硅橡膠是指主鏈(lian)由硅和氧(yang)原(yuan)子交替構成(cheng),硅原(yuan)子上通(tong)常連(lian)有(you)兩個有(you)機基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)膠(jiao)。普通(tong)的(de)(de)(de)硅橡(xiang)(xiang)膠(jiao)主要由含甲(jia)基(ji)(ji)和少量(liang)乙烯基(ji)(ji)的(de)(de)(de)硅氧(yang)鏈(lian)節組成(cheng)。苯基(ji)(ji)的(de)(de)(de)引入可(ke)(ke)提高(gao)(gao)硅橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐高(gao)(gao)、低(di)溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)(ji)及(ji)(ji)氰基(ji)(ji)的(de)(de)(de)引入則(ze)可(ke)(ke)提高(gao)(gao)硅橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐溫(wen)及(ji)(ji)耐油(you)性(xing)能(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)耐低(di)溫(wen)性(xing)能(neng)(neng)良好,一般在(zai)-55℃下(xia)仍(reng)能(neng)(neng)工(gong)作。引入苯基(ji)(ji)后,可(ke)(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐熱性(xing)能(neng)(neng)也很突出(chu),在(zai)180℃下(xia)可(ke)(ke)長期工(gong)作,稍高(gao)(gao)于200℃也能(neng)(neng)承受(shou)數周或更(geng)長時間仍(reng)有(you)彈性(xing),瞬時可(ke)(ke)耐300℃以上的(de)(de)(de)高(gao)(gao)溫(wen)。硅橡(xiang)(xiang)膠(jiao)的(de)(de)(de)透氣性(xing)好,氧(yang)氣透過率在(zai)合成(cheng)聚合物中是較(jiao)高(gao)(gao)的(de)(de)(de)。此(ci)外,硅橡(xiang)(xiang)膠(jiao)還具有(you)生理惰性(xing)、不會導致凝血的(de)(de)(de)突出(chu)特(te)性(xing),因此(ci)在(zai)醫用(yong)領域應用(yong)廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠分(fen)類的方法很多,通常(chang)按固(gu)化(hua)前的形(xing)態分(fen)為固(gu)體硅(gui)(gui)橡(xiang)(xiang)(xiang)膠和液體硅(gui)(gui)橡(xiang)(xiang)(xiang)膠;按硫化(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠,高(gao)溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠;按所(suo)用(yong)單(dan)體的不(bu)(bu)同,可分(fen)為甲基乙(yi)烯基硅(gui)(gui)橡(xiang)(xiang)(xiang)膠,甲基苯基乙(yi)烯基硅(gui)(gui)橡(xiang)(xiang)(xiang)膠、氟(fu)硅(gui)(gui),腈(jing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠等(deng);按性能和用(yong)途的不(bu)(bu)同又可分(fen)為通用(yong)型、超耐低溫(wen)型、超耐高(gao)溫(wen)型、高(gao)強(qiang)力型、耐油(you)型、醫用(yong)型等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期是(shi)由(you)美(mei)國(guo)以三氯(lv)化(hua)(hua)鐵為催化(hua)(hua)劑合成的(de)(de)。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產(chan)品(pin)問世。1948年,采用高(gao)比表面積的(de)(de)氣(qi)相法白炭黑補強的(de)(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研制成功(gong),使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)性能躍升到實用階段,奠(dian)定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)技術的(de)(de)基(ji)礎。從二甲基(ji)二氯(lv)硅(gui)(gui)烷(wan)合成開始生(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)國(guo)家(jia)有美(mei)國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和(he)(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)工業化(hua)(hua)研究始于1957年,多家(jia)研究所和(he)(he)企業陸續開發(fa)出各種硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年底,中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)能力為135千(qian)噸(dun),其中(zhong)高(gao)溫膠(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫(wen)(wen)硫(liu)(liu)(liu)化(hua)硅橡膠(jiao)(jiao)是(shi)指聚(ju)硅氧烷變成彈性(xing)體(ti)(ti)的(de)過程是(shi)經過高(gao)溫(wen)(wen)(110-170℃)硫(liu)(liu)(liu)化(hua)成型的(de)。它主要(yao)以高(gao)分(fen)子量的(de)聚(ju)甲(jia)基(ji)乙烯(xi)基(ji)硅氧烷為生膠(jiao)(jiao),混入(ru)補(bu)(bu)強填料、硫(liu)(liu)(liu)化(hua)劑等,在加(jia)(jia)熱加(jia)(jia)壓下硫(liu)(liu)(liu)化(hua)成彈性(xing)體(ti)(ti)。硅橡膠(jiao)(jiao)的(de)補(bu)(bu)強主要(yao)是(shi)各種(zhong)類型的(de)白炭(tan)黑,可使(shi)硫(liu)(liu)(liu)化(hua)膠(jiao)(jiao)的(de)強度增加(jia)(jia)數十倍(bei)。有時為了降低成本或改善膠(jiao)(jiao)料性(xing)能(neng)及賦予硫(liu)(liu)(liu)化(hua)膠(jiao)(jiao)各種(zhong)特殊(shu)的(de)性(xing)能(neng),也加(jia)(jia)入(ru)相(xiang)應的(de)各種(zhong)添加(jia)(jia)劑。硫(liu)(liu)(liu)化(hua)劑是(shi)各種(zhong)有機過氧化(hua)物或加(jia)(jia)成反(fan)應催化(hua)劑。
加工成型方法如圖所示(shi)。一次(ci)硫化(hua)(hua)的(de)目的(de)是(shi)進行(xing)高(gao)分(fen)子鏈(lian)的(de)交(jiao)聯反應;二次(ci)硫化(hua)(hua)的(de)目的(de)是(shi)進行(xing)補充(chong)交(jiao)聯、驅除硫化(hua)(hua)劑分(fen)解產物(wu)(wu)和其他(ta)揮發性化(hua)(hua)合物(wu)(wu)以穩(wen)定硫化(hua)(hua)膠的(de)各項性能。常用的(de)設備有開放式煉(lian)膠機(ji)(ji)、捏合機(ji)(ji)及(ji)真空密煉(lian)機(ji)(ji)。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)顯著的(de)特(te)征是高(gao)溫(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)強(qiang)度(du)僅(jin)是天然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)或某(mou)些(xie)合成橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)一半(ban),但(dan)在(zai)200℃以上的(de)高(gao)溫(wen)環境下(xia)(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)仍(reng)能(neng)(neng)(neng)保持一定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面(mian)硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)玻(bo)璃化溫(wen)度(du)一般為-70~-50℃,特(te)殊配(pei)方可達-100℃,表明其(qi)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這(zhe)對航(hang)空(kong)、宇航(hang)工業的(de)意義重(zhong)大。(3)耐(nai)(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及紫(zi)外線(xian)等(deng)十分穩(wen)定,在(zai)不加任何(he)添加劑(ji)(ji)的(de)情況下(xia)(xia),就具(ju)有優(you)良的(de)耐(nai)(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有優(you)異的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)(nai)(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)(nai)(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)常溫(wen)下(xia)(xia)的(de)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)在(zai)150℃的(de)高(gao)溫(wen)和-50℃的(de)低(di)溫(wen)下(xia)(xia),其(qi)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)(nai)(nai)(nai)(nai)油(you)及化學(xue)試(shi)劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有中等(deng)的(de)耐(nai)(nai)(nai)(nai)(nai)油(you)、耐(nai)(nai)(nai)(nai)(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)對空(kong)氣(qi)、氮、氧(yang)、二氧(yang)化碳(tan)等(deng)氣(qi)體(ti)的(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)出30-50倍。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)無毒,無味(wei),無嗅,與人體(ti)組織(zhi)不粘連,具(ju)有抗凝血作用(yong),對肌(ji)體(ti)組織(zhi)的(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作為醫用(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(xie)會統(tong)計,2012年(nian),汽(qi)(qi)(qi)(qi)車(che)產銷(xiao)分(fen)別(bie)達到1927.18萬輛和(he)1930.64萬輛,同比分(fen)別(bie)增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)工業(ye)硅橡膠(jiao)的(de)(de)用(yong)(yong)量(liang)約達2.0萬t。根據觀研(yan)天(tian)下的(de)(de)新研(yan)究,增(zeng)加(jia)有機(ji)硅材料(liao)在(zai)汽(qi)(qi)(qi)(qi)車(che)零(ling)部件方面的(de)(de)用(yong)(yong)量(liang),可以大幅(fu)度提(ti)高(gao)汽(qi)(qi)(qi)(qi)車(che)的(de)(de)安全(quan)性(xing)能(neng),因(yin)此(ci),汽(qi)(qi)(qi)(qi)車(che)產量(liang)和(he)單車(che)用(yong)(yong)量(liang)水平的(de)(de)提(ti)高(gao)都將推動汽(qi)(qi)(qi)(qi)車(che)工業(ye)對(dui)硅橡膠(jiao)需求的(de)(de)增(zeng)加(jia)。國(guo)(guo)家鼓勵(li)自(zi)(zi)主品(pin)(pin)牌(pai)的(de)(de)汽(qi)(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)(qi)車(che)零(ling)部件實現自(zi)(zi)主化(hua)(hua),《2012年(nian)度黨政(zheng)機(ji)關公(gong)務用(yong)(yong)車(che)選用(yong)(yong)車(che)型目(mu)(mu)錄(lu)(征求意(yi)見稿)》為自(zi)(zi)主品(pin)(pin)牌(pai)擴大在(zai)政(zheng)府采購(gou)的(de)(de)市(shi)場(chang)份額,為改變目(mu)(mu)前國(guo)(guo)內政(zheng)府采購(gou)以合資品(pin)(pin)牌(pai)產品(pin)(pin)為主的(de)(de)局面提(ti)供了保障(zhang)。促(cu)進自(zi)(zi)主品(pin)(pin)牌(pai)發展,國(guo)(guo)產汽(qi)(qi)(qi)(qi)車(che)業(ye)的(de)(de)繁榮將為汽(qi)(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)應用(yong)(yong)提(ti)供有力保障(zhang)。預測(ce)未(wei)來3年(nian),我國(guo)(guo)室(shi)溫硫化(hua)(hua)硅橡膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)車(che)行業(ye)將以年(nian)均(jun)20%增(zeng)長。
此外,硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是(shi)重(zhong)要(yao)的(de)(de)(de)非石(shi)(shi)油基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消(xiao)費量(liang)的(de)(de)(de)98%。但(dan)因為(wei)石(shi)(shi)油價格的(de)(de)(de)大(da)(da)(da)(da)幅(fu)上漲,同時我(wo)國(guo)在硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關鍵(jian)原料有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技術(shu)(shu)方面(mian)(mian)取得突破,有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技術(shu)(shu)在2005年(nian)(nian)前被幾(ji)家跨國(guo)公司壟(long)斷,但(dan)目前我(wo)國(guo)已發(fa)展(zhan)成(cheng)為(wei)全(quan)球有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體第1大(da)(da)(da)(da)國(guo),這2個方面(mian)(mian)原因使硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價格從2011年(nian)(nian)起開(kai)始(shi)低于石(shi)(shi)油基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大(da)(da)(da)(da)宗石(shi)(shi)油基橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)為(wei)廉(lian)價的(de)(de)(de)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并開(kai)始(shi)大(da)(da)(da)(da)規模替代石(shi)(shi)油基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)(da)(da)(da)拓展(zhan)有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)業的(de)(de)(de)市(shi)場空(kong)間,同時將帶動硅(gui)(gui)(gui)(gui)油、硅(gui)(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)(gui)樹脂等其他(ta)有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)品的(de)(de)(de)消(xiao)費。