
硅橡膠是(shi)指主鏈(lian)由硅和(he)氧(yang)原(yuan)(yuan)子(zi)(zi)交替構成(cheng)(cheng),硅原(yuan)(yuan)子(zi)(zi)上通常(chang)連(lian)有兩個有機基(ji)(ji)團的(de)(de)橡(xiang)膠(jiao)。普通的(de)(de)硅橡(xiang)膠(jiao)主要(yao)由含甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)(de)硅氧(yang)鏈(lian)節組(zu)成(cheng)(cheng)。苯基(ji)(ji)的(de)(de)引入可提(ti)高(gao)硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)高(gao)、低(di)溫性(xing)能(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則(ze)可提(ti)高(gao)硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)溫及耐(nai)(nai)油性(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)耐(nai)(nai)低(di)溫性(xing)能(neng)(neng)良好,一(yi)般在-55℃下仍能(neng)(neng)工(gong)作。引入苯基(ji)(ji)后(hou),可達-73℃。硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)熱(re)性(xing)能(neng)(neng)也很突出(chu),在180℃下可長期工(gong)作,稍高(gao)于200℃也能(neng)(neng)承受數周或更長時間(jian)仍有彈性(xing),瞬時可耐(nai)(nai)300℃以上的(de)(de)高(gao)溫。硅橡(xiang)膠(jiao)的(de)(de)透(tou)氣(qi)性(xing)好,氧(yang)氣(qi)透(tou)過(guo)率在合成(cheng)(cheng)聚合物(wu)中是(shi)較(jiao)高(gao)的(de)(de)。此(ci)外,硅橡(xiang)膠(jiao)還具有生理(li)惰性(xing)、不(bu)會(hui)導致凝血的(de)(de)突出(chu)特性(xing),因(yin)此(ci)在醫用(yong)(yong)領域應(ying)用(yong)(yong)廣泛。
主(zhu)要品種
硅(gui)橡(xiang)(xiang)膠分(fen)類的方法很多,通(tong)(tong)常按(an)(an)固化(hua)前的形態分(fen)為固體(ti)硅(gui)橡(xiang)(xiang)膠和(he)液體(ti)硅(gui)橡(xiang)(xiang)膠;按(an)(an)硫化(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠,高(gao)溫(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠;按(an)(an)所用(yong)單體(ti)的不同,可分(fen)為甲(jia)(jia)基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠,甲(jia)(jia)基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠等(deng);按(an)(an)性(xing)能和(he)用(yong)途的不同又可分(fen)為通(tong)(tong)用(yong)型、超耐低溫(wen)型、超耐高(gao)溫(wen)型、高(gao)強(qiang)力型、耐油型、醫(yi)用(yong)型等(deng)等(deng)。
發展史(shi)
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)早期(qi)是由美國(guo)以三氯化(hua)鐵為催化(hua)劑合成(cheng)的(de)。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)產(chan)品(pin)問世(shi)。1948年,采用高比(bi)表(biao)面積的(de)氣相法白炭黑補強的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)研制成(cheng)功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)性能(neng)躍升到實用階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)技(ji)術的(de)基礎。從二甲基二氯硅(gui)(gui)烷(wan)合成(cheng)開始(shi)(shi)生(sheng)(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)家(jia)有美國(guo)。俄羅斯、德國(guo)、日(ri)本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)化(hua)研究(jiu)始(shi)(shi)于1957年,多家(jia)研究(jiu)所(suo)和企(qi)業(ye)陸續(xu)開發出(chu)各種硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。到2003年底,中國(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)能(neng)力為135千(qian)噸(dun)(dun),其(qi)中高溫膠(jiao)(jiao)100千(qian)噸(dun)(dun)。
高溫硫化硅橡膠(jiao)
高(gao)溫硫(liu)(liu)化(hua)硅(gui)(gui)(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)(gui)(gui)氧烷(wan)變成(cheng)彈性(xing)體的過(guo)程是(shi)(shi)經(jing)過(guo)高(gao)溫(110-170℃)硫(liu)(liu)化(hua)成(cheng)型(xing)的。它主要以高(gao)分子量的聚甲基乙烯基硅(gui)(gui)(gui)氧烷(wan)為(wei)生膠(jiao)(jiao),混入補強(qiang)填料、硫(liu)(liu)化(hua)劑(ji)(ji)(ji)等,在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)成(cheng)彈性(xing)體。硅(gui)(gui)(gui)橡膠(jiao)(jiao)的補強(qiang)主要是(shi)(shi)各種類型(xing)的白炭黑,可使硫(liu)(liu)化(hua)膠(jiao)(jiao)的強(qiang)度(du)增加(jia)數(shu)十倍(bei)。有時為(wei)了降(jiang)低成(cheng)本或改善膠(jiao)(jiao)料性(xing)能(neng)(neng)及賦予(yu)硫(liu)(liu)化(hua)膠(jiao)(jiao)各種特殊的性(xing)能(neng)(neng),也加(jia)入相應的各種添加(jia)劑(ji)(ji)(ji)。硫(liu)(liu)化(hua)劑(ji)(ji)(ji)是(shi)(shi)各種有機過(guo)氧化(hua)物(wu)或加(jia)成(cheng)反(fan)應催(cui)化(hua)劑(ji)(ji)(ji)。
加工成型方法如圖所示。一次硫(liu)化(hua)的(de)目(mu)的(de)是進行(xing)(xing)高分子(zi)鏈(lian)的(de)交聯反應(ying);二次硫(liu)化(hua)的(de)目(mu)的(de)是進行(xing)(xing)補充交聯、驅除(chu)硫(liu)化(hua)劑分解產物和其他揮發性(xing)化(hua)合物以穩(wen)定硫(liu)化(hua)膠的(de)各(ge)項性(xing)能。常用的(de)設備有開(kai)放式煉膠機、捏合機及真(zhen)空密煉機。
主要性能(neng)
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著(zhu)的(de)(de)(de)特征是(shi)高溫(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)常(chang)(chang)溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度僅(jin)是(shi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在200℃以上的(de)(de)(de)高溫(wen)(wen)環境(jing)下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持一定的(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)(biao)面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃(li)化溫(wen)(wen)度一般(ban)為(wei)(wei)-70~-50℃,特殊配(pei)方可達-100℃,表(biao)(biao)明其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對航空(kong)、宇(yu)航工業(ye)的(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)紫(zi)外(wai)線等(deng)(deng)十(shi)分穩定,在不加任何添加劑(ji)(ji)的(de)(de)(de)情況下(xia),就具(ju)(ju)(ju)有(you)優(you)良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有(you)優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下(xia)的(de)(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高溫(wen)(wen)和-50℃的(de)(de)(de)低(di)溫(wen)(wen)下(xia),其(qi)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于(yu)通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有(you)中等(deng)(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對空(kong)氣、氮、氧(yang)、二氧(yang)化碳(tan)等(deng)(deng)氣體(ti)的(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍(bei)。(8)生(sheng)理惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無毒(du),無味,無嗅,與人體(ti)組織不粘連,具(ju)(ju)(ju)有(you)抗凝(ning)血作用,對肌體(ti)組織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特別(bie)適合作為(wei)(wei)醫用材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)車工業(ye)(ye)協會統計(ji),2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車產(chan)銷(xiao)分(fen)別達到1927.18萬輛和1930.64萬輛,同比分(fen)別增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)(qi)車工業(ye)(ye)硅橡(xiang)膠的(de)(de)(de)(de)用(yong)量(liang)約達2.0萬t。根據觀研天下的(de)(de)(de)(de)新研究,增(zeng)加有(you)機硅材料在(zai)汽(qi)(qi)(qi)(qi)車零(ling)部件方面的(de)(de)(de)(de)用(yong)量(liang),可以大幅度(du)提(ti)高汽(qi)(qi)(qi)(qi)車的(de)(de)(de)(de)安全(quan)性能,因此,汽(qi)(qi)(qi)(qi)車產(chan)量(liang)和單車用(yong)量(liang)水平的(de)(de)(de)(de)提(ti)高都將(jiang)推動汽(qi)(qi)(qi)(qi)車工業(ye)(ye)對硅橡(xiang)膠需求(qiu)的(de)(de)(de)(de)增(zeng)加。國家(jia)鼓(gu)勵自(zi)主品(pin)(pin)牌(pai)的(de)(de)(de)(de)汽(qi)(qi)(qi)(qi)車發展(zhan),關鍵(jian)汽(qi)(qi)(qi)(qi)車零(ling)部件實現自(zi)主化(hua)(hua),《2012年(nian)(nian)度(du)黨政機關公務用(yong)車選用(yong)車型目錄(征(zheng)求(qiu)意見稿)》為(wei)自(zi)主品(pin)(pin)牌(pai)擴大在(zai)政府(fu)采購(gou)的(de)(de)(de)(de)市場份額(e),為(wei)改變目前國內(nei)政府(fu)采購(gou)以合(he)資品(pin)(pin)牌(pai)產(chan)品(pin)(pin)為(wei)主的(de)(de)(de)(de)局面提(ti)供(gong)了保障。促(cu)進自(zi)主品(pin)(pin)牌(pai)發展(zhan),國產(chan)汽(qi)(qi)(qi)(qi)車業(ye)(ye)的(de)(de)(de)(de)繁(fan)榮將(jiang)為(wei)汽(qi)(qi)(qi)(qi)車膠的(de)(de)(de)(de)應用(yong)提(ti)供(gong)有(you)力保障。預測未來3年(nian)(nian),我國室溫(wen)硫化(hua)(hua)硅橡(xiang)膠在(zai)汽(qi)(qi)(qi)(qi)車行業(ye)(ye)將(jiang)以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)是重要的(de)(de)非(fei)石油(you)(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),約(yue)(yue)占非(fei)石油(you)(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)消費量的(de)(de)98%。但因為石油(you)(you)(you)價格的(de)(de)大(da)幅上漲,同時我國在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)關鍵原(yuan)(yuan)料(liao)有(you)(you)機硅(gui)(gui)(gui)單體(ti)的(de)(de)生(sheng)產(chan)技術方面取得突破,有(you)(you)機硅(gui)(gui)(gui)單體(ti)的(de)(de)生(sheng)產(chan)技術在(zai)2005年前(qian)被幾家跨國公司壟斷,但目前(qian)我國已發展(zhan)成(cheng)(cheng)為全球(qiu)有(you)(you)機硅(gui)(gui)(gui)單體(ti)第1大(da)國,這2個方面原(yuan)(yuan)因使硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)價格從2011年起開(kai)始(shi)低于石油(you)(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),僅約(yue)(yue)為大(da)宗石油(you)(you)(you)基(ji)橡(xiang)(xiang)膠(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為廉(lian)價的(de)(de)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),并開(kai)始(shi)大(da)規模替代石油(you)(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)。這將極大(da)拓展(zhan)有(you)(you)機硅(gui)(gui)(gui)產(chan)業的(de)(de)市場空間,同時將帶(dai)動硅(gui)(gui)(gui)油(you)(you)(you)、硅(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)樹脂等其他有(you)(you)機硅(gui)(gui)(gui)產(chan)品的(de)(de)消費。