硅橡膠是指主(zhu)鏈由(you)硅(gui)(gui)和氧原(yuan)(yuan)子交替構成(cheng),硅(gui)(gui)原(yuan)(yuan)子上通(tong)常連有兩個(ge)有機基(ji)(ji)團的(de)橡(xiang)膠(jiao)(jiao)。普通(tong)的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)主(zhu)要由(you)含甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)硅(gui)(gui)氧鏈節(jie)組成(cheng)。苯(ben)基(ji)(ji)的(de)引入可提(ti)高(gao)(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)耐高(gao)(gao)(gao)、低溫性(xing)能(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)引入則(ze)可提(ti)高(gao)(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)耐溫及耐油性(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)耐低溫性(xing)能(neng)(neng)良好,一般在(zai)-55℃下仍能(neng)(neng)工作。引入苯(ben)基(ji)(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)耐熱(re)性(xing)能(neng)(neng)也很突出,在(zai)180℃下可長(chang)期工作,稍高(gao)(gao)(gao)于200℃也能(neng)(neng)承(cheng)受數周(zhou)或(huo)更長(chang)時間(jian)仍有彈性(xing),瞬(shun)時可耐300℃以上的(de)高(gao)(gao)(gao)溫。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)透(tou)氣性(xing)好,氧氣透(tou)過(guo)率在(zai)合成(cheng)聚(ju)合物中是較高(gao)(gao)(gao)的(de)。此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)還具(ju)有生理惰性(xing)、不會導致凝血的(de)突出特(te)性(xing),因此在(zai)醫用領域應用廣(guang)泛。
主要品種
硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)分(fen)類的(de)方法很多,通(tong)常按固化(hua)前的(de)形態分(fen)為(wei)固體硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)和液體硅(gui)橡(xiang)膠(jiao)(jiao)(jiao);按硫化(hua)溫(wen)(wen)度(du)分(fen)為(wei)室溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao),高溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao);按所(suo)用(yong)單體的(de)不同(tong),可分(fen)為(wei)甲基乙烯(xi)基硅(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲基苯基乙烯(xi)基硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)等;按性能和用(yong)途(tu)的(de)不同(tong)又可分(fen)為(wei)通(tong)用(yong)型(xing)、超耐(nai)(nai)低溫(wen)(wen)型(xing)、超耐(nai)(nai)高溫(wen)(wen)型(xing)、高強力型(xing)、耐(nai)(nai)油型(xing)、醫用(yong)型(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由美(mei)國(guo)(guo)(guo)以(yi)三(san)氯化(hua)(hua)鐵(tie)為催化(hua)(hua)劑合(he)成(cheng)的。1945年(nian),硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世。1948年(nian),采用(yong)高比表面(mian)積(ji)的氣相法白炭黑補(bu)強(qiang)的硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使(shi)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的性能躍升到(dao)實用(yong)階段,奠定(ding)了現(xian)代(dai)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術的基礎。從二甲基二氯硅(gui)烷(wan)合(he)成(cheng)開始生產(chan)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家有美(mei)國(guo)(guo)(guo)。俄羅(luo)斯、德(de)國(guo)(guo)(guo)、日本(ben)、韓國(guo)(guo)(guo)和(he)中(zhong)(zhong)國(guo)(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的工(gong)業化(hua)(hua)研(yan)究始于1957年(nian),多(duo)家研(yan)究所和(he)企業陸續(xu)開發出(chu)各種硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)能力為135千噸(dun),其中(zhong)(zhong)高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫(wen)硫(liu)(liu)化(hua)(hua)硅橡膠(jiao)是(shi)指聚(ju)(ju)硅氧(yang)(yang)烷變成(cheng)(cheng)彈性體(ti)的(de)(de)(de)過程是(shi)經過高溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)型的(de)(de)(de)。它主(zhu)要(yao)以高分子量的(de)(de)(de)聚(ju)(ju)甲基乙烯基硅氧(yang)(yang)烷為生膠(jiao),混(hun)入補(bu)強(qiang)填料、硫(liu)(liu)化(hua)(hua)劑(ji)(ji)等(deng),在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)彈性體(ti)。硅橡膠(jiao)的(de)(de)(de)補(bu)強(qiang)主(zhu)要(yao)是(shi)各(ge)種類型的(de)(de)(de)白炭(tan)黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)的(de)(de)(de)強(qiang)度增加(jia)數十倍。有時為了降(jiang)低成(cheng)(cheng)本或改善膠(jiao)料性能及賦予硫(liu)(liu)化(hua)(hua)膠(jiao)各(ge)種特殊的(de)(de)(de)性能,也加(jia)入相(xiang)應(ying)的(de)(de)(de)各(ge)種添加(jia)劑(ji)(ji)。硫(liu)(liu)化(hua)(hua)劑(ji)(ji)是(shi)各(ge)種有機過氧(yang)(yang)化(hua)(hua)物或加(jia)成(cheng)(cheng)反(fan)應(ying)催化(hua)(hua)劑(ji)(ji)。
加(jia)工成型(xing)方(fang)法如圖所示。一次硫(liu)化(hua)(hua)的(de)目的(de)是進(jin)行(xing)高分子鏈的(de)交(jiao)聯反應;二次硫(liu)化(hua)(hua)的(de)目的(de)是進(jin)行(xing)補充(chong)交(jiao)聯、驅除硫(liu)化(hua)(hua)劑分解(jie)產物(wu)和其他揮(hui)發性化(hua)(hua)合物(wu)以穩(wen)定硫(liu)化(hua)(hua)膠的(de)各項性能。常用的(de)設備有開放式煉膠機(ji)、捏合機(ji)及(ji)真空密煉機(ji)。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)特征是高(gao)(gao)溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)下硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)強度(du)僅是天然橡(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)的(de)一(yi)半,但在(zai)200℃以上的(de)高(gao)(gao)溫(wen)(wen)(wen)環境下,硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明(ming)顯(xian)變化(hua)。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)玻璃化(hua)溫(wen)(wen)(wen)度(du)一(yi)般(ban)為(wei)(wei)-70~-50℃,特殊(shu)配方可達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異(yi)。這對(dui)航空、宇航工業的(de)意(yi)義重大。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及紫(zi)外線(xian)等十分穩定,在(zai)不加(jia)(jia)任(ren)何添加(jia)(jia)劑(ji)的(de)情況下,就具(ju)有優良的(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有優異(yi)的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)下的(de)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)高(gao)(gao)溫(wen)(wen)(wen)和(he)-50℃的(de)低(di)溫(wen)(wen)(wen)下,其物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通(tong)用(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有中等的(de)耐(nai)油(you)、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體(ti)透(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣、氮(dan)、氧(yang)、二(er)氧(yang)化(hua)碳等氣體(ti)的(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)膠(jiao)(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生(sheng)理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅,與人體(ti)組織不粘連,具(ju)有抗凝血作用(yong)(yong),對(dui)肌體(ti)組織的(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別(bie)適合作為(wei)(wei)醫用(yong)(yong)材料。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)車(che)工(gong)業協(xie)會統計,2012年(nian),汽(qi)(qi)車(che)產(chan)(chan)銷分別達(da)到1927.18萬(wan)(wan)輛和(he)(he)1930.64萬(wan)(wan)輛,同比分別增長4.63%和(he)(he)4.33%,汽(qi)(qi)車(che)工(gong)業硅(gui)(gui)橡膠(jiao)的(de)(de)(de)用(yong)(yong)量約(yue)達(da)2.0萬(wan)(wan)t。根據(ju)觀研(yan)天(tian)下的(de)(de)(de)新研(yan)究,增加有機硅(gui)(gui)材料在汽(qi)(qi)車(che)零(ling)部(bu)件(jian)方面(mian)(mian)的(de)(de)(de)用(yong)(yong)量,可(ke)以(yi)大(da)幅度提(ti)高汽(qi)(qi)車(che)的(de)(de)(de)安全性能,因此,汽(qi)(qi)車(che)產(chan)(chan)量和(he)(he)單車(che)用(yong)(yong)量水平的(de)(de)(de)提(ti)高都將推動汽(qi)(qi)車(che)工(gong)業對(dui)硅(gui)(gui)橡膠(jiao)需(xu)求的(de)(de)(de)增加。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)牌(pai)的(de)(de)(de)汽(qi)(qi)車(che)發(fa)(fa)展,關鍵汽(qi)(qi)車(che)零(ling)部(bu)件(jian)實現自(zi)主(zhu)化,《2012年(nian)度黨政機關公務用(yong)(yong)車(che)選用(yong)(yong)車(che)型目錄(lu)(征求意見稿)》為自(zi)主(zhu)品(pin)(pin)牌(pai)擴大(da)在政府(fu)采購的(de)(de)(de)市場份額,為改變目前國(guo)內政府(fu)采購以(yi)合資品(pin)(pin)牌(pai)產(chan)(chan)品(pin)(pin)為主(zhu)的(de)(de)(de)局面(mian)(mian)提(ti)供了保障。促進(jin)自(zi)主(zhu)品(pin)(pin)牌(pai)發(fa)(fa)展,國(guo)產(chan)(chan)汽(qi)(qi)車(che)業的(de)(de)(de)繁(fan)榮(rong)將為汽(qi)(qi)車(che)膠(jiao)的(de)(de)(de)應(ying)用(yong)(yong)提(ti)供有力(li)保障。預(yu)測(ce)未來3年(nian),我國(guo)室溫(wen)硫化硅(gui)(gui)橡膠(jiao)在汽(qi)(qi)車(che)行(xing)業將以(yi)年(nian)均(jun)20%增長。
此外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要(yao)的(de)(de)非石(shi)油基(ji)合(he)(he)(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)油基(ji)合(he)(he)(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消費量的(de)(de)98%。但(dan)因(yin)為(wei)(wei)石(shi)油價(jia)格(ge)的(de)(de)大(da)幅上漲,同(tong)時我國在硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)關(guan)鍵原(yuan)料有機(ji)硅(gui)(gui)(gui)單體的(de)(de)生產(chan)技(ji)術(shu)方(fang)面(mian)(mian)取得突破(po),有機(ji)硅(gui)(gui)(gui)單體的(de)(de)生產(chan)技(ji)術(shu)在2005年前被(bei)幾家(jia)跨(kua)國公(gong)司(si)壟斷,但(dan)目前我國已發展(zhan)(zhan)成(cheng)(cheng)為(wei)(wei)全(quan)球有機(ji)硅(gui)(gui)(gui)單體第(di)1大(da)國,這(zhe)2個方(fang)面(mian)(mian)原(yuan)因(yin)使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)價(jia)格(ge)從2011年起(qi)開始(shi)低于石(shi)油基(ji)合(he)(he)(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅約為(wei)(wei)大(da)宗石(shi)油基(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)(wei)廉價(jia)的(de)(de)合(he)(he)(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并(bing)開始(shi)大(da)規模替代石(shi)油基(ji)合(he)(he)(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這(zhe)將(jiang)極(ji)大(da)拓展(zhan)(zhan)有機(ji)硅(gui)(gui)(gui)產(chan)業的(de)(de)市場空間(jian),同(tong)時將(jiang)帶動硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶(ou)聯(lian)劑和硅(gui)(gui)(gui)樹(shu)脂等其他有機(ji)硅(gui)(gui)(gui)產(chan)品的(de)(de)消費。