Mibvunzo yeMienzaniso neKukurukurirana kweMagadzirirwo ePolymerization
Maitiro epolymerization inyaya huru mu organic chemistry. Maitiro aya anosanganisira kubatanidzwa kwemamonomer molecules kuti aumbe mamorekuru makuru anonzi mapolymers. Mapolymers akakosha muhupenyu hwezuva nezuva, kubva pazvinhu zvinoshandiswa kugadzira mapurasitiki nerabha kusvika kumachira ejira. Muchinyorwa chino, tichakurukura mienzaniso yakati wandei yemaitiro epolymerization uye mhinduro dzawo.
Mhando dzePolymerization
Kazhinji, polymerization inogona kukamurwa kuita mhando mbiri huru:
1. Kuwedzera polymerization - Maitiro aya anosanganisira kubatanidza ma monomers ane ma bond maviri kana matatu kuti agadzire polymer pasina kugadzira zvimwe zvigadzirwa. Muenzaniso wakajairika wekuwedzera polymer i polyethylene, iyo inoumbwa kubva ku ethylene (CH₂=CH₂).
2. Kugadziriswa kwemvura inodziya – Mukuita uku, maitiro ari pakati pemamonomeri maviri ane mapoka anoshanda anogadzira polymer pamwe chete nezvigadzirwa zvakaita semvura kana methanol. Muenzaniso wakajairika inylon, iyo inoumbwa kubva kudiamine nediacid.
Muenzaniso weDambudziko rekuwedzera Polymerization
Mubvunzo 1:
Ethylene (CH₂=CH₂) imonomer inopomera kuita polyethylene. Tsanangura maitiro epomeralization uye taura zvigadzirwa zvinobva.
Kukurukurirana:
Polyethylene ipolymer inoumbwa kubva ku ethylene monomers kuburikidza ne addition polymerization reaction. Iyi reaction inogona kunyorwa seinotevera:
\[ n \text{(CH₂=CH₂)} \rightarrow \text{ -[CH₂-CH₂]- }_n \]
Apo \( n \) iri nhamba yemayuniti emonomer. Polyethylene inoumbwa iketani refu yemamonomer e-ethylene isina zvimwe zvinobuda.
Muenzaniso weCondensation Polymerization Mibvunzo
Mubvunzo 2:
Polymer yenylon-6,6 inoumbwa nekuita pakati pehexamethylenediamine neadipic acid. Nyora maitiro acho wonyora zvabuda.
Kukurukurirana:
Nylon-6,6 ipolymer yakagadzirwa kubva pakusangana pakati pehexamethylenediamine (\( \text{H₂N-(CH₂)₆-NH₂} \)) uye adipic acid (\( \text{HOOC-(CH₂)₄-COOH} \)). Kusangana kwekuumbwa kunogona kuumbwa seizvi:
\[ \zvinyorwa{n (H₂N-(CH₂)₆-NH₂) + n (HOOC-(CH₂)₄-COOH)} \mutsara wekurudyi \zvinyorwa{ -[NH-(CH₂)₆-NH-CO-(CH₂)₄-CO]- }_n + ₂}_n + ₂\chinyorwa
Chinhu chinotevera imvura (H₂O).
Mimwe Mibvunzo yePolymerization
Mubvunzo 3:
Polyethylene terephthalate (PET) inoshandiswa mukugadzira mabhodhoro epurasitiki nemachira. Mamonomer anogadzira PET ndee ethylene glycol (\( \text{HOCH₂CH₂OH} \)) uye terephthalic acid (\( \text{HOOC-C₆H₄-COOH} \)). Tsanangura maitiro ekuumbwa kwePET uye verenga huwandu hwezvakagadzirwa kana tikatanga nemamoles mashanu emonomer yega yega.
Kukurukurirana:
Maitiro ekugadzirisa polymerization ekuumbwa kwePET ndeaya:
\[ n \text{(HOCH₂CH₂OH)} + n \text{(HOOC-C₆H₄-COOH)} \rightarrow \text{ -[OOC-C₆H₄-COO-CH₂CH₂O]- }_n + 2n \text{H₂O} \]
Apo \( n \) iri nhamba yemamoles emonomer. Kana tikatanga nemamoles mashanu eethylene glycol uye mamoles mashanu eterephthalic acid, zvino zvibereko zvinotevera 5 × 2 = 10 mamoles eH₂O.
Zvinhu zveKinematic muPolymerization
Mukuita kwepolymerization, reaction kinetics inokosha. Kuwanda kwepolymerization kunogona kukanganiswa nezvinhu zvakasiyana-siyana zvakaita sekupisa, kumanikidzwa, uye huwandu hwemonomer.
Mubvunzo 4:
Kana chiyero chekupomera kwemhinduro chikanzi \( k [M]^x \), apo k iri chiyero chisingachinji, [M] iri chiyero chemonomer, uye x iri kurongeka kwemhinduro maererano nemonomer, tsanangura kuti shanduko muhuwandu hwemonomer ichakanganisa sei chiyero chemhinduro kana x = 2.
Kukurukurirana:
Kana x iri 2, zvinoreva kuti reaction rate i \( k [M]^2 \). Izvi zvinoreva kuti reaction rate inoenderana zvakananga ne square ye monomer concentration. Kana monomer concentration yakapetwa kaviri, reaction rate ichawedzera kana (2² = 4).
Kugadziriswa kweRedox
Imwe mhando yemaitiro e polymerization ndeye redox polymerization. Izvi zvinosanganisira maitiro e redox pakati pezvinhu zviviri zvinotanga polymerization.
Mubvunzo 5:
Polymer inoumbwa kuburikidza ne redox reaction pakati pe benzoyl peroxide ne styrene. Nyora initiation reaction inoitika.
Kukurukurirana:
Maitiro ekutanga pakati pebenzoyl peroxide nestyrene anogadzira ma free radicals anotanga polymerization. Maitiro acho ndeekuti:
\[ \text{(C₆H₅CO)₂O₂} \rightarrow 2 \text{C₆H₅COO·} \]
Iyo benzoyloxyl radical (\( \text{C₆H₅COO·} \)) inobva yaita styrene, zvichitanga chain reaction yepolymerization.
\[ \text{C₆H₅COO· + CH₂=CHC₆H₅} \rightarrow \text{C₆H₅COOCH₂-CH·C₆H₅} \]
Maitiro aya anoenderera mberi kusvika styrene yasara musystem yaita mhedzisiro yepolystyrene.
Mhedziso
Kunzwisisa mashandiro anoita polymerization uye mashandiro ari shure kwayo kwakakosha kune chero munhu anoshanda mukemistri kana sainzi yezvinhu. Nemienzaniso yakurukurwa pamusoro apa, vaverengi vanotarisirwa kunzwisisa maitiro ekutanga ekuwedzera uye condensation polymerization, pamwe nezvimwe zvinhu zvepamusoro zvakaita se reaction kinetics uye redox polymerization. Nehwaro hwakasimba, tinogona kunzwisisa zviri nani basa rinokosha remapolymers muzvikamu zvakasiyana-siyana zvehupenyu hwemazuva ano.
