ʻAno hana o ka hana hoʻopaʻa PVC

ʻO ke kumu nui o ka hōʻino ʻia ʻana o ka PVC ʻo ia ka hoʻopau ʻana o nā ʻātoma chlorine ikaika i loko o ka molekala ma lalo o ka hoʻomehana ʻana a me ka oxygen, e hopena ana i ka hana ʻana o HCI. No laila, ʻo nā mea hoʻopaʻa wela PVC he mau hui nui e hiki ke hoʻopaʻa i nā ʻātoma chlorine i loko o nā molekala PVC a pale a ʻae paha i ka hoʻokuʻu ʻia ʻana o HCI. Ua hoʻokaʻawale ʻo R. Gachter et al. i nā hopena o nā mea hoʻopaʻa wela ma ke ʻano he pale a me ka hoʻoponopono. Loaʻa i ka mea mua nā hana o ka omo ʻana i ka HCI, ka hoʻololi ʻana i nā ʻātoma chlorine paʻa ʻole, ka hoʻopau ʻana i nā kumu hoʻā, a me ka pale ʻana i ka oxidation aunoa. ʻO ke ʻano hoʻoponopono hope e manaʻo e hoʻohui i ka ʻano polyene, e pane me nā ʻāpana unsaturated i loko o PVC, a luku i nā carbocations. ʻO ke ʻano kikoʻī, penei:

(1) Hoʻomoʻa i ka HC1 i unuhi ʻia mai ka PVC e kāohi i kāna hana catalytic ponoʻī. Hiki i nā huahana e like me nā paʻakai kēpau, nā kopa metala waikawa organik, nā hui organotin, nā hui epoxy, nā amines, nā alkoxides metala a me nā phenols, a me nā thiols metala ke hana pū me HCI e kāohi i ka hana de HCI o PVC.

ʻO wau (RCOO) 2+2HCI MeCl+2RCOOH

(2) E hoʻololi a hoʻopau paha i nā mea paʻa ʻole e like me nā ʻātoma allyl chloride a i ʻole nā ​​ʻātoma carbon chloride tertiary i loko o nā molekala PVC, a hoʻopau i ke kiko hoʻomaka o ka wehe ʻana o HCI. Inā hoʻohui nā ʻātoma tin o nā mea hoʻopaʻa tin organik me nā ʻātoma chlorine paʻa ʻole o nā molekala PVC, a hoʻohui nā ʻātoma sulfur i loko o ka tin organik me nā ʻātoma kalapona e pili ana i ka PVC, e hoʻololi nā ʻātoma sulfur i loko o ke kino hoʻohui me nā ʻātoma chlorine paʻa ʻole. Ke loaʻa ka HC1, māhele ka pilina hoʻohui, a hoʻopaʻa paʻa ka hui hydrophobic me nā ʻātoma kalapona i loko o nā molekala PVC, a laila e pale ana i nā hopena hou aʻe o ka wehe ʻana o HCI a me ka hoʻokumu ʻana o nā pilina pālua. Ma waena o nā kopa metala, ʻo ka kopa zinc a me ke kopa ipu ka hopena pani wikiwiki loa me nā ʻātoma chlorine paʻa ʻole, ʻo ke kopa barium ka lohi loa, ʻoi aku ka lohi o ke kopa calcium, a aia ke kopa kēpau ma waena. I ka manawa like, he ʻokoʻa nā pae o ka hopena catalytic o nā chloride metala i hana ʻia i ka wehe ʻana o HCI, a penei ko lākou ikaika:

Hoʻohui ʻia ʻo ZnCl>CdCl>>BaCl, CaCh>R2SnCl2 (3) i nā pilina pālua a me nā pilina pālua i hoʻohui ʻia e pale aku i ka hoʻomohala ʻana o nā ʻano polyene a hōʻemi i ke kala. Loaʻa i nā paʻakai waikawa unsaturated a i ʻole nā ​​​​​​hui nā pilina pālua, kahi e hana ai i kahi hopena hoʻohui diene me nā molekala PVC, a laila e hoʻopilikia ana i ko lākou ʻano covalent a pale i ka hoʻololi kala. Eia kekahi, hele pū ʻia ke kopa metala me ka hoʻoili pilina pālua i ka wā e pani ana i ka allyl chloride, e hōʻino ana i ka ʻano polyene a pēlā e pale ai i ka hoʻololi kala.

(4) Hopu i nā radical manuahi e pale aku i ka oxidation aunoa. Inā hiki i ka hoʻohui ʻana i nā mea hoʻopaʻa wela phenolic ke ālai i ka wehe ʻana o HC1, no ka mea hiki i nā radical manuahi atom hydrogen i hāʻawi ʻia e nā phenols ke hui pū me nā radical manuahi macromolecular PVC i hoʻohaʻahaʻa ʻia, e hana ana i kahi mea hiki ʻole ke pane me ka oxygen a loaʻa ka hopena hoʻopaʻa wela. Hiki i kēia mea hoʻopaʻa wela ke loaʻa i hoʻokahi a ʻoi aku paha nā hopena.