m'madzi komanso yopanda poizoni.Komabe, zowonjezera zambiri mu mapulasitiki ndi poizoni ndipo zimatha kulowa m'chilengedwe.Zitsanzo za zowonjezera poizoni ndi phthalates.Ma polima opanda poizoni amathanso kutsika kukhala mankhwala akatenthedwa.
Pambuyo powerenga izi, mwakulitsa kumvetsetsa kwanu kwa mapulasitiki?


Nthawi yotumiza: Sep-17-2022