Polycarbonate (PC) ndi unyolo wa molekyulu wokhala ndi gulu la carbonate, malinga ndi kapangidwe ka maselo ndi magulu osiyanasiyana a ester, amatha kugawidwa kukhala aliphatic, alicyclic, onunkhira, omwe mtengo wake wothandiza kwambiri wa gulu lonunkhira, komanso mtundu wofunikira kwambiri wa bisphenol A. polycarbonate, general heavy average molecular weight (Mw) mu 20-100,000.

Chithunzi PC structural formula

Polycarbonate imakhala ndi mphamvu zabwino, zolimba, zowonekera, kutentha ndi kuzizira, kukonza kosavuta, kutentha kwamoto ndi ntchito zina zonse, ntchito zazikulu zotsika pansi ndi zipangizo zamagetsi, mapepala ndi magalimoto, mafakitale atatuwa amawerengera pafupifupi 80% ya mowa wa polycarbonate, ena mu mbali zamakina zamakina, CD-ROM, zonyamula, zida zamaofesi, chithandizo chamankhwala ndi thanzi, filimu, zosangalatsa ndi zida zodzitetezera ndi magawo ena ambiri akwaniritsa. ntchito zosiyanasiyana, kukhala imodzi mwa mapulasitiki asanu a uinjiniya omwe akukula mwachangu.

Mu 2020, padziko lonse PC kupanga mphamvu pafupifupi 5.88 miliyoni matani, China PC kupanga mphamvu matani 1.94 miliyoni / chaka, kupanga pafupifupi 960,000 matani, pamene mowa zikuoneka wa polycarbonate ku China mu 2020 anafika matani 2.34 miliyoni, pali kusiyana. pafupifupi matani 1.38 miliyoni, ayenera kuitanitsa kuchokera kumayiko akunja. Kufuna kwakukulu kwa msika kwakopa ndalama zambiri kuti ziwonjezeke kupanga, akuti pali ma projekiti ambiri a PC omwe akumangidwa ndikuperekedwa ku China nthawi yomweyo, ndipo mphamvu zopanga zapakhomo zidzapitilira matani 3 miliyoni / chaka pazaka zitatu zikubwerazi, ndipo makampani a PC akuwonetsa njira yopititsira patsogolo ku China.

Ndiye, njira zopangira ma PC ndi ziti? Kodi mbiri yachitukuko cha PC kunyumba ndi kunja ndi chiyani? Kodi opanga ma PC akuluakulu ku China ndi ati? Kenaka, timapanga chisa pafupi.

Njira zitatu zazikulu zopangira ma PC

Njira ya interfacial polycondensation photogas, njira yachikhalidwe yosinthira ester yosungunula ndi njira yosinthira ma ester yopanda photogas ndi njira zitatu zazikulu zopangira makampani a PC.
Chithunzi Chithunzi
1. Interfacial polycondensation phosgene njira

Ndi mmene phosgene mu inert zosungunulira ndi amadzimadzi sodium hydroxide njira bisphenol A kupanga ang'onoang'ono molekyulu kulemera polycarbonate, ndiyeno condensed kukhala mkulu molecular polycarbonate. Panthawi ina, pafupifupi 90% ya mafakitale a polycarbonate adapangidwa ndi njira iyi.

Ubwino wa interfacial polycondensation phosgene njira PC ndi mkulu wachibale kulemera maselo, amene angafikire 1.5 ~ 2 * 105, ndi mankhwala koyera, katundu kuwala, bwino hydrolysis kukana, ndi processing zosavuta. Choyipa chake ndi chakuti njira yopangira ma polymerization imafuna kugwiritsa ntchito phosgene yapoizoni komanso zosungunulira zapoizoni komanso zosakhazikika monga methylene chloride, zomwe zimayambitsa kuipitsidwa kwakukulu kwa chilengedwe.

Njira yosinthira ester, yomwe imadziwikanso kuti ontogenic polymerization, idapangidwa koyamba ndi Bayer, pogwiritsa ntchito chitsulo chosungunuka cha bisphenol A ndi diphenyl carbonate (Diphenyl Carbonate, DPC), pakutentha kwambiri, vacuum yayikulu, chothandizira kukhalapo kwa ester exchange, pre-condensation, condensation. anachita.

Malinga ndi zida zomwe zimagwiritsidwa ntchito munjira ya DPC, zitha kugawidwa m'njira zachikhalidwe zosungunula ester (yomwe imadziwikanso kuti indirect photogas njira) ndi njira yosinthira ma ester osakhala photogas.

2. Traditional yosungunuka ester kuwombola njira

Imagawidwa m'masitepe awiri: (1) phosgene + phenol → DPC; (2) DPC + BPA → PC, yomwe ndi njira yosalunjika ya phosgene.

Njirayi ndi yaifupi, yopanda zosungunulira, ndipo mtengo wake ndi wotsika pang'ono kuposa njira ya interfacial condensation phosgene, koma kupanga kwa DPC kumagwiritsabe ntchito phosgene, ndipo mankhwala a DPC amakhala ndi magulu a chloroformate, omwe angakhudze chomaliza. Ubwino wa PC, womwe umalepheretsa kukwezedwa kwa njirayi.

3. Non-phosgene molt ester kusintha njira

Njirayi imagawidwa m'magulu awiri: (1) DMC + phenol → DPC; (2) DPC + BPA → PC, yomwe imagwiritsa ntchito dimethyl carbonate DMC ngati zopangira ndi phenol kupanga DPC.

The by-product phenol yomwe imapezeka kuchokera ku ester exchange and condensation ikhoza kubwezeretsedwanso ku kaphatikizidwe ka ndondomeko ya DPC, potero kuzindikira kugwiritsiranso ntchito zinthu ndi chuma chabwino; chifukwa cha chiyero chapamwamba cha zipangizo, mankhwalawo safunikiranso kuumitsa ndi kutsukidwa, ndipo khalidwe la mankhwala ndi labwino. Njirayi sigwiritsa ntchito phosgene, ndi yogwirizana ndi chilengedwe, ndipo ndi njira yobiriwira.

Ndi zofunikira za dziko la mabizinesi a petrochemical 'zinyalala zitatu Ndi kuwonjezeka kwa zofunikira za dziko pa chitetezo ndi chitetezo cha chilengedwe cha mabizinesi a petrochemical komanso kuletsa kugwiritsa ntchito phosgene, ukadaulo wosapanga phosgene molt ester exchange isintha pang'onopang'ono njira ya interfacial polycondensation mu tsogolo monga chitsogozo cha chitukuko chaukadaulo wopanga ma PC padziko lapansi.