Imibuzo Yesibonelo kanye Nengxoxo Yezimpendulo Ze-Polymerization
Ukusabela kwe-polymerization kuyisihloko esibalulekile kumakhemikhali e-organic. Le nqubo ihilela ukuhlanganiswa kwama-molecule e-monomer ukwakha ama-molecule amakhulu abizwa ngokuthi ama-polymer. Ama-polymer abalulekile empilweni yansuku zonke, kusukela ezintweni zokusetshenziswa ezisetshenziswa ukwenza amapulasitiki nerabha kuya kuma-fiber endwangu. Kulesi sihloko, sizoxoxa ngezibonelo eziningana zokusabela kwe-polymerization kanye nezixazululo zazo.
Izinhlobo ze-Polymerization
Ngokuvamile, i-polymerization ingahlukaniswa ngezinhlobo ezimbili eziyinhloko:
1. Ukwengeza i-polymerization – Le nqubo ihilela ukuhlanganisa ama-monomer aqukethe izibopho ezimbili noma ezintathu ukwakha i-polymer ngaphandle kokukhiqiza imikhiqizo elandelanayo. Isibonelo esivamile se-polymer eyengeziwe yi-polyethylene, eyakhiwa nge-ethylene (CH₂=CH₂).
2. Ukwakheka kwe-condensation polymerization – Kule nqubo, ukusabela phakathi kwama-monomer amabili aqukethe amaqembu athile asebenzayo kukhiqiza i-polymer kanye nemikhiqizo efana namanzi noma i-methanol. Isibonelo esivamile yi-nylon, eyakhiwa nge-diamine kanye ne-diacid.
Isibonelo Senkinga Yokwengeza I-Polymerization
Umbuzo 1:
I-Ethylene (CH₂=CH₂) iyi-monomer e-polymerizes ukuze yakhe i-polyethylene. Chaza ukusabela kwe-polymerizes bese usho imikhiqizo ephumayo.
Ingxoxo:
I-Polyethylene iyi-polymer eyakhiwe ngama-ethylene monomers ngokusebenzisa ukusabela kwe-polymerization eyengeziwe. Lokhu kusabela kungabhalwa kanje:
\[ n \text{(CH₂=CH₂)} \rightarrow \text{ -[CH₂-CH₂]- }_n \]
Lapho \( n \) kuyinani lamayunithi e-monomer. I-polyethylene eyakhiwe iyiketanga elide lama-monomer e-ethylene angenazo ezinye izinto eziphuma kuyo.
Imibuzo Yesibonelo Sokupholisha Ukupholisha
Umbuzo 2:
I-polymer ye-nylon-6,6 yakhiwa ukusabela phakathi kwe-hexamethylenediamine ne-adipic acid. Bhala ukusabela bese ubhala uhlu lwemikhiqizo engezansi.
Ingxoxo:
I-Nylon-6,6 iyi-polymer eyakhiwe kusukela ekusabeleni phakathi kwe-hexamethylenediamine (\( \text{H₂N-(CH₂)₆-NH₂} \)) kanye ne-adipic acid (\( \text{HOOC-(CH₂)₄-COOH} \)). Ukusabela kokwakheka kungakhiwa kanje:
\[ \umbhalo{n (H₂N-(CH₂)₆-NH₂) + n (HOOC-(CH₂)₄-COOH)} \umcibisholo ongakwesokudla \umbhalo{ -[NH-(CH₂)₆-NH-CO-(CH₂)₄-CO]- }_n{} + 2n \umbhalo
Umkhiqizo osele ngemuva kwawo ngamanzi (H₂O).
Eminye Imibuzo Yokwenza I-Polymerization
Umbuzo 3:
I-Polyethylene terephthalate (PET) isetshenziswa ekwenziweni kwamabhodlela epulasitiki nezindwangu. Ama-monomer akha i-PET yi-ethylene glycol (\( \text{HOCH₂CH₂OH} \)) kanye ne-terephthalic acid (\( \text{HOOC-C₆H₄-COOH} \)). Chaza inqubo yokwakheka kwe-PET bese ubala inani lomkhiqizo olandelanayo uma siqala ngama-mole ama-5 e-monomer ngayinye.
Ingxoxo:
Ukusabela kwe-polymerization ye-condensation yokwakheka kwe-PET yilokhu:
\[ n \text{(HOCH₂CH₂OH)} + n \text{(HOOC-C₆H₄-COOH)} \rightarrow \text{ -[OOC-C₆H₄-COO-CH₂CH₂O]- }_n + 2n \text{H₂O} \]
Lapho \( n \) kuyinani lama-moles e-monomer. Uma siqala ngama-moles ama-5 e-ethylene glycol kanye nama-moles ama-5 e-terephthalic acid, khona-ke imikhiqizo elandelanayo ingu-5 × 2 = 10 ama-moles e-H₂O.
Izici ze-Kinematic ku-Polymerization
Ekuphenduleni kwe-polymerization, i-reaction kinetics iyinto ebalulekile okufanele icatshangelwe. Izinga le-polymerization lingathonywa yizici ezahlukahlukene njengokushisa, ingcindezi, kanye nokuhlushwa kwe-monomer.
Umbuzo 4:
Uma izinga lokwenziwa kwe-polymerization yokusabela kuthiwa yi-\( k [M]^x \), lapho u-k eyisilinganiselo esingaguquki, u-[M] uyisilinganiso se-monomer, kanti u-x uyi-oda lokusabela maqondana ne-monomer, chaza ukuthi ushintsho ekugxilweni kwe-monomer luzothinta kanjani izinga lokusabela uma u-x = 2.
Ingxoxo:
Uma u-x engu-2, khona-ke izinga lokusabela lingu-\( k [M]^2 \). Lokhu kusho ukuthi izinga lokusabela lilingana ngqo nesikwele sokuhlushwa kwe-monomer. Uma ukuhlushwa kwe-monomer kuphindwe kabili, izinga lokusabela lizokhuphuka kane (2² = 4).
Ukwenziwa kwe-Redox Polymerization
Olunye uhlobo lokusabela kwe-polymerization yi-redox polymerization. Lokhu kuhilela ukusabela kwe-redox phakathi kwezinto ezimbili eziqala i-polymerization.
Umbuzo 5:
I-polymer yakhiwa ngokusabela kwe-redox phakathi kwe-benzoyl peroxide ne-styrene. Bhala ukusabela kokuqala okwenzekayo.
Ingxoxo:
Ukusabela kokuqala phakathi kwe-benzoyl peroxide ne-styrene kukhiqiza ama-free radicals aqala i-polymerization. Ukusabela okulandelayo:
\[ \text{(C₆H₅CO)₂O₂} \rightarrow 2 \text{C₆H₅COO·} \]
I-benzoyloxyl radical (\( \text{C₆H₅COO·} \)) bese isabela ne-styrene, iqale ukusabela kwe-chain of polymerization.
\[ \text{C₆H₅COO· + CH₂=CHC₆H₅} \rightarrow \text{C₆H₅COOCH₂-CH·C₆H₅} \]
Lokhu kusabela kuyaqhubeka kuze kube yilapho i-styrene esele ohlelweni isisabela ekwakhekeni kwe-polystyrene.
Isiphetho
Ukuqonda ukusabela kwe-polymerization kanye nezindlela ezingemuva kwayo kubalulekile kunoma ngubani ohilelekile kumakhemikhali noma kwisayensi yezinto ezibonakalayo. Ngezibonelo okuxoxwe ngazo ngenhla, abafundi kulindeleke ukuthi baqonde izinqubo eziyisisekelo ze-polymerization yokwengeza kanye ne-condensation, kanye nezici ezithile ezithuthukile njenge-reaction kinetics kanye ne-redox polymerization. Ngesisekelo esiqinile, singayiqonda kangcono indima ebalulekile yama-polymers ezicini ezahlukene zokuphila kwanamuhla.
