Polycarbonate (PC) yog cov saw hlau molecular uas muaj carbonate pawg, raws li cov qauv molecular nrog ntau pawg ester, tuaj yeem muab faib ua aliphatic, alicyclic, aromatic, uas yog cov txiaj ntsig zoo tshaj plaws ntawm pawg aromatic, thiab tseem ceeb tshaj plaws bisphenol A hom. polycarbonate, qhov hnyav nruab nrab molecular hnyav (Mw) hauv 20-100,000.

Daim duab PC structural formula

Polycarbonate muaj lub zog zoo, toughness, pob tshab, kub thiab txias tsis kam, ua haujlwm yooj yim, nplaim taws thiab lwm yam kev ua tau zoo, cov khoom siv qis qis yog cov khoom siv hluav taws xob, daim ntawv thiab tsheb, peb qhov kev lag luam no suav txog li 80% ntawm polycarbonate noj, lwm yam hauv industrial machinery qhov chaw, CD-ROM, ntim, khoom siv hauv chaw ua haujlwm, kev kho mob thiab kev noj qab haus huv, zaj duab xis, kev lom zem thiab cov khoom siv tiv thaiv thiab ntau lwm yam haujlwm kuj tau ua tiav. ntau yam kev siv, dhau los ua ib qho ntawm tsib engineering plastics hauv kev loj hlob sai tshaj plaws.

Nyob rau hauv 2020, lub ntiaj teb no PC ntau lawm muaj peev xwm ntawm txog 5.88 lab tons, Tuam Tshoj lub PC ntau lawm muaj peev xwm ntawm 1.94 lab tons / xyoo, ntau lawm ntawm 960,000 tons, thaum lub pom meej noj ntawm polycarbonate nyob rau hauv Tuam Tshoj nyob rau hauv 2020 mus txog 2.34 lab tons, muaj qhov sib txawv. ntawm ze li ntawm 1.38 lab tons, yuav tsum tau import los ntawm txawv teb chaws. Cov kev lag luam loj loj tau nyiam ntau qhov kev nqis peev los nce kev tsim khoom, nws kwv yees tias muaj ntau lub PC ua haujlwm hauv kev tsim kho thiab npaj rau hauv Suav teb tib lub sijhawm, thiab cov peev txheej tsim khoom hauv tsev yuav ntau dua 3 lab tons / xyoo hauv peb xyoos tom ntej, thiab PC kev lag luam qhia tau hais tias muaj kev sib hloov ceev ntawm kev hloov mus rau Tuam Tshoj.

Yog li, dab tsi yog cov txheej txheem tsim khoom ntawm PC? Dab tsi yog qhov kev txhim kho keeb kwm ntawm PC hauv tsev thiab txawv teb chaws? Dab tsi yog cov tuam txhab PC tseem ceeb hauv Suav teb? Tom ntej no, peb luv luv ua ib tug zuag.

PC peb txoj kev tsim cov txheej txheem tseem ceeb

Interfacial polycondensation photogas txoj kev, tsoos molten ester pauv txoj kev thiab tsis-photogas molten ester pauv txoj kev yog peb lub ntsiab ntau lawm txheej txheem nyob rau hauv lub PC kev lag luam.
Duab Duab
1. Interfacial polycondensation phosgene txoj kev

Nws yog cov tshuaj tiv thaiv ntawm phosgene rau hauv inert hnyav thiab aqueous sodium hydroxide tov ntawm bisphenol A los tsim me me molecular hnyav polycarbonate, thiab ces condensed rau hauv siab molecular polycarbonate. Nyob rau tib lub sijhawm, kwv yees li 90% ntawm cov khoom lag luam polycarbonate tau tsim los ntawm txoj kev no.

Qhov zoo ntawm interfacial polycondensation phosgene txoj kev PC yog siab txheeb ze molecular hnyav, uas muaj peev xwm ncav cuag 1.5 ~ 2 * 105, thiab cov khoom ntshiab, zoo optical zog, zoo hydrolysis kuj, thiab yooj yim ua. Qhov tsis zoo yog tias cov txheej txheem polymerization yuav tsum tau siv cov phosgene lom heev thiab cov kuab tshuaj lom thiab tsis muaj zog xws li methylene chloride, uas ua rau muaj kuab paug ib puag ncig.

Melt ester exchange method, tseem hu ua ontogenic polymerization, yog thawj zaug tsim los ntawm Bayer, siv molten bisphenol A thiab diphenyl carbonate (Diphenyl Carbonate, DPC), nyob rau hauv kub, siab nqus tsev vacuum, catalyst muaj lub xeev rau ester pauv, pre-condensation, condensation. tshuaj tiv thaiv.

Raws li cov khoom siv raw siv hauv DPC txheej txheem, nws tuaj yeem muab faib ua cov txheej txheem molten ester txauv (tseem hu ua indirect photogas method) thiab tsis yog-photogas molten ester exchange method.

2. Ib txwm molten ester pauv txoj kev

Nws muab faib ua 2 kauj ruam: (1) phosgene + phenol → DPC; (2) DPC + BPA → PC, uas yog cov txheej txheem phosgene indirect.

Cov txheej txheem yog luv luv, hnyav-dawb, thiab cov nqi tsim khoom qis dua me ntsis ntawm cov txheej txheem kev sib txuas ntawm phosgene, tab sis cov txheej txheem ntawm DPC tseem siv phosgene, thiab cov khoom DPC muaj cov kab ntawm cov chloroformate pawg, uas yuav cuam tshuam rau cov khoom kawg. qhov zoo ntawm PC, uas rau qee qhov txwv qhov kev txhawb nqa ntawm cov txheej txheem.

3. Tsis yog-phosgene molten ester txauv txoj kev

Txoj kev no muab faib ua 2 kauj ruam: (1) DMC + phenol → DPC; (2) DPC + BPA → PC, uas siv dimethyl carbonate DMC ua raw khoom thiab phenol los ua ke DPC.

Cov khoom lag luam phenol tau los ntawm kev sib pauv ester thiab condensation tuaj yeem rov ua dua rau kev sib txuas ntawm DPC txheej txheem, yog li paub txog cov khoom siv rov qab siv dua thiab kev lag luam zoo; vim lub siab purity ntawm raw cov ntaub ntawv, cov khoom kuj tsis tas yuav qhuav thiab ntxuav, thiab cov khoom zoo yog zoo. Cov txheej txheem tsis siv phosgene, yog ib puag ncig tus phooj ywg, thiab yog txoj hauv kev ntsuab.

Nrog rau lub teb chaws yuav tsum tau rau petrochemical tuam txhab uas muag 'peb pov tseg Nrog rau kev nce ntawm lub teb chaws txoj cai ntawm kev nyab xeeb thiab ib puag ncig tiv thaiv ntawm petrochemical tuam txhab uas muag thiab kev txwv ntawm kev siv phosgene, lub non-phosgene molten ester exchange technology yuav maj mam hloov lub interfacial polycondensation txoj kev nyob rau hauv lub yav tom ntej raws li cov kev taw qhia ntawm PC ntau lawm technology kev loj hlob nyob rau hauv lub ntiaj teb no.