
硅橡膠是指主(zhu)鏈(lian)由硅(gui)(gui)(gui)和氧原(yuan)子交替(ti)構(gou)成,硅(gui)(gui)(gui)原(yuan)子上通常連有(you)(you)兩個有(you)(you)機基(ji)(ji)(ji)團的(de)(de)(de)橡(xiang)膠。普通的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠主(zhu)要(yao)由含甲基(ji)(ji)(ji)和少(shao)量(liang)乙烯基(ji)(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧鏈(lian)節(jie)組成。苯基(ji)(ji)(ji)的(de)(de)(de)引(yin)入(ru)(ru)可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐(nai)(nai)高(gao)、低溫(wen)性(xing)(xing)(xing)能,三氟(fu)丙基(ji)(ji)(ji)及氰基(ji)(ji)(ji)的(de)(de)(de)引(yin)入(ru)(ru)則可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)膠耐(nai)(nai)低溫(wen)性(xing)(xing)(xing)能良(liang)好(hao),一般在(zai)(zai)-55℃下仍能工作。引(yin)入(ru)(ru)苯基(ji)(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐(nai)(nai)熱性(xing)(xing)(xing)能也(ye)很突出(chu),在(zai)(zai)180℃下可(ke)長(chang)期工作,稍高(gao)于200℃也(ye)能承受(shou)數周(zhou)或(huo)更長(chang)時(shi)間仍有(you)(you)彈(dan)性(xing)(xing)(xing),瞬時(shi)可(ke)耐(nai)(nai)300℃以上的(de)(de)(de)高(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)透氣性(xing)(xing)(xing)好(hao),氧氣透過率在(zai)(zai)合成聚(ju)合物(wu)中(zhong)是較(jiao)高(gao)的(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)膠還具有(you)(you)生理(li)惰(duo)性(xing)(xing)(xing)、不(bu)會導致凝血的(de)(de)(de)突出(chu)特性(xing)(xing)(xing),因此在(zai)(zai)醫用領域應用廣(guang)泛。
主要品種
硅橡(xiang)膠分(fen)類(lei)的方法很多(duo),通(tong)常按固化(hua)
前(qian)的(de)形態分(fen)(fen)為固體(ti)(ti)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)和液體(ti)(ti)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)硫(liu)化溫(wen)度分(fen)(fen)為室溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),高溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)所用單體(ti)(ti)的(de)不同(tong),可分(fen)(fen)為甲基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)等(deng);按(an)性能(neng)和用途的(de)不同(tong)又可分(fen)(fen)為通用型、超(chao)(chao)耐低溫(wen)型、超(chao)(chao)耐高溫(wen)型、高強力型、耐油型、醫用型等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)(guo)(guo)以三氯化鐵為催化劑合成(cheng)(cheng)的。1945年(nian)(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世。1948年(nian)(nian),采用高比表面積的氣相法白炭(tan)黑補強的硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的性能(neng)躍升(sheng)到實用階(jie)段,奠(dian)定了(le)現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術的基礎。從二甲基二氯硅(gui)(gui)烷合成(cheng)(cheng)開始生產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家(jia)有美國(guo)(guo)(guo)。俄羅斯(si)、德(de)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)橡(xiang)膠(jiao)(jiao)(jiao)的工業化研(yan)究始于1957年(nian)(nian),多家(jia)研(yan)究所和企業陸(lu)續開發出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底(di),中國(guo)(guo)(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)能(neng)力為135千噸(dun),其中高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫(wen)硫化(hua)硅橡膠
高溫(wen)硫(liu)(liu)化(hua)(hua)(hua)硅(gui)橡膠(jiao)是指(zhi)聚(ju)硅(gui)氧(yang)烷變成(cheng)(cheng)彈性(xing)體的(de)(de)(de)過(guo)程(cheng)是經(jing)過(guo)高溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)型的(de)(de)(de)。它(ta)主要以高分子量的(de)(de)(de)聚(ju)甲基乙烯基硅(gui)氧(yang)烷為(wei)生膠(jiao),混入補強填料、硫(liu)(liu)化(hua)(hua)(hua)劑等,在加(jia)(jia)熱加(jia)(jia)壓下硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)彈性(xing)體。硅(gui)橡膠(jiao)的(de)(de)(de)補強主要是各種類型的(de)(de)(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)的(de)(de)(de)強度增加(jia)(jia)數十(shi)倍。有(you)時為(wei)了降低成(cheng)(cheng)本或(huo)(huo)改善膠(jiao)料性(xing)能及(ji)賦(fu)予硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)各種特殊的(de)(de)(de)性(xing)能,也加(jia)(jia)入相應(ying)的(de)(de)(de)各種添加(jia)(jia)劑。硫(liu)(liu)化(hua)(hua)(hua)劑是各種有(you)機過(guo)氧(yang)化(hua)(hua)(hua)物或(huo)(huo)加(jia)(jia)成(cheng)(cheng)反應(ying)催化(hua)(hua)(hua)劑。
加工成型方(fang)法如圖所示。一次硫化的(de)(de)目(mu)的(de)(de)是進行高分子鏈的(de)(de)交聯(lian)反(fan)應;二次硫化的(de)(de)目(mu)的(de)(de)是進行補充交聯(lian)、驅除硫化劑分解產物和(he)其他揮發性(xing)化合(he)物以穩定硫化膠的(de)(de)各(ge)項(xiang)性(xing)能。常用的(de)(de)設備有開放式煉(lian)膠機、捏合(he)機及(ji)真(zhen)空密煉(lian)機。
主要(yao)性(xing)能
(1)高(gao)(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯著的(de)(de)特征是高(gao)(gao)溫(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)常溫(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)強度僅是天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某些(xie)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)一半(ban),但在(zai)200℃以上的(de)(de)高(gao)(gao)溫(wen)(wen)環(huan)境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)保持一定(ding)的(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明(ming)顯變化。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)玻璃(li)化溫(wen)(wen)度一般為(wei)(wei)-70~-50℃,特殊配方可(ke)達-100℃,表(biao)明(ming)其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這(zhe)對航空、宇(yu)航工業的(de)(de)意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵對氧、臭氧及紫(zi)外線等十分穩(wen)定(ding),在(zai)不加任(ren)何添加劑(ji)(ji)的(de)(de)情況下,就具(ju)有優(you)良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常溫(wen)(wen)下的(de)(de)物(wu)理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但在(zai)150℃的(de)(de)高(gao)(gao)溫(wen)(wen)和(he)-50℃的(de)(de)低(di)溫(wen)(wen)下,其(qi)物(wu)理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于(yu)通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)油及化學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有中等的(de)(de)耐(nai)油、耐(nai)溶(rong)劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對空氣(qi)、氮、氧、二氧化碳等氣(qi)體的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組織不粘連,具(ju)有抗凝(ning)血(xue)作(zuo)用(yong)(yong),對肌(ji)體組織的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別適(shi)合(he)作(zuo)為(wei)(wei)醫用(yong)(yong)材料。
硅橡膠(jiao)的(de)用(yong)量
據中國(guo)(guo)汽(qi)(qi)車工(gong)業協會統計,2012年,汽(qi)(qi)車產銷分(fen)別達到1927.18萬輛(liang)和1930.64萬輛(liang),同(tong)比分(fen)別增(zeng)(zeng)(zeng)長4.63%和4.33%,汽(qi)(qi)車工(gong)業硅橡(xiang)膠(jiao)的用(yong)量(liang)約達2.0萬t。根據觀研(yan)天下的新研(yan)究,增(zeng)(zeng)(zeng)加有(you)(you)機(ji)硅材料(liao)在(zai)汽(qi)(qi)車零部件(jian)方面的用(yong)量(liang),可(ke)以大幅度提(ti)(ti)高(gao)汽(qi)(qi)車的安全性(xing)能,因此,汽(qi)(qi)車產量(liang)和單車用(yong)量(liang)水平的提(ti)(ti)高(gao)都將(jiang)推動汽(qi)(qi)車工(gong)業對硅橡(xiang)膠(jiao)需求的增(zeng)(zeng)(zeng)加。國(guo)(guo)家鼓(gu)勵自(zi)(zi)主品牌(pai)的汽(qi)(qi)車發展,關(guan)鍵(jian)汽(qi)(qi)車零部件(jian)實現自(zi)(zi)主化,《2012年度黨(dang)政機(ji)關(guan)公務用(yong)車選用(yong)車型目(mu)錄(征求意見稿)》為自(zi)(zi)主品牌(pai)擴大在(zai)政府(fu)采購(gou)的市場(chang)份額,為改變目(mu)前國(guo)(guo)內政府(fu)采購(gou)以合(he)資品牌(pai)產品為主的局面提(ti)(ti)供了保(bao)障(zhang)。促進(jin)自(zi)(zi)主品牌(pai)發展,國(guo)(guo)產汽(qi)(qi)車業的繁榮將(jiang)為汽(qi)(qi)車膠(jiao)的應用(yong)提(ti)(ti)供有(you)(you)力保(bao)障(zhang)。預測未來3年,我(wo)國(guo)(guo)室溫硫化硅橡(xiang)膠(jiao)在(zai)汽(qi)(qi)車行業將(jiang)以年均20%增(zeng)(zeng)(zeng)長。
此外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重要的非石(shi)油基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約(yue)占非石(shi)油基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消費量的98%。但(dan)因為石(shi)油價格(ge)的大幅上漲,同時我國(guo)在(zai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的關(guan)鍵原(yuan)料(liao)有(you)機(ji)硅(gui)單(dan)體的生產技(ji)術(shu)方面取(qu)得突破,有(you)機(ji)硅(gui)單(dan)體的生產技(ji)術(shu)在(zai)2005年(nian)前(qian)(qian)被幾(ji)家跨國(guo)公司壟(long)斷,但(dan)目前(qian)(qian)我國(guo)已發展成(cheng)為全球有(you)機(ji)硅(gui)單(dan)體第1大國(guo),這2個方面原(yuan)因使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的價格(ge)從(cong)2011年(nian)起開始(shi)低于(yu)石(shi)油基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約(yue)為大宗石(shi)油基橡(xiang)(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)為廉價的合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并(bing)開始(shi)大規模替代石(shi)油基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將極大拓展有(you)機(ji)硅(gui)產業的市場空間,同時將帶動硅(gui)油、硅(gui)烷偶(ou)聯劑和硅(gui)樹脂(zhi)等其(qi)他有(you)機(ji)硅(gui)產品的消費。