Tsarin samarwa na PTFE

An fara shirya Tetrafluoroethylene a cikin 1933. Haɗin kasuwanci na yanzu yana dogara ne akan fluorspar, sulfuric acid da chloroform.

Asalin Tsarin Samar da PTFE Polymer:

Samfuran PTFE Polymer/Resin ana aiwatar da shi a matakai biyu.Na farko, TFE Monomer gabaɗaya ana kera shi ta hanyar haɗakar Calcium Fluoride (Fluorospar), Sulfuric Acid & Chloroform kuma daga baya polymerisation na TFE ana aiwatar da shi cikin yanayin sarrafawa da kyau don samar da PTFE.Saboda kasancewar barga & ƙarfi CF bonds, PTFE kwayoyin sun mallaki fitattun sinadarai inertness, high zafi juriya & na ban mamaki lantarki rufi halaye;ban da kyawawan kaddarorin juzu'i.

Tsaftace TFE:

Ana buƙatar monomer mai tsabta don yin polymerization.Idan najasa ya kasance zai shafi samfurin ƙarshe.Ana fara goge iskar gas don cire duk wani acid hydrochloric sannan a distilled don raba sauran datti.

Polymerization na TFE:

Tetrafluoroethylene mai tsabta wanda ba a hana shi ba zai iya yin polymerise tare da tashin hankali, har ma a yanayin zafi da farko a ƙasa da zafin jiki.Reactor da aka yi da azurfa, kwata-kwata cike da bayani wanda ya ƙunshi sassa 0.2 ammonium persulphate, sassan borax 1.5 da sassan ruwa 100, kuma tare da pH na 9.2.An rufe reactor;An kwashe kuma an bar sassan 30 na monomer a ciki. An tayar da reactor na sa'a daya a 80 ° C kuma bayan sanyaya ya ba da 86% na polymer. PTFE ana yin kasuwanci ta hanyar manyan matakai guda biyu, wanda ke haifar da abin da ake kira 'granular'. polymer kuma na biyu yana haifar da tarwatsewar polymer na girman girman ƙwanƙwasa da ƙananan nauyin kwayoyin halitta.Hanya ɗaya ta samar da ƙarshen ta haɗa da amfani da maganin disuccinic acid peroxide na 0.1°% mai ruwa.An gudanar da halayen a zazzabi har zuwa 90 ° C.

Wasu hanyoyin:

Rushewar TFE a ƙarƙashin rinjayar baka na lantarki.Polymerisation da aka yi ta hanyar emulsion ta hanyar amfani da peroxide initiators misali H2O2 (Hydrogen peroxide) da ferrous sulphate.A wasu lokuta ana amfani da iskar oxygen a matsayin mai farawa.

Tsarin da Kaddarorin PTFE:

Tsarin sinadarai na PTFE shine polymer madaidaiciya na C-F2 - C- F2 ba tare da wani reshe ba & fitattun kaddarorin PTFE suna da alaƙa da ƙarfi & barga Carbon-Fluorine bond.

Polytetrafluoroethylene polymer polymer ne mai layi wanda ba shi da kowane adadi mai mahimmanci na reshe.Ganin cewa kwayoyin polyethylene yana cikin siffar zigzag na planar a cikin yanki na crystalline wannan ba zai yiwu ba da na PTFE saboda atom ɗin fluorine ya fi na hydrogen girma.A sakamakon haka, kwayoyin suna ɗaukar zigzag karkatacciyar hanya tare da atom ɗin fluorine suna tattarawa sosai a cikin karkace kewayen kwarangwal-carbon.Cikakken juzu'i na karkace zai ƙunshi fiye da 26 carbon atom ɗin ƙasa da 19 ° C da 30 ° C a sama da shi akwai wurin canji wanda ya haɗa da canjin ƙarar 1% a wannan zafin jiki.Ƙaƙƙarfan haɗaɗɗen nau'in atom ɗin fluorine yana haifar da ƙwayar ƙwayar cuta mai ƙarfi kuma wannan fasalin shine ke haifar da babban ma'anar narkewar crystalline da yanayin yanayin zafi na polymer.

Abubuwan jan hankali na intermolecular tsakanin kwayoyin PTFE kadan ne, ma'aunin solubility da aka lissafta shine 12.6 (MJ / m3) 1 / 2 polymer a cikin girma ba ya da ƙarfin ƙarfi da ƙarfi wanda galibi ana danganta shi da polymers tare da babban ma'ana mai laushi.Haɗin carbon-fluorine yana da ƙarfi sosai.Bugu da ari, inda atom ɗin fluorine guda biyu ke haɗe da zarra na carbon guda ɗaya ana samun raguwar nisan haɗin haɗin C-F daga 1.42 A zuwa 1.35 A. Sakamakon ƙarfin haɗin gwiwa na iya kaiwa 504 kJ/mole.Tun da kawai sauran haɗin da ke akwai shine bargawar C-C bond, PTFE yana da kwanciyar hankali mai zafi sosai, koda lokacin zafi sama da wurin narkewar crystalline na 327°C.Saboda girman crystallinitynsa da rashin iya takamaiman mu'amala, babu wasu kaushi a zafin jiki.A yanayin zafi da ke gabatowa wurin narkewa wasu ruwaye masu kyalli irin su kananzir mai-fluorinated zai narke polymer.

Kaddarorin PTFE sun dogara da nau'in polymer da hanyar sarrafawa.polymer na iya bambanta da girman barbashi da/ko nauyin kwayoyin halitta.Girman barbashi zai rinjayi yanayin sarrafawa da adadin ɓoyayyen a cikin ƙãre samfurin yayin da nauyin kwayoyin zai yi tasiri ga crystallinity kuma saboda haka yawancin kaddarorin jiki.Dabarun sarrafawa kuma za su shafi duka crystallinity da abun ciki mara komai.

Matsakaicin ma'auni na kwayoyin halitta na polymers na kasuwanci sun bayyana suna da girma sosai kuma suna cikin kewayon 400000 zuwa 9000000. ICI rahoton cewa kayan su suna da nauyin kwayoyin halitta a cikin kewayon 500000 zuwa 5000000 da kashi kristal mafi girma fiye da 94 ~ kamar yadda aka ƙera.Abubuwan da aka kera ba su da ƙarancin crystalline.Matsayin crystallinity na ƙãre samfurin zai dogara ne akan adadin sanyaya daga yanayin aiki.Jinkirin sanyaya zai haifar da babban crystallinity tare da saurin sanyaya yana ba da kishiyar sakamako.Ƙananan kayan nauyin kwayoyin za su kasance mafi crystalline.

Ana lura da cewa polymer watsawa, wanda shine mafi girman girman barbashi da ƙananan nauyin kwayoyin halitta, yana ba da samfura tare da ingantacciyar juriya ga flexing da kuma ƙwaƙƙwaran ƙarfi.Wadannan haɓakawa suna bayyana ta hanyar samar da sifofi masu kama da fiber a cikin adadin polymer yayin aiki.