Fa'ata'ita'iga o Fesili e Talanoaina ai le Fa'aopoopoga o le Polymerization
O le polymerization o le faagasologa lea e tuufaatasia ai monomers—o ni molela laiti e tutusa o latou fausaga—e fausia ai ni molela tetele e ta'ua o polymers. E lua ituaiga autu o le polymerization: addition polymerization ma le condensation polymerization. O lenei tusiga o le a talanoaina ai se tasi o nei ituaiga, o le addition polymerization, faatasi ai ma se faamamafa i faataitaiga ma talanoaga e tuuina atu ai se malamalamaga loloto o lenei manatu.
Malamalama i le Fa'aopoopoga Polymerization
O le fa'aopoopoga o le polymerization o se faiga lea e tu'ufa'atasia ai monomers e aunoa ma le leiloa o mole mole laiti e pei o le vai po'o le HCl. O monomers e masani ona a'afia i le fa'aopoopoga o le polymerization o alkenes ma alkenes polarized, o lo'o i ai ni fusi fa'alua carbon-carbon (C=C). A tali atu nei monomers, e motusia fusi fa'alua, ma mafai ai e monomers ona tu'ufa'atasia i ni filifili uumi.
O faʻataʻitaʻiga o polymers e gaosia e ala i le faʻaopoopoga o le polymerization e aofia ai le polyethylene (PE), polypropylene (PP), polystyrene (PS), ma le polyvinyl chloride (PVC). O nei polymers uma e taua i le alamanuia ma le olaga i aso faisoo ona o lo latou malosi, mautu, ma le lautele o faʻaoga.
Fa'aopoopoga o le Polymerization Mechanism
E mafai ona vaevaeina le faiga o le polymerization faaopoopo i ni vaega autu se tolu:
1. Amataga: O le la'asaga lea e fausia ai ni radicals saoloto po'o ni ions e amata ai le tali atu.
2. Fa'asalalauina: O le la'asaga lea e fa'aauau ai ona tu'ufa'atasia monomers e fausia ai ni filifili uumi.
3. Fa'amutaina: O le tulaga lea e taofi ai le tali atu ona o le tu'ufa'atasia o filifili o radical saoloto e lua pe ona feiloa'i ai radical saoloto ma se mea e taofia ai.
Mo se faamaninoga, o se talanoaga lea o ni nai faataitaiga o fesili o le polymerization faaopoopo.
Fesili Fa'ata'ita'i ma Talanoaga
Fesili 1: Fa'apolimerina o le Polyethylene
Fesili: Fa'amatala le fa'agasologa o le fa'aopoopoina o le polymerization o le ethylene (C2H4) e fausia ai le polyethylene (PE), fa'aofi ai le fa'atusatusaga o le tali atu e tupu.
Talanoaga:
– Fa'auluuluga:
E mafai ona ausia le amataga e ala i le faʻaaogaina o mea faʻatupu faʻalavelave poʻo ni free radicals. Seʻi tatou faʻapea o loʻo tatou faʻaaogaina ni free radicals. O mea faʻatupu faʻalavelave e pei o le benzoyl peroxide (C14H10O4) e mafai ona faʻasaʻoloto ni free radicals pe a faʻavevela.
\[
C14H10O4 \rightarrow 2C6H5COO^{\cdot}
\]
– Fa'asalalauina:
O nei radicals o le a osofaʻia fusi faalua i le ethylene monomer, ma maua ai ni radicals fou e mafai ona faaauau ona osofaʻia le isi monomer.
\[
R^{\cdot} + CH2=CH2 \rightarrow R-CH2-CH2^{\cdot}
\]
Sosoo ai, o le a faʻaauau pea ona faʻaopoopoina e radicals i le pito o le filifili ia monomers ethylene ina ia umi ai le filifili.
\[
R-CH2-CH2^{\cdot} + nCH2=CH2 \rightarrow R-(CH2-CH2)_n^{\cdot}
\]
– Fa'amutaina:
E mafai ona tupu le faamutaina e ala i le tuufaatasiga o filifili radical e lua po o se tali i le va o se radical ma se inhibitor.
\[
R-(CH2-CH2)_n^{\cdot} + R-(CH2-CH2)_m^{\cdot} \rightarrow R-(CH2-CH2)_{n+m}-R
\]
O le i'uga o le polyethylene (PE), o se polymer e maua mai i le tu'ufa'atasia o le tele o monomers ethylene (\(n\) ethylene).
Fesili 2: Fa'apolimerina o le Polystyrene
Fesili: O se pisinisi vailaʻau e manaʻo e gaosia se polymer mai le monomer styrene (C8H8). Faʻamatala le tali atu o le polymerization e tupu ma tusi le fausaga o le polystyrene.
Talanoaga:
– Fa'auluuluga:
E pei lava o le polyethylene, e manaʻomia ni free radicals e amata ai le tali atu. Seʻi faapea tatou te faʻaaogaina ni peroxide radicals.
\[
ROOR \rightarrow 2RO^{\cdot}
\]
– Fa'asalalauina:
E osofa'ia e free radicals ia styrene monomers e iai ni carbon-carbon double bonds.
\[
RO^{\cdot} + C6H5-CH=CH2 \rightarrow RO-C6H5-CH^{\cdot}-CH3
\]
O le laʻasaga o le faʻasalalauina o le a faʻaauau ai ona osofaʻia e nei vailaʻau faʻasolosolo isi monomers styrene.
\[
RO-C6H5-CH^{\cdot}-CH3 + n(C6H5-CH=CH2) \rightarrow RO-(C6H5-CH-CH2)_n-C6H5-CH^{\cdot}-CH3
\]
– Fa'amutaina:
E tupu le fa'amutaina pe a feiloa'i filifili polymer se lua.
\[
RO-(C6H5-CH-CH2)_n^{\cdot} + RO-(C6H5-CH-CH2)_m^{\cdot} \rightarrow RO-(C6H5-CH-CH2)_{n+m}-RO
\]
O le iʻuga o le fausaga o le polystyrene (PS) o se filifili umi e aofia ai iunite monomer styrene faifai pea.
Fesili 3: Fa'apolimerina o le Polyvinyl Chloride (PVC)
Fesili: Fa'amatala le fa'aopoopoga o le polymerization o le vinyl chloride monomer (C2H3Cl), ma tu'uina atu ni fa'ata'ita'iga o fa'aoga o le polyvinyl chloride (PVC).
Talanoaga:
– Fa'auluuluga:
E pei lava o le faʻataʻitaʻiga muamua, o free radicals e maua mai i peroxides.
\[
ROOR \rightarrow 2R-O^{\cdot}
\]
– Fa'asalalauina:
E osofa'ia e free radicals ia fusi fa'alua i totonu o le vinyl chloride monomers.
\[
RO^{\cdot} + CH2=CHCl \rightarrow RO-CH2-CHCl^{\cdot}
\]
E faʻaauau pea le faʻasalalauina o le faʻatasi ai ma iunite monomer e soʻotaga e faʻalautele ai le filifili.
\[
RO-CH2-CHCl^{\cdot} + nCH2=CHCl \rightarrow RO-(CH2-CHCl)_n^{\cdot}
\]
– Fa'amutaina:
E tupu le fa'amutaina pe a fa'apipi'i fa'atasi filifili autu e lua.
\[
RO-(CH2-CHCl)_n^{\cdot} + RO-(CH2-CHCl)_m^{\cdot} \rightarrow RO-(CH2-CHCl)_{n+m}-RO
\]
O le Polyvinyl chloride (PVC) o se polymer e gaosia ma faʻaaogaina i le tele o faʻaoga e pei o paipa vai, uaea eletise, ma isi oloa palasitika.
I'uga
O le fa'aopoopoga o le polymerization o se faiga taua fa'akemikolo e aofia ai le tu'ufa'atasia o monomers e aunoa ma le fa'asa'olotoina o mole mole laiti. O le malamalama i faiga ma tali atu o le fa'aopoopoga o le polymerization, e pei o mea e va'aia i le polyethylene, polystyrene, ma le PVC, e fesoasoani ia i tatou e a'oa'o ma fa'aoga lenei malamalama i pisinisi ma le olaga i aso faisoo. E ala i nei fa'ata'ita'iga ma talanoaga, e mafai ona tatou maua se malamalamaga loloto i faiga ma oloa e mafua mai i le fa'aopoopoga o le polymerization, fa'apea fo'i ma ona fa'aoga aoga e a'afia ai tekinolosi ma le olaga fa'aonaponei.
