Tetrafluoroethylene e ile ea lokisoa ka lekhetlo la pele ka 1933. Mokhoa oa hona joale oa khoebo o thehiloe ho fluorspar, sulfuric acid le chloroform.
Mokhoa oa Motheo oa Tlhahiso ea PTFE Polymer:
Tlhahiso ea PTFE Polymer/ Resin ha e le hantle e etsoa ka mekhahlelo e 'meli.Ntlha ea pele, TFE Monomer e atisa ho etsoa ke motsoako oa Calcium Fluoride (Fluorospar), Sulfuric Acid & Chloroform & hamorao polymerisation ea TFE e etsoa ka maemo a laoloang ka hloko ho theha PTFE.Ka lebaka la boteng ba li-bond tse tsitsitseng le tse matla tsa CF, molek'hule ea PTFE e na le lik'hemik'hale tse ikhethang, tse hanyetsanang le mocheso o phahameng le litšobotsi tse tsotehang tsa ho kenya motlakase;ho phaella ho thepa e babatsehang ea likhohlano.
Ho hloekisa TFE:
Ho hlokahala monoma e hloekileng bakeng sa polymerization.Haeba litšila li le teng li tla ama sehlahisoa sa ho qetela.Khase e qala ka ho hlatsuoa ho tlosa hydrochloric acid, ebe e tšeloa ho arola litšila tse ling.
Polymerization ea TFE:
Tetrafluoroethylene e hloekileng e sa thibeleng e ka polima ka pefo, esita le ka mocheso o ka tlase ho mocheso oa kamore.Setsi se silafalitsoeng ka silevera, se tlatsitsoeng ka tharollo e nang le likarolo tse 0.2 tsa ammonium sulphate, likarolo tse 1.5 tsa borax le likarolo tse 100 tsa metsi, le pH ea 9.2.Reactor e ne e koetsoe;evacuated 'me likarolo tse 30 tsa monoma li ile tsa lumelloa ho kena. The reactor e ile ea sisinyeha ka hora e le' ngoe ka 80 ° C 'me ka mor'a hore pholile e fane ka 86% ea lihlahisoa tsa polymer.PTFE e etsoa khoebong ka mekhoa e' meli e meholo, e lebisang ho seo ho thoeng ke 'granular'. polymer 'me ea bobeli e lebisang ho hasane ha polymer ea boholo bo botle haholo ba likaroloana le boima bo tlaase ba limolek'hule.Mokhoa o mong oa ho hlahisa oa ho qetela o ne o kenyelletsa tšebeliso ea motsoako oa 0.1% oa metsi a disuccinic peroxide.Liphetoho li etsoa ka mocheso ho fihlela ho 90 ° C.
Mekhoa e meng:
Ho bola ha TFE tlas'a tšusumetso ea arc ea motlakase.Polymerization e etsoang ka mokhoa oa emulsion ho sebelisa li-initiators tsa peroxide mohlala H2O2 (Hydrogen peroxide) le ferrous sulphate.Maemong a mang, oksijene e sebelisoa e le mothati.
Sebopeho le Lintho tsa PTFE:
The chemical structure of PTFE is linear polymer of C– F2 – C– F2 without any branch & the outstanding properties of PTFE are associated strong & stable Carbon – Fluorine bond.
Polytetrafluoroethylene ke polymer e nang le mela e se nang makala a bohlokoa.Athe molek'hule ea polyethylene e ka sebopeho sa planar zigzag sebakeng sa kristale sena ha se khonehe ka PTFE ka lebaka la liathomo tsa fluorine tse kholo ho feta tsa hydrogen.Ka lebaka leo, molek'hule e nka lesela le sothehileng, 'me liathomo tsa fluorine li paka ka thata ka har'a spiral ho potoloha masapo a carbon-carbon.Phetoho e felletseng ea spiral e tla kenyelletsa liathomo tse fetang 26 tsa khabone ka tlase ho 19°C le 30°C kaholimo ho eona ho na le sebaka sa phetoho se kenyeletsang phetoho ea molumo oa 1% mochesong ona.The compact interlocking ea liathomo tsa fluorine lebisa molek'hule ea ho satalla ho hoholo 'me ke tšobotsi ena e lebisang sebakeng se phahameng sa ho qhibiliha ha kristale le botsitso ba sebopeho sa mocheso oa polymer.
The intermolecular khahloa pakeng tsa PTFE limolek'hule e nyenyane haholo, computed solubility parameter ke 12.6 (MJ/m3) 1/2Polymer ka bongata ha e na ka tsela eo ho na le phahameng rigidity le tensile matla ao hangata a amanang le polymers le phahameng softening ntlha.Bond ea carbon-fluorine e tsitsitse haholo.Ho feta moo, moo liathomo tse peli tsa fluorine li khomaretsoeng ho athomo e le 'ngoe ea carbon ho na le phokotso ea sebaka sa bonto ea C-F ho tloha ho 1.42 A ho ea ho 1.35 A. Ka lebaka leo matla a bond a ka ba holimo ho 504 kJ / mole.Kaha tlamo e 'ngoe feela e teng ke tlamo e tsitsitseng ea C-C, PTFE e na le botsitso bo phahameng haholo ba mocheso, esita le ha e futhumetse ka holim'a ntlha ea eona ea ho qhibiliha ea crystalline ea 327 ° C.Ka lebaka la khanya ea eona e phahameng le ho se khone ho sebelisana ka ho khetheha, ha ho na li-solvents mocheso oa kamore.Lithempereichara tse atamelang moo ho qhibilihang lino tse ling tse nang le fluorinated tse kang per-fluorinated parafine li tla qhibiliha polima.
Thepa ea PTFE e itšetlehile ka mofuta oa polymer le mokhoa oa ho sebetsa.Polymer e ka fapana ka boholo ba likaroloana le / kapa boima ba molek'hule.Boholo ba karoloana bo tla ama boemo ba ts'ebetso le bongata ba voids sehlahisoa se feliloeng ha boima ba molek'hule bo tla ama kristale mme ka hona thepa e mengata ea 'mele.Mekhoa ea ho sebetsana le eona e tla ama kristale le lintho tse se nang letho.
Boima ba boima ba limolek'hule tsa li-polymers tsa khoebo li bonahala li le holimo haholo 'me li ka har'a 400000 ho 9000000. ICI e tlaleha hore thepa ea bona e na le boima ba molek'hule ka har'a 500000 ho ea ho 5000000 le peresente ea crystallinity e kholo ho feta 94 ~ ha e etsoa.Likarolo tse entsoeng ka maiketsetso ha li na kristale e nyane.Tekanyo ea crystallinity ea sehlahisoa se phethiloeng e tla itšetleha ka sekhahla sa ho pholile ho tloha mocheso oa ho sebetsa.Ho pholile butle ho tla lebisa ho crystallinity e phahameng ka ho pholisa ka potlako ho fana ka phello e fapaneng.Lisebelisoa tse tlase tsa boima ba limolek'hule le tsona li tla ba kristale haholoanyane.
Ho hlokometsoe hore polymer ea ho hasana, e nang le boholo bo botle ba likaroloana le boima bo tlaase ba limolek'hule, e fana ka lihlahisoa tse nang le khanyetso e matla haholo ea ho hanyetsa ho fetoha le matla a phahameng ka ho hlaka.Lintlafatso tsena li bonahala li hlaha ka ho theha meaho e kang fiber ka bongata ba polymer nakong ea ts'ebetso.
Nako ea poso: Jan-04-2019