硅橡膠是指(zhi)主鏈由(you)硅(gui)(gui)(gui)和氧(yang)原子交替構成(cheng)(cheng),硅(gui)(gui)(gui)原子上通常連有(you)兩(liang)個有(you)機基(ji)(ji)團的(de)(de)橡(xiang)膠。普通的(de)(de)硅(gui)(gui)(gui)橡(xiang)膠主要由(you)含甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)(de)硅(gui)(gui)(gui)氧(yang)鏈節組成(cheng)(cheng)。苯基(ji)(ji)的(de)(de)引入可提(ti)高硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)耐(nai)(nai)(nai)(nai)高、低溫(wen)(wen)(wen)性(xing)(xing)能(neng),三氟(fu)丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則可提(ti)高硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)耐(nai)(nai)(nai)(nai)溫(wen)(wen)(wen)及耐(nai)(nai)(nai)(nai)油性(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠耐(nai)(nai)(nai)(nai)低溫(wen)(wen)(wen)性(xing)(xing)能(neng)良好,一般在-55℃下仍(reng)能(neng)工(gong)作。引入苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)耐(nai)(nai)(nai)(nai)熱性(xing)(xing)能(neng)也(ye)很突出,在180℃下可長期工(gong)作,稍高于200℃也(ye)能(neng)承受(shou)數周或(huo)更(geng)長時間(jian)仍(reng)有(you)彈性(xing)(xing),瞬(shun)時可耐(nai)(nai)(nai)(nai)300℃以上的(de)(de)高溫(wen)(wen)(wen)。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)透氣性(xing)(xing)好,氧(yang)氣透過率在合成(cheng)(cheng)聚合物中(zhong)是較高的(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)膠還具有(you)生理(li)惰性(xing)(xing)、不(bu)會導致凝血的(de)(de)突出特性(xing)(xing),因此在醫用領域(yu)應(ying)用廣泛。
主要品種
硅(gui)橡(xiang)膠(jiao)(jiao)分類(lei)的方法很多,通常按(an)固化(hua)(hua)前的形態分為固體硅(gui)橡(xiang)膠(jiao)(jiao)和液體硅(gui)橡(xiang)膠(jiao)(jiao);按(an)硫(liu)化(hua)(hua)溫(wen)度分為室溫(wen)硫(liu)化(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫(liu)化(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao);按(an)所(suo)用單體的不同(tong),可分為甲基(ji)乙烯(xi)基(ji)硅(gui)橡(xiang)膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)橡(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)膠(jiao)(jiao)等(deng);按(an)性能和用途(tu)的不同(tong)又可分為通用型、超(chao)耐(nai)(nai)低溫(wen)型、超(chao)耐(nai)(nai)高(gao)溫(wen)型、高(gao)強力型、耐(nai)(nai)油型、醫用型等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)(guo)(guo)以三氯(lv)化鐵為催化劑合(he)成(cheng)(cheng)的。1945年,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)品問(wen)世。1948年,采用高比表(biao)面積的氣(qi)相(xiang)法白炭(tan)黑補強的硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成(cheng)(cheng)功,使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的性(xing)能(neng)躍升(sheng)到(dao)(dao)實用階段,奠定了現代(dai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)技術的基礎。從二(er)(er)甲基二(er)(er)氯(lv)硅(gui)(gui)(gui)烷合(he)成(cheng)(cheng)開始生(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家有(you)美國(guo)(guo)(guo)。俄羅斯、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中國(guo)(guo)(guo)等。中國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的工業化研究始于1957年,多家研究所(suo)和企業陸續開發出(chu)各種硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)(dao)2003年底,中國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)能(neng)力(li)為135千噸(dun),其中高溫(wen)膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫(wen)(wen)硫化(hua)硅橡(xiang)膠(jiao)(jiao)(jiao)是(shi)指聚(ju)硅氧(yang)烷變成彈(dan)性體的(de)(de)過(guo)程是(shi)經過(guo)高溫(wen)(wen)(110-170℃)硫化(hua)成型(xing)(xing)的(de)(de)。它主要以高分(fen)子量(liang)的(de)(de)聚(ju)甲(jia)基(ji)乙(yi)烯基(ji)硅氧(yang)烷為(wei)生膠(jiao)(jiao)(jiao),混入(ru)補(bu)強(qiang)填(tian)料、硫化(hua)劑(ji)等,在加(jia)熱(re)加(jia)壓下硫化(hua)成彈(dan)性體。硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)補(bu)強(qiang)主要是(shi)各(ge)種類型(xing)(xing)的(de)(de)白炭黑,可(ke)使硫化(hua)膠(jiao)(jiao)(jiao)的(de)(de)強(qiang)度(du)增(zeng)加(jia)數十倍。有時為(wei)了(le)降低成本或改善膠(jiao)(jiao)(jiao)料性能(neng)及賦予硫化(hua)膠(jiao)(jiao)(jiao)各(ge)種特殊的(de)(de)性能(neng),也加(jia)入(ru)相(xiang)應的(de)(de)各(ge)種添(tian)加(jia)劑(ji)。硫化(hua)劑(ji)是(shi)各(ge)種有機過(guo)氧(yang)化(hua)物(wu)或加(jia)成反(fan)應催化(hua)劑(ji)。
加(jia)工成型方法如圖所示。一次硫(liu)(liu)化(hua)(hua)的(de)目(mu)的(de)是進行(xing)高分(fen)子鏈的(de)交聯(lian)反(fan)應;二次硫(liu)(liu)化(hua)(hua)的(de)目(mu)的(de)是進行(xing)補充交聯(lian)、驅(qu)除硫(liu)(liu)化(hua)(hua)劑分(fen)解產物和(he)其(qi)他揮發性化(hua)(hua)合物以(yi)穩定硫(liu)(liu)化(hua)(hua)膠(jiao)的(de)各(ge)項性能。常(chang)用的(de)設備有開放式(shi)煉膠(jiao)機、捏合機及真空(kong)密煉機。
主要性能
(1)高(gao)(gao)(gao)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)特(te)征是(shi)高(gao)(gao)(gao)溫(wen)(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度僅是(shi)天(tian)(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)一半,但(dan)在(zai)(zai)200℃以(yi)上的(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持一定(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面(mian)硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯(xian)變化(hua)。(2)低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃(li)化(hua)溫(wen)(wen)(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方(fang)可達-100℃,表明其低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)異(yi)。這對(dui)航空(kong)、宇航工業的(de)(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧、臭氧及紫外線等十分穩定(ding),在(zai)(zai)不加任何添(tian)加劑(ji)(ji)的(de)(de)(de)(de)情(qing)況(kuang)下,就(jiu)具(ju)(ju)(ju)有(you)(you)優(you)(you)良(liang)的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有(you)(you)優(you)(you)異(yi)的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下的(de)(de)(de)(de)物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通用(yong)(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)(zai)150℃的(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)低溫(wen)(wen)(wen)(wen)(wen)下,其物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)于通用(yong)(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)(you)及化(hua)學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有(you)(you)中等的(de)(de)(de)(de)耐(nai)油(you)(you)、耐(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體(ti)(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空(kong)氣、氮、氧、二氧化(hua)碳等氣體(ti)(ti)的(de)(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)(gao)(gao)出30-50倍(bei)。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)(ti)組織不粘(zhan)連,具(ju)(ju)(ju)有(you)(you)抗凝血作用(yong)(yong)(yong),對(dui)肌體(ti)(ti)組織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特(te)別(bie)適合作為醫用(yong)(yong)(yong)材(cai)料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)工業(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車(che)產銷分別達到(dao)1927.18萬(wan)(wan)(wan)輛和1930.64萬(wan)(wan)(wan)輛,同比分別增長(chang)4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)工業(ye)硅(gui)橡(xiang)膠(jiao)的(de)(de)用(yong)量(liang)約達2.0萬(wan)(wan)(wan)t。根據觀(guan)研天(tian)下的(de)(de)新(xin)研究,增加(jia)有機(ji)(ji)硅(gui)材料在汽(qi)(qi)(qi)(qi)車(che)零(ling)部件(jian)方(fang)面的(de)(de)用(yong)量(liang),可(ke)以大幅度提(ti)(ti)高汽(qi)(qi)(qi)(qi)車(che)的(de)(de)安(an)全性能,因(yin)此,汽(qi)(qi)(qi)(qi)車(che)產量(liang)和單車(che)用(yong)量(liang)水平的(de)(de)提(ti)(ti)高都將推動汽(qi)(qi)(qi)(qi)車(che)工業(ye)對硅(gui)橡(xiang)膠(jiao)需求的(de)(de)增加(jia)。國(guo)(guo)家鼓勵自(zi)主品(pin)牌的(de)(de)汽(qi)(qi)(qi)(qi)車(che)發展,關(guan)鍵汽(qi)(qi)(qi)(qi)車(che)零(ling)部件(jian)實現自(zi)主化,《2012年(nian)(nian)度黨(dang)政機(ji)(ji)關(guan)公(gong)務用(yong)車(che)選用(yong)車(che)型目錄(征求意見(jian)稿)》為(wei)自(zi)主品(pin)牌擴大在政府采購(gou)的(de)(de)市(shi)場份額(e),為(wei)改(gai)變(bian)目前(qian)國(guo)(guo)內政府采購(gou)以合資(zi)品(pin)牌產品(pin)為(wei)主的(de)(de)局(ju)面提(ti)(ti)供了保障。促進自(zi)主品(pin)牌發展,國(guo)(guo)產汽(qi)(qi)(qi)(qi)車(che)業(ye)的(de)(de)繁(fan)榮將為(wei)汽(qi)(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)應用(yong)提(ti)(ti)供有力保障。預測未來(lai)3年(nian)(nian),我國(guo)(guo)室溫硫化硅(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)(qi)車(che)行業(ye)將以年(nian)(nian)均20%增長(chang)。
此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)是重(zhong)要的(de)(de)(de)(de)非石(shi)(shi)油(you)基合(he)(he)(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),約(yue)占非石(shi)(shi)油(you)基合(he)(he)(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)消費量的(de)(de)(de)(de)98%。但(dan)因(yin)為(wei)石(shi)(shi)油(you)價格的(de)(de)(de)(de)大(da)幅上漲,同時我國(guo)在(zai)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)關鍵(jian)原料有機硅(gui)(gui)單體(ti)的(de)(de)(de)(de)生產(chan)技術方面取得突破(po),有機硅(gui)(gui)單體(ti)的(de)(de)(de)(de)生產(chan)技術在(zai)2005年前被(bei)幾(ji)家跨國(guo)公司(si)壟斷,但(dan)目前我國(guo)已發(fa)展成(cheng)(cheng)為(wei)全球有機硅(gui)(gui)單體(ti)第1大(da)國(guo),這2個方面原因(yin)使(shi)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)價格從2011年起開始(shi)低于石(shi)(shi)油(you)基合(he)(he)(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),僅(jin)約(yue)為(wei)大(da)宗(zong)石(shi)(shi)油(you)基橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉價的(de)(de)(de)(de)合(he)(he)(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),并開始(shi)大(da)規模(mo)替代石(shi)(shi)油(you)基合(he)(he)(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。這將極大(da)拓展有機硅(gui)(gui)產(chan)業的(de)(de)(de)(de)市場空間,同時將帶(dai)動硅(gui)(gui)油(you)、硅(gui)(gui)烷偶(ou)聯劑和硅(gui)(gui)樹(shu)脂(zhi)等(deng)其(qi)他有機硅(gui)(gui)產(chan)品的(de)(de)(de)(de)消費。