Polycarbonate (PC) ndi unyolo maselo munali carbonate gulu, malinga ndi dongosolo maselo ndi magulu osiyanasiyana ester, akhoza kugawidwa aliphatic, alicyclic, onunkhira, amene kwambiri zothandiza mtengo wa onunkhira gulu, ndi chofunika kwambiri bisphenol A mtundu polycarbonate, ambiri olemera pafupifupi maselo kulemera (Mw) mu 20-100,000.

Chithunzi PC structural formula

Polycarbonate ali ndi mphamvu zabwino, toughness, mandala, kutentha ndi kuzizira kukana, processing zosavuta, lawi retardant ndi ntchito zina mabuku, waukulu kumunsi ofunsira ndi zipangizo zamagetsi, pepala ndi magalimoto, mafakitale atatuwa nkhani pafupifupi 80% ya mowa polycarbonate, ena m'mafakitale makina CD-ROM, ma CD, ma CD, ma CD, ma CD, zida za ofesi, zipangizo za ofesi, zipangizo zachipatala, ndi zina zambiri zotetezera thanzi. ntchito zosiyanasiyana, kukhala imodzi mwa mapulasitiki asanu a uinjiniya omwe akukula mwachangu.

Mu 2020, padziko lonse PC kupanga mphamvu za matani 5.88 miliyoni, 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 kwa pafupifupi 1.38 miliyoni ku mayiko akunja, kufunikira kwa mayiko akunja 1.38 miliyoni. Kufuna kwakukulu kwa msika kwakopa mabizinesi ambiri kuti achulukitse kupanga, akuti pali ma projekiti ambiri a PC omwe akumangidwa ndikupangidwa ku China nthawi yomweyo, ndipo mphamvu zopanga zapakhomo zidzapitilira matani 3 miliyoni / chaka pazaka zitatu zikubwerazi, ndipo makampani a PC akuwonetsa chizolowezi chosamukira ku China.

Ndiye, ndi njira zotani zopangira PC? 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% yazinthu zamafakitale za polycarbonate zidapangidwa 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 bisphenol A yosungunuka ndi diphenyl carbonate (Diphenyl Carbonate, DPC), pa kutentha kwambiri, vacuum yayikulu, chothandizira kukhalapo kwa ester exchange, pre-condensation, condensation reaction.

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 mtundu womaliza 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 kuuma ndi kutsukidwa, ndipo khalidwe la mankhwala ndi labwino. Njirayi sigwiritsa ntchito phosgene, ndi yogwirizana ndi chilengedwe, ndipo ndi njira yobiriwira.

Ndi zofuna za dziko kwa mabizinesi a petrochemical 'zinyalala zitatu Ndi kuwonjezeka kwa zofunikira za dziko pa chitetezo ndi chitetezo cha chilengedwe cha mabizinesi a petrochemical ndi kuletsa kugwiritsa ntchito phosgene, ukadaulo wosapanga phosgene wosungunuka wa ester udzalowa m'malo mwa njira ya interfacial polycondensation m'tsogolomu monga chitsogozo cha chitukuko chaukadaulo cha PC padziko lonse lapansi.