Lipotso tsa Mehlala le Puisano ea Tlhaloso le Sebopeho sa Li-polymer
Li-polymer ke metsoako e meholo e entsoeng ka li-unit tse pheta-phetoang tse tsejoang e le li-monomers. K'hemistri, li-polymer li bapala karolo ea bohlokoa lits'ebetsong tse fapaneng, ho tloha indastering ea polasetiki le ea masela ho ea ho biomedicine. Sehlooho sena se tla tšohla tlhaloso ea li-polymer le sebopeho sa tsona, hammoho le ho fana ka mehlala e 'maloa ea mathata le litharollo ho tebisa kutloisiso ea rona ea mohopolo ona.
Ho Utloisisa Li-polymer
Lentsoe polymer le tsoa mantsoeng "poly," a bolelang tse ngata, le "mer," a bolelang yuniti kapa karolo. Kahoo, ka ho toba, polymer ke molek'hule e kholo e entsoeng ka li-unit tse ngata tse nyane tse bitsoang li-monomers. Li-monomers tsena li kopana ka liketso tsa polymerization ho theha meaho e melelele ea ketane.
Mehlala ea Li-polymer tsa Tlhaho le tsa Maiketsetso:
1. Li-polymer tsa tlhaho:
– Cellulose: E entsoe ka li-monomers tsa glucose maboteng a sele ea limela.
– Protheine: E entsoe ka li-amino acid e le li-monomers.
– Rabara ea tlhaho: E entsoe ka polymer ea isoprene.
2. Li-polymer tsa maiketsetso:
– Polyethylene (PE): E sebelisoa ho etsa mekotla ea polasetiki.
– Polypropylene (PP): E sebelisoa ka har'a lijana tse fapaneng tsa polasetiki le linthong tsa lapeng.
– Polyvinyl chloride (PVC): Thepa bakeng sa liphaephe le lisebelisoa tsa bongaka.
Sebopeho sa Polymer
Ka sebopeho, li-polymer li ka aroloa ka mefuta e 'maloa ho latela sebopeho sa tsona le tokisetso ea ketane. Tse latelang ke mefuta ea libopeho tsa polymer:
1. Sebopeho sa Mothati:
– Li-polymer tse nang le sebopeho se otlolohileng li na le liketane tse telele, tse otlolohileng tsa li-monomer tse hokahaneng. Mehlala e kenyelletsa polyethylene le polystyrene.
2. Sebopeho sa Lekala:
– Li-polymer tse nang le makala li na le ketane e kholo e nang le makala a makhutšoane a tsoang ketane e kholo. Mohlala ke polypropylene e nang le makala.
3. Sebopeho sa Marangrang (A hokahantsoe):
– Li-polymer tsena li na le liketane tse hokahaneng ho etsa marang-rang a mahlakore a mararo. Mehlala e kenyelletsa resin ea epoxy le bakelite.
4. Sebopeho sa Copolymer ea Block:
– E entsoe ka mefuta e 'meli kapa ho feta ea li-monomer tse hlophisitsoeng ka mokhoa o hlophisehileng 'me li etsa liboloko tse itseng ho latela ketane ea polymer. Mohlala ke SBS (styrene-butadiene-styrene).
Lipotso tsa Mehlala le Puisano
Ho utloisisa hamolemo moelelo le sebopeho sa li-polymer, mona ke mehlala ea lipotso le lipuisano tsa tsona.
Potso ea 1:
Potso: Bolela liphapang tse tharo tse kholo pakeng tsa li-polymer tsa thermoplastic le thermoset!
Puisano:
– Thermoplastic:
– E ka qhibiliha ha e futhumatsoa mme ea thatafala ha e pholisitsoe, ts'ebetso ena e ka phetoa ka makhetlo a mangata.
– Sebopeho sa limolek'hule se mola kapa se na le makala a manyane.
– Mehlala: Polyethylene (PE), Polypropylene (PP).
– Thermoset:
– Ho feta liphetohong tse ke keng tsa fetoloa tsa lik'hemik'hale ha li futhumatsoa, ho futhumatsoa ha pele ho etsa hore li tiee, empa ka mor'a moo li ke ke tsa qhibilihisoa hape.
– E na le sebopeho sa marangrang se sa fetoheng sa mahlakore a mararo.
– Mehlala: Resin ea epoxy, bakelite.
Potso ea 2:
Potso: Mokhoa oa ho fumana boima ba limolek'hule (Mn) le boima ba limolek'hule (Mw) tsa polymer joang?
Puisano:
– Palo Boima bo Tloaelehileng ba Limolek'hule (Mn):
– Mn = Σ(Ni Mi) / ΣNi
– Moo Ni e leng palo ea limolek'hule tse nang le boima ba limolek'hule Mi.
– Boima Boima bo tloaelehileng ba limolek'hule (Mw):
– Mw = Σ(Ni Mi^2) / Σ(Ni Mi)
– Mw e fa limolek'hule tse nang le boima bo phahameng ba limolek'hule 'me ka kakaretso li feta Mn boima bo boholo.
Potso ea 3:
Potso: Fumana mofuta oa polymer ho tsoa polelong e latelang: "Polima ena e na le sebopeho sa motheo se nang le li-unit tse pheta-phetoang tsa ethylene 'me e na le thepa e tenyetsehang haholoanyane."
Puisano:
– Ho latela polelo ea hore polymer e na le li-unit tse pheta-phetoang tsa ethylene 'me e na le thepa e tenyetsehang, polymer mohlomong ke Polyethylene (PE).
Potso ea 4:
Potso: Hlalosa mekhoa ea ho eketsa polymerization le polymerization ea condensation ka ho fana ka mehlala bakeng sa e 'ngoe le e 'ngoe.
Puisano:
– Ho eketsa polymerization:
– Ts'ebetso eo ho yona di-monomer tse nang le dibonto tse pedi (mohlala, di-alkenes) di kopanang ntle le ho thehwa ha dihlahiswa tse setseng.
– Mohlala: Polyethylene e tsoang ho ethylene.
– n(C2H4) → [-CH2-CH2-]n
– Ho kopanya le ho kopanya:
– Ts'ebetso eo ho yona di-monomer tse pedi kapa ho feta tse nang le dihlopha tse pedi tse fapaneng tsa tshebetso di arabelang, di etsa polymer mme di hlahisa dihlahiswa tse ding tse kang metsi kapa methanol.
– Mohlala: Nylon-6,6 e tswang ho hexamethylenediamine le adipic acid.
– H2N-(CH2)6-NH2 + HOOC-(CH2)4-COOH → [-NH-(CH2)6-NH-CO-(CH2)4-CO-]n + 2nH2O
Potso ea 5:
Potso: Ho boleloa'ng ka regiospecificity ho polymerization mme e ama sebopeho sa polymer joang?
Puisano:
– Ho ikhetha ha sebaka:
– Regiospecificity e bolela ho latela maemo ao li-monomer li kopanang ka ona ka har'a ketane, e leng se etsang qeto ea moralo oa litlamo tsa lik'hemik'hale.
– Li-polymer li ka ba le meaho ea isotactic (li-substituent tsohle ka lehlakoreng le leng la ketane), syndiotactic (li-substituent lia fapanyetsana sebakeng), kapa atactic (li-substituent li ajoa ka mokhoa o sa reroang).
– Mohlala: Polypropylene e ka etsoa e le isotactic PP, syndiotactic PP, kapa atactic PP e amang thepa ea eona ea 'mele, joalo ka kristale le ntlha ea ho qhibiliha.
Qetello
Li-polymer li na le mefuta e mengata ea libopeho le thepa, ho latela mofuta oa monomer le kamoo li hlophisitsoeng kateng ketane ea polymer. Ho utloisisa sebopeho le sebopeho sa li-polymer, hammoho le kamoo li entsoeng kateng, ke senotlolo sa ts'ebeliso ea tsona indastering le theknolojing. Boikoetliso le lipuisano tse fanoeng le tsona li thusa ho matlafatsa likhopolo tsa bohlokoa tsa motheo k'hemistri ea polymer. Ka kutloisiso e ntle, re ka sebelisa li-polymer lits'ebetsong tse fapaneng tse ncha nakong e tlang.
