I-Polytetrafluoroethylene yi-fluoropolymer eyenziwe ye-tetrafluoroethylene enezicelo ezininzi.Elona gama lebhrendi laziwa kakhulu leefomyula ezisekwe kwi-PTFE yipolymer yiChemours.Indawo yokunyibilikisa: 620.3°F (326.8°C);Ifomula: (C2F4)n;Uxinzelelo: 2.2 g/cm³;I-ID ye-IUPAC: ipoly(1,1,2,2-tetrafluoroethylene).
I-PTFE iveliswa nge-free-radical polymerization mechanism kumajelo eendaba anamanzi ngokongezwa kwepolymerization ye-TFE kwinkqubo yebhetshi.Umqalisi wepolymerization udla ngokuba yiperoksayidi enyibilikayo emanzini efana neammonium persulfate okanye idisuccinic peroxide.I-redox catalyst isetyenziselwa ubushushu obuphantsi bepolymerization.I-PTFE iveliswa ngokunqunyanyiswa (okanye i-slurry) i-polymerization ngaphandle kwe-surfactant ukufumana i-resin ze-granular okanye nge-perfluorinated surfactant (emulsion polymerization) njenge-ammonium perfluorooctanoate ukuvelisa umgubo ococekileyo kunye neemveliso ze-dispersion.Ukushisa kwe-polymerization kunye noxinzelelo ngokuqhelekileyo luvela kwi-0 ukuya kwi-100 C kunye ne-0.7 ukuya kwi-3.5 MPa.
IGranular PTFE iveliswa ngepolymerizing TFE yodwa okanye ngokusebenzisa amanani trace of comonomers.Isiqalisi seperoxide, i-surfactant encinci okanye ingabikho, kunye nezinye izongezo zinokubakho kwi-aqueous polymerization medium eshukunyiswa ngamandla kwaye ngamanye amaxesha ihlaselwe sisinyibiliko sealkaline.Uninzi lwepolymer lwenziwe kwisigaba segesi ngokubunjwa kweentambo kunye neengqungquthela ezingaqhelekanga.Iinqununu zihanjiswa kubukhulu obuhlukeneyo, kuxhomekeke kwiimpawu ze powder ezifunwa yinkqubo yokwenziwa.Umzekelo, indawo egudileyo yomphezulu ifuna ubungakanani bamasuntswana amancinci ngelixa ukuhamba kakuhle kuphuculwa ngobungakanani bamasuntswana amakhulu.
Umgubo ococekileyo we-PTFE uveliswa yi-polymerization ye-TFE kwindawo enamanzi phambi komqalisi kunye ne-surfactant.I-polymerization ayilandeli indlela ye-emulsion eqhelekileyo kodwa eminye yemigaqo, esebenzayo.Ukuzinza kwe-dispersion ngexesha le-polymerization, ukuphepha ukudibanisa kwangaphambi kwexesha, kulungelelaniswa ngokuchasene nesidingo sokuphula i-emulsion yokubuyisela i-PTFE.Ukuchetywa kwesantya esisezantsi kuyagcinwa ngexesha lepolymerization kusetyenziswa amanqanaba e-surfactant angaphantsi koxinzelelo olubalulekileyo lwemicelle.Izinga le-polymerization kunye ne-particle shape kunye nobukhulu buchaphazeleka ngokuxinwa kwe-surfactant.Ubuninzi beengqungquthela ziveliswa kwindawo yokuqala ye-polymerization kwaye ikhula njengoko umjikelezo uqhubeka.Ubunzima be-molecular kunye nokubunjwa ngaphakathi kweqhekeza kunokulawulwa ngokusebenzisa izithako kunye neemeko ze-polymerization.
Inkqubo efanayo ye-polymerization yenza i-aqueous dispersions ye-PTFE njengomgubo ocolekileyo.Ukusasazwa kugxininiswe kwaye kuzinziswe kusetyenziswa iindidi ze-ionic kunye ne-nonionic surfactants.Iindlela ezininzi zoxinaniso ziye zaxelwa kubandakanywa i-electrodecantation, i-evaporation, kunye ne-thermal concentration.Izongezo zemichiza ukuzifanisa nenkqubo yokwenziwa okanye inxalenye yeemfuno zepropathi inokuguqula ukusasazwa kokugqibela kwePTFE.
Iikhompawundi ezizaliswe ziveliswa kuzo zontathu iifom ze-PTFE kusetyenziswa izizalisi ezifana nefiber yeglasi, igraphite, umgubo wesinyithi, i-carbon fiber, kunye nabanye.
Ixesha lokuthumela: Sep-24-2018