Ngā Tauira Pātai me te Kōrero mō ngā Tauhohenga Polymerization
He kaupapa matua ngā tauhohenga polymerization i roto i te matū waro. Kei roto i tēnei tukanga te hononga o ngā ngota monomer hei hanga i ngā ngota nunui e kiia nei ko ngā polymer. He mea nui ngā polymer ki te oranga o ia rā, mai i ngā rauemi mata e whakamahia ana hei hanga kirihou me te rapa ki ngā muka kakahu. I roto i tēnei tuhinga, ka matapakihia e mātou ētahi tauira o ngā tauhohenga polymerization me ō rātou otinga.
Ngā momo whakapūhui
I te nuinga o te wā, ka taea te wehewehe i te polymerization ki ngā momo matua e rua:
1. Te whakakotahitanga tāpiritanga – Ko tēnei tukanga e uru ana ki te whakakotahi i ngā monomer kei roto ngā hononga takirua, takitoru rānei hei hanga i tētahi polymer me te kore e puta he hua taha. Ko tētahi tauira noa o te polymer tāpiritanga ko te polyethylene, i hangaia mai i te ethylene (CH₂=CH₂).
2. Te whakapūhuitanga o te konupūmā – I roto i tēnei tukanga, ko te tauhohenga i waenga i ngā monomer e rua kei roto ngā rōpū mahi motuhake ka puta he polymer me ngā hua taha pēnei i te wai, te methanol rānei. Ko tētahi tauira noa ko te nairona, i hangaia mai i te diamine me te diacid.
Tauira o te Raru Whakapūhui Tāpiri
Pātai 1:
Ko te Ethylene (CH₂=CH₂) he monomer e whakapūhui ana hei hanga polyethylene. Whakaahuahia te tauhohenga whakapūhui, me ngā hua ka puta.
Kōrero:
He pūhui te polyethylene i hangaia mai i ngā monomer ethylene mā te tauhohenga tāpiri polymerization. Ka taea te tuhi i tēnei tauhohenga penei:
\[ n \kuputuhi{(CH₂=CH₂)} \pere matau \kuputuhi{ -[CH₂-CH₂]- }_n \]
Ko \( n \) te maha o ngā waeine monomer. Ko te polyethylene i hangaia he mekameka roa o ngā monomer ethylene, kāore he hua taha.
Ngā Tauira Pātai mō te Whakapūhuitanga Whakatōtō
Pātai 2:
Ka hangaia he pūhui nairona-6,6 mā te tauhohenga i waenga i te hexamethylenediamine me te waikawa adipic. Tuhia te tauhohenga, ka whakarārangihia ngā hua taha.
Kōrero:
Ko te Nylon-6,6 he pūmua i hangaia mai i te tauhohenga i waenga i te hexamethylenediamine (\( \text{H₂N-(CH₂)₆-NH₂} \)) me te waikawa adipic (\( \text{HOOC-(CH₂)₄-COOH} \)). Ka taea te whakatakoto i te tauhohenga hanganga penei:
\[ \text{n (H₂N-(CH₂)₆-NH₂) + n (HOOC-(CH₂)₄-COOH)} \perematau \text{ -[NH-(CH₂)₆-NH-CO-(CH₂)₄-CO]- }_n + 2n \text
Ko te hua taha ko te wai (H₂O).
Ētahi atu Pātai Whakapūhui
Pātai 3:
Ka whakamahia te polyethylene terephthalate (PET) i roto i te hanga i ngā pounamu kirihou me ngā papanga. Ko ngā monomer e hanga ana i te PET ko te ethylene glycol (\( \text{HOCH₂CH₂OH} \)) me te waikawa terephthalic (\( \text{HOOC-C₆H₄-COOH} \)). Whakamāramahia te tukanga o te hanganga PET, ā, tatauhia te nui o te hua taha mēnā ka tīmata tātou me te 5 mole o ia monomer.
Kōrero:
Ko te tauhohenga polymerization condensation mō te hanganga o te PET ko:
\[ n \kuputuhi{(HOCH₂CH₂OH)} + n \kuputuhi{(HOOC-C₆H₄-COOH)} \rightarrow \kuputuhi{ -[OOC-C₆H₄-COO-CH₂CH₂O]- }_n + 2n \kuputuhi{H₂O} \]
Ko \( n \) te maha o ngā mole o te monomer. Mēnā ka tīmata tātou me te 5 mole o te ethylene glycol me te 5 mole o te waikawa terephthalic, ko ngā hua taha ko te 5 × 2 = 10 mole o te H₂O.
Ngā Āhuatanga Kinematic i roto i te Polymerization
I roto i ngā tauhohenga polymerization, he mea nui te whakaaro ki te tere o te tauhohenga. Ka taea te awe i te tere polymerization e ngā āhuatanga maha pēnei i te pāmahana, te pēhanga, me te kukū o te monomer.
Pātai 4:
Mena ka kiia te tere o te whakapūhui o tētahi tauhohenga ko \( k [M]^x \), ko k te pūmau tere, ko [M] te kukū o te monomer, ā, ko x te raupapa o te tauhohenga e pā ana ki te monomer, whakamāramahia me pēhea te pānga o te huringa o te kukū o te monomer ki te tere tauhohenga mena ko x = 2.
Kōrero:
Mena ko x he 2, ko te tere o te tauhohenga ko \( k [M]^2 \). Ko te tikanga o tēnei he rite tonu te tere o te tauhohenga ki te tapawhā o te kukū o te monomer. Mena ka takiruahia te kukū o te monomer, ka piki ake te tere o te tauhohenga kia whā ngā wā (2² = 4).
Te Whakapūhuitanga Redox
Ko tētahi atu momo tauhohenga polymerization ko te redox polymerization. Kei roto i tēnei he tauhohenga redox i waenga i ngā matū e rua e tīmata ana i te polymerization.
Pātai 5:
Ka hangaia he pūmua mā te tauhohenga redox i waenga i te benzoyl peroxide me te styrene. Tuhia te tauhohenga tīmatanga e puta ana.
Kōrero:
Ko te tauhohenga tīmatanga i waenga i te benzoyl peroxide me te styrene ka puta he rauropi kore utu e tīmata ai te polymerization. Ko te tauhohenga e whai ake nei:
\[ \kuputuhi{(C₆H₅CO)₂O₂} \rightarrow 2 \kuputuhi{C₆H₅COO·} \]
Kātahi ka tauhohe te rauropi benzoyloxyl (\( \text{C₆H₅COO·} \)) ki te styrene, ka tīmata ai he tauhohenga mekameka o te polymerization.
\[ \kuputuhi{C₆H₅COO· + CH₂=CHC₆H₅} \rightarrow \kuputuhi{C₆H₅COOCH₂-CH·C₆H₅} \]
Ka haere tonu tēnei tauhohenga kia tauhohe rā anō te toenga o te styrene i roto i te pūnaha hei hanga i te polystyrene.
Whakamutunga
He mea nui te mārama ki ngā tauhohenga polymerization me ngā tikanga kei muri i aua tauhohenga mō te hunga katoa e uru ana ki te matū, ki te pūtaiao rauemi rānei. Mā ngā tauira kua kōrerotia i runga ake nei, e tumanakohia ana kia mārama ngā kaipānui ki ngā tukanga taketake o te polymerization tāpiri me te condensation, tae atu ki ētahi āhuatanga matatau pērā i te kinetics tauhohenga me te polymerization redox. Mā te pūtake pakari, ka taea e tātou te mārama ake ki te tūranga nui o ngā polymer i roto i ngā āhuatanga maha o te ao hou.
