Imibuzo Yesibonelo Ekhuluma Ngokuhlanganisa I-Polymerization
I-polymerization inqubo lapho ama-monomers—ama-molecule amancane anezakhiwo ezifanayo—ahlangana khona ukuze akhe ama-molecule amakhulu abizwa ngokuthi ama-polymer. Kunezinhlobo ezimbili eziyinhloko ze-polymerization: i-polymerization yokwengeza kanye ne-polymerization ye-condensation. Lesi sihloko sizoxoxa ngolunye lwalezi zinhlobo, i-polymerization yokwengeza, ngokugcizelela ezibonelweni kanye nengxoxo ukuze kunikezwe ukuqonda okujulile kwalomqondo.
Ukuqonda i-Add Polymerization
Ukwengeza i-polymerization kuyinqubo lapho ama-monomer ehlangana khona ngaphandle kokulahlekelwa ama-molecule amancane njengamanzi noma i-HCl. Ama-monomer avame ukuhileleka ekuhlanganiseni i-polymerization ama-alkenes nama-alkenes ahlukaniswe ngama-polarized, anezibopho ezimbili ze-carbon-carbon (C=C). Lapho la ma-monomer esabela, izibopho ezimbili ziyaphuka, okuvumela ama-monomer ukuthi ahlangane abe amaketanga amade.
Izibonelo zama-polymer akhiqizwa ngokufaka i-polymerization eyengeziwe zifaka phakathi i-polyethylene (PE), i-polypropylene (PP), i-polystyrene (PS), kanye ne-polyvinyl chloride (PVC). Wonke la ma-polymer abalulekile embonini nasempilweni yansuku zonke ngenxa yamandla awo, ukuzinza, kanye nokusetshenziswa okubanzi.
Indlela Yokwengeza I-Polymerization
Indlela yokwenza i-polymerization yokwengeza ingahlukaniswa ngezigaba ezintathu eziyinhloko:
1. Ukuqaliswa: Isigaba lapho kwakheka khona ama-free radical noma ama-ion ukuqala ukusabela.
2. Ukusabalala: Isigaba lapho ama-monomer eqhubeka nokuhlangana khona ukuze akhe amaketanga amade.
3. Ukuphela: Isigaba lapho ukusabela kuphela khona ngoba amaketanga amabili e-free radical ahlangana noma ama-free radical ahlangana nesithiyo.
Ukuze kucace, nansi ingxoxo yezibonelo eziningana zemibuzo yokwengeza i-polymerization.
Imibuzo Eyisibonelo Nengxoxo
Umbuzo 1: Ukwenziwa kwe-Polyethylene ibe yi-polymer
Umbuzo: Chaza inqubo yokufaka i-polymerization ye-ethylene (C2H4) ukuze kwakheke i-polyethylene (PE), faka i-reaction equation eyenzeka.
Ingxoxo:
- Ukuqaliswa:
Ukuqaliswa kungafezwa kusetshenziswa ama-catalyst noma ama-free radical. Ake sithi sisebenzisa ama-free radical. Ama-radical initiators afana ne-benzoyl peroxide (C14H10O4) angakhipha ama-free radical uma eshiswa.
\[
C14H10O4 \rightarrow 2C6H5COO^{\cdot}
\]
- Ukusabalala:
Lawa ma-radical azohlasela izibopho ezimbili ku-ethylene monomer, akhiqize ama-radical amasha angaqhubeka nokuhlasela i-monomer elandelayo.
\[
R^{\cdot} + CH2=CH2 \umcibisholo ongakwesokudla R-CH2-CH2^{\cdot}
\]
Okulandelayo, ama-radical ekugcineni kochungechunge azoqhubeka nokwengeza ama-ethylene monomers ukuze uchungechunge lube lude.
\[
R-CH2-CH2^{\cdot} + nCH2=CH2 \rightarrow R-(CH2-CH2)_n^{\cdot}
\]
- Ukuphela:
Ukuqedwa kungenzeka ngokuhlanganiswa kwamaketanga amabili ama-radical noma ngokusabela phakathi kwe-radical kanye ne-inhibitor.
\[
R-(CH2-CH2)_n^{\cdot} + R-(CH2-CH2)_m^{\cdot} \rightarrow R-(CH2-CH2)_{n+m}-R
\]
Umphumela wokugcina uba yi-polyethylene (PE), i-polymer ekhiqizwa ngokuhlanganisa ama-ethylene monomers amaningi (\(n\) ethylene).
Umbuzo 2: Ukwenziwa kwe-Polystyrene ibe yi-polymer
Umbuzo: Imboni yamakhemikhali ifuna ukukhiqiza i-polymer evela ku-monomer styrene (C8H8). Chaza ukusabela kwe-polymerization okwenzekayo bese ubhala isakhiwo se-polystyrene.
Ingxoxo:
- Ukuqaliswa:
Njengoba kunjalo nge-polyethylene, ama-free radicals ayadingeka ukuqala ukusabela. Ake sithi sisebenzisa ama-peroxide radicals.
\[
UMGWAQO \umcibisholo ongakwesokudla 2RO^{\cdot}
\]
- Ukusabalala:
Ama-free radical ahlasela ama-styrene monomers anezibopho ezimbili ze-carbon-carbon.
\[
RO^{\cdot} + C6H5-CH=CH2 \umcibisholo ongakwesokudla RO-C6H5-CH^{\cdot}-CH3
\]
Isigaba sokusabalala sizoletha la ma-radical ukuthi aqhubeke nokuhlasela amanye ama-monomer e-styrene.
\[
RO-C6H5-CH^{\cdot}-CH3 + n(C6H5-CH=CH2) \rightarrow RO-(C6H5-CH-CH2)_n-C6H5-CH^{\cdot}-CH3
\]
- Ukuphela:
Ukuqedwa kwenzeka lapho amaketanga amabili e-polymer ahlangana.
\[
RO-(C6H5-CH-CH2)_n^{\cdot} + RO-(C6H5-CH-CH2)_m^{\cdot} \rightarrow RO-(C6H5-CH-CH2)_{n+m}-RO
\]
Isakhiwo se-polystyrene (PS) esiphumelayo siyiketanga elide eliqukethe amayunithi e-styrene monomer aphindaphindayo.
Umbuzo 3: Ukwenziwa kwe-Polyvinyl Chloride (PVC) kube yi-polymerization
Umbuzo: Chaza i-polymerization eyengeziwe ye-vinyl chloride monomer (C2H3Cl), bese unikeza izibonelo zokusetshenziswa kwe-polyvinyl chloride (PVC).
Ingxoxo:
- Ukuqaliswa:
Njengesibonelo esidlule, ama-free radical akhiqizwa ngama-peroxide.
\[
UMGWAQO \umcibisholo ongakwesokudla 2R-O^{\cdot}
\]
- Ukusabalala:
Ama-free radical ahlasela ama-double bond kuma-vinyl chloride monomers.
\[
RO^{\cdot} + CH2=CHCl \umcibisholo ongakwesokudla RO-CH2-CHCl^{\cdot}
\]
Ukusabalala kuyaqhubeka ngamayunithi e-monomer ahlangana ukuze kwandiswe uchungechunge.
\[
RO-CH2-CHCl^{\cdot} + nCH2=CHCl \rightarrow RO-(CH2-CHCl)_n^{\cdot}
\]
- Ukuphela:
Ukuqedwa kwenzeka lapho izintambo ezimbili ezinkulu zihlangana.
\[
RO-(CH2-CHCl)_n^{\cdot} + RO-(CH2-CHCl)_m^{\cdot} \umugqa ongakwesokudla RO-(CH2-CHCl)_{n+m}-RO
\]
I-Polyvinyl chloride (i-PVC) iyi-polymer ekhiqizwa futhi isetshenziswe ezinhlotsheni ezahlukene ezifana namapayipi amanzi, izintambo zikagesi, kanye neminye imikhiqizo ehlukahlukene yepulasitiki.
Isiphetho
Ukwengeza i-polymerization kuyinqubo ebalulekile yamakhemikhali ehilela ukuhlanganiswa kwama-monomers ngaphandle kokukhululwa kwama-molecule amancane. Ukuqonda izindlela kanye nokusabela kwe-polymerization yokwengeza, njengaleyo ebonakala ku-polyethylene, i-polystyrene, kanye ne-PVC, kusisiza ukuthi sifunde futhi sisebenzise lolu lwazi embonini nasempilweni yansuku zonke. Ngalezi zibonelo nezingxoxo, singathola ukuqonda okujulile kwezinqubo nemikhiqizo ebangelwa ukwengeza i-polymerization, kanye nezicelo zayo ezisebenzayo ezithinta ubuchwepheshe kanye nokuphila kwanamuhla.
