Tali atu o le Polymerization
Pendahuluan
O polymers o ni vailaʻau faʻapitoa e aofia ai ni molelaʻau tetele ma uumi e fausia i ni iunite faifai pea e taʻua o monomers. O le polymerization o le faiga faʻakemikolo lea e tuʻufaʻatasia ai nei monomers e fausia ai ni polymers. E taua tele lenei faiga i le alamanuia o vailaʻau ma e fesoasoani i le fausiaina o le tele o mea taua, e aofia ai palasitika, paʻu, ma alava faʻapitoa.
O lenei tusiga e faʻamoemoe e faʻamatalaina auala, ituaiga, ma faʻaoga o tali o le polymerization. E mafai ona tupu faiga o le polymerization e ala i auala eseese, e lua vaega autu: addition polymerization ma condensation polymerization.
Ituaiga o le Polymerization
Fa'aopoopoga Polymerization
O le fa'aopoopoga o le polymerization o se faiga lea e tali atu ai monomers e iai ni fusiua faalua pe tolu e fausia ai se polymer e aunoa ma le gaosia o ni oloa e fesoasoani i ai. O polymers e gaosia e lenei ituaiga o polymerization e ta'ua o le addition polymers.
Laasaga-laasaga:
1. Fa'aosofiaga: E amata le tali atu pe a gaosia e se fa'aosofiaga ni radicals saoloto, ions, po'o ni catalysts e mafai ona motusia ai fusi fa'alua i monomers.
2. Fa'asalalauina: O radicals saoloto po'o ions na fausia e tali atu i monomers, ma fausia ai ni pito fou e mafai ona tali atu i isi monomers.
3. Fa'amutaina: E muta le tali atu pe a feiloa'i ni radicals saoloto se lua ma fausia ai se fusi fa'atasi, pe a taofia e se isi auala le fa'asalalauina.
Faataitaiga:
– Poly(ethylene): E tali atu le ethylene monomer (C2H4) e ala i se filifili o radicals saoloto e fausia ai le poly(ethylene).
– Poly(vinyl chloride) (PVC): O monomers vinyl chloride (C2H3Cl) e fa'apipi'i e ala i le amataina, fa'asalalauina, ma le fa'amutaina.
Fa'aputuga Fa'aputuga
O le polymerization o le condensation e aofia ai monomers e iai ni vaega fa'atino e lua pe sili atu ma fausia ai se polymer ma le i'uga o se oloa e maua mai ai, e pei o le vai po'o le methanol.
Laasaga-laasaga:
1. Amataga: O Monomers e iai ni vaega galue tali vave e tali atu le tasi ma le isi.
2. Fausiaina: Fausiaina o sootaga i le va o monomers, faatasi ai ma le tatalaina o mole mole mama, e pei o le H2O po o le HCl.
3. Tuputupu Aʻe o le Filifiliga: O lenei faagasologa e faaauau pea seia oo ina uma monomers pe ua le toe lelei tulaga o le tali atu.
Faataitaiga:
– Nylon-6,6: E maua mai i le tali atu i le va o le hexamethylenediamine ma le adipic acid, lea e maua mai ai le vai o se oloa faaopoopo.
– Polyester: E fausia mai le tali atu i le va o le terephthalic acid ma le ethylene glycol, faatasi ai ma le vai o se oloa faaopoopo.
Faiga Fa'apolymerization
Polymerization Radical Sa'oloto
O le polymerization o le free radical o se tasi lea o faiga masani o le polymerization faaopoopo. O lenei faagasologa e amata i le fausiaina o free radicals e matua tali vave, e masani lava e ala i le thermal po o le photoinitiation.
1. Fa'aosofiaga: O mole mole mole e pei o le benzoyl peroxide po'o le azobisisobutyronitrile (AIBN) e vaevaeina e maua ai ni free radicals.
\[ \text{(Fa'amatalaga, AIBN) → 2 \cdot (Radical, )} \]
2. Fa'asalalauina: E tali atu radicals saoloto ma monomers e fausia ai ni monomer radicals fa'alauteleina:
\[ \text{(Radical + Monomer) → (R-Polymer )} \]
3. Fa'amutaina: E tu'ufa'atasia ni radicals saoloto se lua e fausia ai se mole mole e le o ni radical ma taofi ai le tali fa'asolosolo:
\[ \text{(R + R ) → Gaosiga e lē Fa'atuputeleina} \]
Fa'apolimerisasiona Ionic
O lenei polymerization e aofia ai le fausiaina o ions (cations poʻo anions) e fai ma reactive species. E mafai foʻi ona vaevaeina le Ionic polymerization i ni ituaiga autu se lua, o lona uiga:
– Cationic Polymerization: E aofia ai se ituaiga cationic e fai ma initiator. E masani ona faʻaaogaina ma monomers e iai vaega e foaʻi mai ai eletise e pei o le isobutylene.
– Anionic Polymerization: E aofia ai ions (anions) e molia leaga e fai ma initiators. E fa'aaogaina i monomers e iai vaega e talia eletise e pei o le styrene.
Fa'apolimerina Fa'amaopoopo
O lenei ituaiga o polymerization e fa'atautaia e ala i fa'aosofiaga o le transition metal complex catalysts, o se fa'ata'ita'iga o le Ziegler-Natta polymerization e fa'aaoga e fai ai le stereo-regular polyethylene ma le polypropylene.
1. Mea Fa'aola: O u'amea fesuia'i e pei o le titanium chloride e fa'aaogaina fa'atasi ma mea fa'a-organometallic e pei o le aluminum triethyl (AlEt3).
2. Tali: E tu'ufa'atasia monomers i le tulaga galue o le u'amea fa'aputu.
Fa'aoga Polymerization
Alamanuia Palasitika
O palasitika o oloa polymer e sili ona lauiloa ma faʻaaogaina lautele. E gaosia e ala i faiga faʻaopoopo ma le faʻaputuga polymerization. O faʻataʻitaʻiga o oloa polymerization palasitika masani e aofia ai le polyethylene, polypropylene, PVC, ma le PET (polyethylene terephthalate). E faʻaaogaina palasitika i le gaosiga o afifiina, meataalo, paipa, ma le tele o isi oloa faʻatau.
Meafaitino Fa'i
O alava fa'apitoa e pei o le nylon ma le polyester o le taunuuga lea o le fa'aputuga o le condensation. E fa'aaogaina i le gaosiga o ie, lavalava, ma mea tau fale e pei o kapeta ma maea. E masani ona filifilia alava ona o lo latou malosi, tete'e atu i le olo, ma le fetuutuuna'i.
Pa'u Fa'apitoa
O pa'u fa'apitoa, e pei o le polibutadiene ma le styrene-butadiene (SBR), o oloa ia o le fa'aopoopoga o le polymerization o monomers o lo'o i ai le diene. O nei pa'u e fa'aaogaina i le gaosiga o pa'u ta'avale, fa'amaufa'ailoga, ma isi fa'aoga fa'apisinisi ona o lo latou tete'e atu i le olo ma le fa'aleagaina.
Resin Epoxy ma Polymers Thermosetting
O resins epoxy o le taunuuga lea o le polymerization o le condensation lea e tupu i le vevela o le potu po'o le fa'avevela. E fa'aaogaina i mea fa'apipi'i, vali, ma mea fa'apipi'i e mana'omia le tete'e atu i le vevela ma vaila'au. O nei polymers thermosetting e le mafai ona toe fa'ama'a'aina pe a uma ona fa'amago, e le pei o polymers thermoplastic.
Biomedis
O polymers e faʻaaogaina i galuega faʻafomaʻi e aofia ai le polylactide (PLA) ma le poly(tetrahydrofurane) (PTHF), ia e faʻaaogaina e fatu ai mea faʻapipiʻi bioresorbable. O nei polymers ua mamanuina ina ia pala i totonu o le tino, ma faʻaitiitia ai le manaʻomia o se taotoga lona lua e aveese ai.
Meafaitino Fa'aeletise
O polymers eletise o polymers ia e suia foliga i lalo o le faatosinaga o se fanua eletise, e masani ona faʻaaogaina i actuators ma sensors. O faʻataʻitaʻiga e aofia ai le poly(3,4-ethylenedioxythiophene) (PEDOT), lea e faʻaaogaina i masini eletise e pei o touchscreens.
I'uga
O tali atu o le polymerization o ni faiga fa'akemikolo taua i le alamanuia fa'akemikolo fa'aonaponei, e saunia ai le ala mo le tele o oloa ma fa'aoga e suia ai o tatou olaga i aso faisoo. I le malamalama i faiga ma ituaiga o le polymerization, fa'apea fo'i ma a latou fa'aoga, e mafai ona tatou atia'e ni mea fou fa'atasi ai ma meatotino fa'aleleia mo mana'oga i le lumana'i. O le addition polymerization ma le condensation polymerization e tofu ma matafaioi tulaga ese i le fausiaina o nei mea, ma o lo'o fa'aauau pea ona alualu i luma le saienisi e su'e ni auala fou e fa'aleleia atili ai nei faiga ma maua ni fa'aoga fou mo polymers.
