Nā nīnau hoʻohālike e kūkākūkā ana i ka hoʻohui ʻana i ka polymerization
ʻO ka polymerization ke kaʻina hana e hui pū ai nā monomers—nā molekala liʻiliʻi me nā ʻano like—e hana i nā molekala nui i kapa ʻia he polymers. ʻElua ʻano nui o ka polymerization: ka polymerization hoʻohui a me ka polymerization condensation. E kūkākūkā kēia ʻatikala i kekahi o kēia mau ʻano, ka polymerization hoʻohui, me ka hoʻoikaika ʻana i nā laʻana a me ke kūkākūkā ʻana e hāʻawi i kahi ʻike hohonu o kēia manaʻo.
Ke Hoʻomaopopo nei i ka Polymerization Hoʻohui
ʻO ka polymerization hoʻohui kahi hana e hui pū ai nā monomers me ka ʻole o ka nalowale ʻana o nā molekala liʻiliʻi e like me ka wai a i ʻole HCl. ʻO nā monomers i komo pinepine ʻia i ka polymerization hoʻohui he alkenes a me nā alkenes polarized, nona nā pilina pālua carbon-carbon (C=C). Ke pane kēia mau monomers, haki nā pilina pālua, e ʻae ana i nā monomers e hui pū i loko o nā kaulahao lōʻihi.
ʻO nā hiʻohiʻona o nā polymers i hana ʻia e ka polymerization hoʻohui ʻia e komo pū me ka polyethylene (PE), polypropylene (PP), polystyrene (PS), a me ka polyvinyl chloride (PVC). He mea nui kēia mau polymers a pau i ka ʻoihana a me ke ola o kēlā me kēia lā ma muli o ko lākou ikaika, kūpaʻa, a me nā ʻano hoʻohana like ʻole.
ʻAno Hana Polymerization Hoʻohui
Hiki ke hoʻokaʻawale ʻia ke ʻano polymerization hoʻohui i ʻekolu mau pae nui:
1. Hoʻomaka: ʻO ke kahua kahi e hoʻokumu ʻia ai nā radical manuahi a i ʻole nā iona e hoʻomaka i ka hopena.
2. Hoʻolaha: ʻO ke kahua kahi e hoʻomau ai nā monomers e hui pū e hana i nā kaulahao lōʻihi.
3. Hoʻopau: Ke kahua kahi e pau ai ka hopena ma muli o ka hui ʻana o ʻelua mau kaulahao radical manuahi a i ʻole ka hui ʻana o nā radical manuahi me kahi mea hoʻopaʻa.
I mea e akāka ai, eia kahi kūkākūkā ʻana o kekahi mau laʻana o nā nīnau polymerization hoʻohui.
Nā Nīnau Laʻana a me ke Kūkākūkā
Nīnau 1: Polymerization o Polyethylene
Nīnau: E wehewehe i ke kaʻina hana polymerization hoʻohui o ka ethylene (C2H4) e hana i ka polyethylene (PE), e hoʻokomo i ka hoohalike hopena e hana ʻia ana.
Kūkākūkā:
– Hoʻomaka:
Hiki ke hoʻokō ʻia ka hoʻomaka ʻana me ka hoʻohana ʻana i nā catalysts a i ʻole nā radicals manuahi. E noʻonoʻo kākou e hoʻohana ana mākou i nā radicals manuahi. Hiki i nā mea hoʻomaka radical e like me benzoyl peroxide (C14H10O4) ke hoʻokuʻu i nā radicals manuahi ke hoʻomehana ʻia.
\[
C14H10O4 \rightarrow 2C6H5COO^{\cdot}
\]
– Hoʻolaha:
E hoʻouka kēia mau radical i nā pilina pālua i loko o ka monomer ethylene, e hana ana i nā radical hou e hiki ke hoʻomau i ka hoʻouka ʻana i ka monomer e hiki mai ana.
\[
R^{\cdot} + CH2=CH2 \rightarrow R-CH2-CH2^{\cdot}
\]
ʻO ka mea aʻe, e hoʻomau nā radicals ma ka hopena o ke kaulahao i ka hoʻohui ʻana i nā monomers ethylene i lōʻihi ai ke kaulahao.
\[
R-CH2-CH2^{\cdot} + nCH2=CH2 \rightarrow R-(CH2-CH2)_n^{\cdot}
\]
– Hoʻopau ʻana:
Hiki ke hoʻopau ʻia ma o ka hui pū ʻana o ʻelua kaulahao radical a i ʻole ma o kahi hopena ma waena o kahi radical a me kahi mea hoʻopaʻa.
\[
R-(CH2-CH2)_n^{\cdot} + R-(CH2-CH2)_m^{\cdot} \rightarrow R-(CH2-CH2)_{n+m}-R
\]
ʻO ka hopena hope loa he polyethylene (PE), kahi polymer i hana ʻia ma ka hoʻohui ʻana i nā monomers ethylene he nui (\(n\) ethylene).
Nīnau 2: Polymerization o Polystyrene
Nīnau: Makemake kahi ʻoihana kemika e hana i kahi polymer mai ka monomer styrene (C8H8). E wehewehe i ka hopena polymerization e hana ʻia a kākau i ke ʻano o ka polystyrene.
Kūkākūkā:
– Hoʻomaka:
E like me ka polyethylene, pono nā radical manuahi e hoʻomaka i ka hopena. E ʻōlelo kākou e hoʻohana mākou i nā radical peroxide.
\[
ROOR \rightarrow 2RO^{\cdot}
\]
– Hoʻolaha:
Hoʻouka nā radical manuahi i nā monomers styrene nona nā pilina pālua carbon-carbon.
\[
RO^{\cdot} + C6H5-CH=CH2 \rightarrow RO-C6H5-CH^{\cdot}-CH3
\]
ʻO ke kahua hoʻolaha e lawe mai i kēia mau radical e hoʻomau i ka hoʻouka ʻana i nā monomers styrene ʻē aʻe.
\[
RO-C6H5-CH^{\cdot}-CH3 + n(C6H5-CH=CH2) \rightarrow RO-(C6H5-CH-CH2)_n-C6H5-CH^{\cdot}-CH3
\]
– Hoʻopau ʻana:
Hoʻopau ʻia ka wā e hui ai ʻelua mau kaulahao polymer radical.
\[
RO-(C6H5-CH-CH2)_n^{\cdot} + RO-(C6H5-CH-CH2)_m^{\cdot} \rightarrow RO-(C6H5-CH-CH2)_{n+m}-RO
\]
ʻO ka hopena o ka polystyrene (PS) he kaulahao lōʻihi i hana ʻia me nā ʻāpana styrene monomer e hana hou ʻia ana.
Nīnau 3: Polymerization o Polyvinyl Chloride (PVC)
Nīnau: E wehewehe i ka polymerization hoʻohui o ka vinyl chloride monomer (C2H3Cl), a hāʻawi i nā laʻana o nā noi o ka polyvinyl chloride (PVC).
Kūkākūkā:
– Hoʻomaka:
E like me ke ʻano ma mua, ua hana ʻia nā radical manuahi mai nā peroxides.
\[
ROOR \rightarrow 2R-O^{\cdot}
\]
– Hoʻolaha:
Hoʻouka nā radical manuahi i nā pilina pālua i nā monomers vinyl chloride.
\[
RO^{\cdot} + CH2=CHCl \rightarrow RO-CH2-CHCl^{\cdot}
\]
Hoʻomau ka hoʻolaha ʻana me nā ʻāpana monomer e hui pū ana e hoʻolōʻihi i ke kaulahao.
\[
RO-CH2-CHCl^{\cdot} + nCH2=CHCl \rightarrow RO-(CH2-CHCl)_n^{\cdot}
\]
– Hoʻopau ʻana:
Hoʻopau ʻia ka hoʻopau ʻana ke hui pū ʻia nā kaulahao radical ʻelua.
\[
RO-(CH2-CHCl)_n^{\cdot} + RO-(CH2-CHCl)_m^{\cdot} \rightarrow RO-(CH2-CHCl)_{n+m}-RO
\]
ʻO ka Polyvinyl chloride (PVC) kahi polymer i hana ʻia a hoʻohana ʻia i nā ʻano hana like ʻole e like me nā paipu wai, nā kaula uila, a me nā huahana plastik like ʻole.
Ka hopena
He hana kemika koʻikoʻi ka polymerization hoʻohui e pili ana i ka hui pū ʻana o nā monomers me ka ʻole o ka hoʻokuʻu ʻia ʻana o nā mole liʻiliʻi. ʻO ka hoʻomaopopo ʻana i nā ʻano hana a me nā hopena o ka polymerization hoʻohui, e like me nā mea i ʻike ʻia ma ka polyethylene, polystyrene, a me PVC, kōkua iā mākou e aʻo a hoʻopili i kēia ʻike ma ka ʻoihana a me ke ola o kēlā me kēia lā. Ma o kēia mau laʻana a me nā kūkākūkā ʻana, hiki iā mākou ke loaʻa kahi ʻike hohonu o nā kaʻina hana a me nā huahana i loaʻa mai ka polymerization hoʻohui, a me kāna mau noi hana e hoʻopilikia i ka ʻenehana a me ke ola hou.
