Nā nīnau hoʻohālike a me ke kūkākūkā ʻana o nā hopena polymerization
He kumuhana koʻikoʻi nā hopena polymerization i ke kemika organik. Pili kēia kaʻina hana i ka hui ʻana o nā molekala monomer e hana i nā molekala nunui i kapa ʻia he polymers. He mea nui nā polymers i ke ola o kēlā me kēia lā, mai nā mea maka i hoʻohana ʻia e hana i nā plastics a me ka rubber a hiki i nā olonā lole. Ma kēia ʻatikala, e kūkākūkā mākou i kekahi mau laʻana o nā hopena polymerization a me kā lākou mau hopena.
Nā ʻano o ka Polymerization
Ma keʻano laulā, hiki ke puʻunaue ʻia ka polymerization i ʻelua mau ʻano nui:
1. Hoʻohui polymerization - Pili kēia kaʻina hana i ka hoʻohui ʻana i nā monomers e loaʻa ana nā pilina pālua a ʻekolu paha e hana i kahi polymer me ka ʻole o ka hana ʻana i nā huahana ʻaoʻao. ʻO kahi laʻana maʻamau o kahi polymer hoʻohui ʻo ia ka polyethylene, i hana ʻia mai ka ethylene (CH₂=CH₂).
2. Polymerization condensation - Ma kēia kaʻina hana, ʻo ka hopena ma waena o ʻelua monomers e loaʻa ana nā hui hana kikoʻī e hana i kahi polymer me nā huahana e like me ka wai a i ʻole methanol. ʻO kahi laʻana maʻamau ka nylon, i hana ʻia mai kahi diamine a me kahi diacid.
Laʻana o ka pilikia Polymerization Hoʻohui
Nīnau 1:
ʻO Ethylene (CH₂=CH₂) kahi monomer e polymerizes e hana i ka polyethylene. E wehewehe i ka hopena polymerization a hōʻike i nā huahana i loaʻa.
Kūkākūkā:
He polymer ka Polyethylene i hana ʻia mai nā monomers ethylene ma o kahi hopena polymerization hoʻohui. Hiki ke kākau ʻia kēia hopena penei:
\[ n \kikokikona{(CH₂=CH₂)} \rightarrow \kikokikona{ -[CH₂-CH₂]- }_n \]
Ma hea ʻo \(n \) ka helu o nā ʻāpana monomer. ʻO ka polyethylene i hoʻokumu ʻia he kaulahao lōʻihi o nā monomers ethylene me ka ʻole o nā huahana ʻaoʻao.
Nā nīnau hoʻohālike no ka polymerization condensation
Nīnau 2:
Hoʻokumu ʻia kahi polymer nylon-6,6 e ka hopena ma waena o hexamethylenediamine a me ka waikawa adipic. E kākau i ka hopena a papa inoa i nā huahana ʻaoʻao.
Kūkākūkā:
ʻO Nylon-6,6 kahi polymer i hoʻokumu ʻia mai ka hopena ma waena o hexamethylenediamine (\( \text{H₂N-(CH₂)₆-NH₂} \)) a me ka waikawa adipic (\( \text{HOOC-(CH₂)₄-COOH} \)). Hiki ke hoʻokumu ʻia ka hopena hoʻokumu penei:
\[ \text{n (H₂N-(CH₂)₆-NH₂) + n (HOOC-(CH₂)₄-COOH)} \arrow \text{ -[NH-(CH₂)₆-NH-CO-(CH₂)₄-CO]- }_n + 2n \text
ʻO ka huahana ʻaoʻao he wai (H₂O).
Nā Nīnau Polymerization ʻē aʻe
Nīnau 3:
Hoʻohana ʻia ka Polyethylene terephthalate (PET) i ka hana ʻana i nā ʻōmole palakiko a me nā lole. ʻO nā monomers e hana ana i ka PET ʻo ia ka ethylene glycol (\( \text{HOCH₂CH₂OH} \)) a me ka terephthalic acid (\( \text{HOOC-C₆H₄-COOH} \)). E wehewehe i ke kaʻina hana o ka hoʻokumu ʻana o PET a e helu i ka nui o ka huahana ʻaoʻao inā hoʻomaka mākou me 5 moles o kēlā me kēia monomer.
Kūkākūkā:
ʻO ke ʻano o ka hana polymerization condensation no ka hoʻokumu ʻana o PET penei:
\[ n \kikokikona{(HOCH₂CH₂OH)} + n \kikokikona{(HOOC-C₆H₄-COOH)} \rightarrow \kikokikona{ -[OOC-C₆H₄-COO-CH₂CH₂O]- }_n + 2n \kikokikona{H₂O} \]
Ma hea ʻo \(n \) ka helu o nā mole o ka monomer. Inā hoʻomaka mākou me 5 mole o ka ethylene glycol a me 5 mole o ka terephthalic acid, a laila ʻo nā huahana hopena he 5 × 2 = 10 mole o H₂O.
Nā ʻAoʻao Kinematic i ka Polymerization
I nā hopena polymerization, he mea nui ka noʻonoʻo ʻana i nā kinetics o ka hopena. Hiki ke hoʻopili ʻia ka wikiwiki o ka polymerization e nā kumu like ʻole e like me ka mahana, ke kaomi, a me ka nui o ka monomer.
Nīnau 4:
Inā ʻōlelo ʻia ka wikiwiki o ka polymerization o kahi hopena he \( k [M]^x \), kahi ʻo k ke kūpaʻa o ka wikiwiki, ʻo [M] ka nui o ka monomer, a ʻo x ke kauoha o ka hopena e pili ana i ka monomer, e wehewehe pehea e hoʻopilikia ai kahi loli i ka nui o ka monomer i ka wikiwiki o ka hopena inā x = 2.
Kūkākūkā:
Inā he 2 ʻo x, a laila ʻo ka wikiwiki o ka hopena he \( k [M]^2 \). ʻO ke ʻano kēia, ua kūlike pololei ka wikiwiki o ka hopena i ka huinahā o ka nui o ka monomer. Inā pāpālua ʻia ka nui o ka monomer, e piʻi aʻe ka wikiwiki o ka hopena i ʻehā manawa (2² = 4).
Hoʻohuihui Redox
ʻO kekahi ʻano hana polymerization ʻo ia ka redox polymerization. Pili kēia i kahi hana redox ma waena o ʻelua mau mea e hoʻomaka ai i ka polymerization.
Nīnau 5:
Hoʻokumu ʻia kahi polymer ma o kahi hopena redox ma waena o benzoyl peroxide a me styrene. E kākau i ka hopena hoʻomaka e hana ʻia.
Kūkākūkā:
ʻO ka hopena hoʻomaka ma waena o ka benzoyl peroxide a me ka styrene e hoʻopuka i nā radical manuahi e hoʻomaka ai i ka polymerization. Penei ka hopena:
\[ \kikokikona{(C₆H₅CO)₂O₂} \rightarrow 2 \kikokikona{C₆H₅COO·} \]
A laila hana ka benzoyloxyl radical (\( \text{C₆H₅COO·} \)) me ka styrene, e hoʻomaka ana i kahi hopena kaulahao o ka polymerization.
\[ \kikokikona{C₆H₅COO· + CH₂=CHC₆H₅} \rightarrow \kikokikona{C₆H₅COOCH₂-CH·C₆H₅} \]
Hoʻomau kēia hana a hiki i ka hana ʻana o ke koena o ka styrene i loko o ka ʻōnaehana e hana i ka polystyrene.
Ka hopena
He mea koʻikoʻi ka hoʻomaopopo ʻana i nā hopena polymerization a me nā ʻano hana ma hope o lākou no kekahi mea e pili ana i ka kemika a i ʻole ka ʻepekema mea. Me nā laʻana i kūkākūkā ʻia ma luna, manaʻo ʻia ka poʻe heluhelu e hoʻomaopopo i nā kaʻina hana kumu o ka hoʻohui a me ka condensation polymerization, a me kekahi mau ʻano holomua e like me ke kinetics reaction a me ka redox polymerization. Me kahi kahua paʻa, hiki iā mākou ke hoʻomaopopo maikaʻi i ke kuleana koʻikoʻi o nā polymers i nā ʻano like ʻole o ke ola hou.
