Mmeghachi omume Polymerization
Pendahuluan
Polymers bụ ngwakọta kemịkalụ nke mejupụtara nnukwu molekul ogologo ogologo nke mejupụtara nkeji ugboro ugboro a na-akpọ monomers. Polymerization bụ usoro kemịkalụ nke monomers ndị a ji ejikọta ọnụ iji mepụta polymers. Usoro a dị oke mkpa n'ụlọ ọrụ kemịkalụ ma na-enye aka na mmepụta nke ọtụtụ ihe bara uru, gụnyere plastik, roba, na eriri sịntetik.
Isiokwu a na-achọ ịkọwa usoro, ụdị, na ojiji nke mmeghachi omume polymerization. Usoro polymerization nwere ike ime site na usoro dị iche iche, yana isi edemede abụọ: polymerization mgbakwunye na polymerization condensation.
Ụdị Polymerization
Mgbakwunye Polymerization
Mmepụta polymerization nke mgbakwunye bụ usoro ebe monomers nwere njikọ abụọ ma ọ bụ atọ na-emeghachi omume iji mepụta polymer na-enweghị mmepụta ihe ndị ọzọ. A na-akpọ polymers ndị a na-emepụta site na ụdị polymerization a na-agbakwụnye polymers.
Langkah-langkah:
1. Mmalite: Mmeghachi omume ahụ na-amalite mgbe onye na-ebido mmepụta ihe mepụtara radicals free, ions, ma ọ bụ ihe mkpali nke nwere ike imebi njikọ abụọ na monomers.
2. Mgbasa: Radicals ma ọ bụ ion ndị a kpụrụ na-emeghachi omume na monomers, na-emepụta nsọtụ ọhụrụ na-arụ ọrụ nke nwere ike imeghachi omume na monomers ndị ọzọ.
3. Nkwụsị: Mmeghachi omume ahụ na-akwụsị mgbe radicals abụọ nwere onwe ha zutere ma mepụta njikọ covalent, ma ọ bụ mgbe usoro ọzọ kwụsịrị mgbasa.
Ebe:
– Poly(ethylene): Ethylene monomer (C2H4) na-emeghachi omume site na usoro nke free radicals iji mepụta poly(ethylene).
– Poly(vinyl chloride) (PVC): A na-ejikọta ihe ndị na-emepụta vinyl chloride (C2H3Cl) site na mmalite, mgbasa, na njedebe.
Ntụpọ Polymerization
Mmepụta polima nke condensation gụnyere monomers nwere ma ọ dịkarịa ala otu ọrụ abụọ na-arụ ọrụ ma na-emepụta polima nwere mmepụta nke ihe sitere na ngwaahịa, dị ka mmiri ma ọ bụ methanol.
Langkah-langkah:
1. Mmalite: Monomers ndị nwere otu ọrụ na-emegharị ahụ na-emeghachi omume n'etiti onwe ha.
2. Nhazi: Nhazi nke njikọ dị n'etiti monomers, yana mwepụta nke molekul ọkụ, dịka H2O ma ọ bụ HCl.
3. Uto Agbụ: Usoro a na-aga n'ihu ruo mgbe monomers ahụ gwụchara ma ọ bụ ọnọdụ mmeghachi omume adịghịzi mma.
Ebe:
– Naịlọn-6,6: Emere ya site na mmeghachi omume dị n'etiti hexamethylenediamine na adipic acid, nke na-emepụta mmiri dị ka ihe na-esote.
– Polyester: E mepụtara ya site na mmeghachi omume dị n'etiti terephthalic acid na ethylene glycol, site na mmiri dị ka ihe na-esote.
Usoro Mmezi Polymerization
Mmezi Polymerization Radical Free
Mmepụta polymerization nke nwere oke radikal bụ otu n'ime usoro mgbakwunye polymerization kachasị ewu ewu. Usoro a na-amalite site na ịmepụta radicals nwere oke radikal na-arụ ọrụ nke ọma, nke na-abụkarị site na okpomọkụ ma ọ bụ fotoinitiation.
1. Mmalite: A na-ekewa mkpụrụ ndụ ihe mmalite dịka benzoyl peroxide ma ọ bụ azobisisobutyronitrile (AIBN) iji mepụta ihe ndị na-akpata ihe mgbu.
\[ \text{(Rịba ama, AIBN) → 2 \cdot (Radical, )} \]
2. Mgbasa: Radicals efu na-emeghachi omume na monomers iji mepụta radicals monomer gbasaara:
\[ \text{(Radical + Monomer) → (R-Polymer)} \]
3. Nkwụsị: Radicals abụọ nwere onwe ha na-ejikọta ọnụ iji mepụta molekul na-abụghị nke radicals ma kwụsị mmeghachi omume agbụ ahụ:
\[ \text{(R + R) → Mmepụta Ihe Na-abụghị nke Radical} \]
Ionic Polymerization
Mmepụta polymerization a gụnyere imepụta ion (cations ma ọ bụ anions) dị ka ụdị mmeghachi omume. Enwere ike kewaa polymerization Ionic n'ime ụdị isi abụọ, ya bụ:
– Njide Cationic Polymerization: Na-agụnye ụdị cationic dị ka ihe mmalite. A na-ejikarị ya na monomers nwere otu ndị na-enye electron dịka isobutylene.
– Mmepụta ihe nke Anionic: Ọ na-agụnye ion (anions) ndị na-anaghị anabata ihe nke ọma dị ka ndị na-amalite ihe. A na-eji ya na monomers ndị nwere otu ndị na-anabata elektrọn dịka styrene.
Nhazi Polymerization
Ụdị polymerization a na-eji ihe ndị na-akpali mgbanwe ígwè dị mgbagwoju anya, ihe atụ bụ Ziegler-Natta polymerization nke e ji eme polyethylene na polypropylene stereo-regular.
1. Ihe ndị na-akpali akpali: A na-eji ígwè mgbanwe dịka titanium chloride na ngwakọta organometallic dịka aluminum triethyl (AlEt3).
2. Mmeghachi omume: Monomers na-ejikọta ọnụ n'ọnọdụ ọrụ nke ihe mejupụtara ígwè ahụ.
Ngwa Polymerization
Ụlọ ọrụ plastik
Plastik bụ ngwaahịa polima kacha mara amara ma na-ejikarị eme ihe. A na-eme ha site na usoro polymerization mgbakwunye na condensation. Ihe atụ nke ngwaahịa polymerization plastik a na-ahụkarị gụnyere polyethylene, polypropylene, PVC, na PET (polyethylene terephthalate). A na-eji plastik eme ihe n'imepụta nkwakọ ngwaahịa, ihe egwuregwu, paịpụ, na ọtụtụ ngwaahịa ndị ọzọ eji eme ihe.
Ihe Eriri
Eriri sịntetik dịka naịlọn na polyester bụ ihe si na polymerization condensation pụta. A na-eji ha eme ihe n'ịmepụta ákwà, uwe, na ihe ndị e ji eme ụlọ dịka kapeeti na eriri. A na-ahọrọkarị eriri maka ike ha, iguzogide abrasion, na ike ha.
Rọba sịntetik
Rubber sịntetik, dịka polybutadiene na styrene-butadiene (SBR), bụ ngwaahịa sitere na polymerization agbakwunyere nke monomers nwere diene. A na-eji rọba ndị a eme ihe n'ịmepụta taya ụgbọala, ihe mkpuchi, na ọtụtụ ngwa ụlọ ọrụ n'ihi na ha na-eguzogide nchacha na mgbanwe.
Epoxy Resins na Thermosetting Polymers
Epoxy resins bụ ihe si na polima condensation nke na-eme n'ọnọdụ okpomọkụ ụlọ ma ọ bụ na okpomọkụ. A na-eji ha eme ihe na gluu, agba, na ihe ndị mejupụtara ya nke chọrọ iguzogide okpomọkụ na kemịkalụ. A pụghị ịgbaze polima thermosetting ndị a mgbe ha gwọrọ, n'adịghị ka polima thermoplastic.
Biomedis
Polymers eji eme ihe na biomedical gụnyere polylactide (PLA) na poly(tetrahydrofurane) (PTHF), nke a na-eji emepụta ihe ndị a na-akpọ bioresorbable implant. Emebere polymers ndị a ka ha gbazee n'ahụ, na-ebelata mkpa ọ dị iwepụ ịwa ahụ nke abụọ.
Ihe Electroactive
Polymers electroactive bụ polima ndị na-agbanwe ọdịdị ha n'okpuru mmetụta nke ubi eletriki, nke a na-ejikarị eme ihe na ihe mmetụta. Ihe atụ gụnyere poly(3,4-ethylenedioxythiophene) (PEDOT), nke a na-eji na ngwaọrụ eletrọniki dịka ihe mmetụ aka.
Mmechi
Mmeghachi omume nke polymerization bụ usoro kemịkalụ dị mkpa n'ụlọ ọrụ kemịkalụ nke oge a, na-emeghe ụzọ maka ọtụtụ ngwaahịa na ngwa ndị na-agbanwe ndụ anyị kwa ụbọchị. Site n'ịghọta usoro na ụdị polymerization, yana ngwa ha, anyị nwere ike ịmepụta ihe ọhụrụ nwere ihe ndị ka mma maka mkpa n'ọdịnihu. Mgbakwunye polymerization na condensation polymerization nke ọ bụla na-arụ ọrụ pụrụ iche na nhazi nke ihe ndị a, sayensị na-agakwa n'ihu ịchọpụta ụzọ ọhụrụ iji melite usoro ndị a ma chọta ngwa ọhụrụ maka polymers.
