硅橡膠是指(zhi)主鏈由硅(gui)(gui)(gui)和氧原子(zi)交替構(gou)成,硅(gui)(gui)(gui)原子(zi)上通常連(lian)有(you)兩個有(you)機基(ji)團(tuan)的橡(xiang)(xiang)(xiang)膠(jiao)。普通的硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)主要由含甲基(ji)和少量乙(yi)烯基(ji)的硅(gui)(gui)(gui)氧鏈節組成。苯基(ji)的引入可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)高(gao)、低(di)溫性(xing)(xing)能(neng),三氟丙基(ji)及(ji)氰基(ji)的引入則可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)溫及(ji)耐(nai)(nai)油(you)性(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)耐(nai)(nai)低(di)溫性(xing)(xing)能(neng)良好(hao),一般在(zai)-55℃下仍能(neng)工(gong)作(zuo)。引入苯基(ji)后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)熱性(xing)(xing)能(neng)也很突(tu)出(chu)(chu),在(zai)180℃下可(ke)長(chang)期工(gong)作(zuo),稍高(gao)于200℃也能(neng)承受數周或更長(chang)時(shi)(shi)間(jian)仍有(you)彈性(xing)(xing),瞬(shun)時(shi)(shi)可(ke)耐(nai)(nai)300℃以上的高(gao)溫。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的透(tou)氣(qi)性(xing)(xing)好(hao),氧氣(qi)透(tou)過率(lv)在(zai)合(he)成聚合(he)物中是較高(gao)的。此(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)還具有(you)生理惰(duo)性(xing)(xing)、不會(hui)導(dao)致凝血的突(tu)出(chu)(chu)特性(xing)(xing),因此(ci)在(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)分類的方(fang)法很多,通(tong)常按固化(hua)前的形態分為(wei)(wei)固體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)和(he)液(ye)體硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按硫(liu)化(hua)溫(wen)度分為(wei)(wei)室溫(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按所(suo)用單體的不(bu)同,可分為(wei)(wei)甲基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)等(deng);按性能和(he)用途(tu)的不(bu)同又(you)可分為(wei)(wei)通(tong)用型(xing)(xing)、超(chao)耐低溫(wen)型(xing)(xing)、超(chao)耐高(gao)溫(wen)型(xing)(xing)、高(gao)強力(li)型(xing)(xing)、耐油(you)型(xing)(xing)、醫用型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期(qi)是(shi)由(you)美國(guo)(guo)以三氯(lv)(lv)化鐵為(wei)催化劑合成的(de)(de)。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)(chan)品問世。1948年(nian),采(cai)用高比表(biao)面(mian)積的(de)(de)氣相法白(bai)炭黑補強的(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)研(yan)制成功,使硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)性能躍升到實用階段(duan),奠(dian)定了現代硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)(chan)技術(shu)的(de)(de)基礎。從二甲(jia)基二氯(lv)(lv)硅(gui)(gui)(gui)烷合成開始(shi)生產(chan)(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)國(guo)(guo)家有美國(guo)(guo)。俄羅(luo)斯、德國(guo)(guo)、日(ri)本、韓國(guo)(guo)和中國(guo)(guo)等(deng)。中國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)工(gong)業化研(yan)究(jiu)始(shi)于1957年(nian),多家研(yan)究(jiu)所和企(qi)業陸續開發出各種硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底,中國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)(chan)能力為(wei)135千噸(dun),其中高溫(wen)膠(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫(wen)硫(liu)(liu)化(hua)(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)氧烷變成(cheng)(cheng)彈(dan)性體(ti)的過程是(shi)(shi)經過高溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)型的。它主(zhu)要(yao)以高分(fen)子量的聚甲基乙(yi)烯基硅(gui)氧烷為生膠(jiao)(jiao),混(hun)入(ru)補強填(tian)料、硫(liu)(liu)化(hua)(hua)(hua)劑(ji)等,在(zai)加(jia)熱(re)加(jia)壓下硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)彈(dan)性體(ti)。硅(gui)橡(xiang)膠(jiao)(jiao)的補強主(zhu)要(yao)是(shi)(shi)各種類型的白炭黑(hei),可(ke)使硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的強度增加(jia)數十倍(bei)。有時為了降低成(cheng)(cheng)本或改善膠(jiao)(jiao)料性能(neng)及(ji)賦予(yu)硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各種特殊的性能(neng),也(ye)加(jia)入(ru)相應(ying)的各種添加(jia)劑(ji)。硫(liu)(liu)化(hua)(hua)(hua)劑(ji)是(shi)(shi)各種有機過氧化(hua)(hua)(hua)物或加(jia)成(cheng)(cheng)反應(ying)催化(hua)(hua)(hua)劑(ji)。
加工(gong)成(cheng)型方(fang)法如圖(tu)所示。一次硫(liu)(liu)(liu)化(hua)(hua)的(de)目的(de)是進行(xing)高分(fen)子鏈的(de)交聯(lian)反應;二(er)次硫(liu)(liu)(liu)化(hua)(hua)的(de)目的(de)是進行(xing)補充交聯(lian)、驅除(chu)硫(liu)(liu)(liu)化(hua)(hua)劑分(fen)解產物和(he)其(qi)他揮發(fa)性化(hua)(hua)合物以(yi)穩定硫(liu)(liu)(liu)化(hua)(hua)膠的(de)各項性能。常用的(de)設備有(you)開放(fang)式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特征是(shi)高溫(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)下(xia)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅是(shi)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或(huo)某(mou)些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但在(zai)200℃以上的(de)(de)(de)(de)(de)高溫(wen)(wen)環境下(xia),硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面(mian)硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明(ming)顯變(bian)化。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)度(du)一(yi)般為-70~-50℃,特殊(shu)配方可(ke)達-100℃,表(biao)明(ming)其(qi)(qi)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這(zhe)對(dui)航空(kong)、宇(yu)航工業的(de)(de)(de)(de)(de)意義重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及(ji)紫(zi)外線等十分(fen)穩(wen)定(ding),在(zai)不(bu)加任何添加劑的(de)(de)(de)(de)(de)情況下(xia),就具有優(you)良的(de)(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有優(you)異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)下(xia)的(de)(de)(de)(de)(de)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)(de)(de)高溫(wen)(wen)和(he)-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)下(xia),其(qi)(qi)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于(yu)通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有中等的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)下(xia)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空(kong)氣(qi)(qi)、氮、氧(yang)、二氧(yang)化碳等氣(qi)(qi)體(ti)(ti)的(de)(de)(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍(bei)。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無毒(du),無味,無嗅,與人體(ti)(ti)組(zu)織不(bu)粘連,具有抗(kang)凝血作(zuo)用(yong),對(dui)肌體(ti)(ti)組(zu)織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少(shao)。特別適合作(zuo)為醫(yi)用(yong)材料。
硅橡膠的用量
據中國汽(qi)車(che)(che)(che)工(gong)(gong)業(ye)協會統計,2012年(nian),汽(qi)車(che)(che)(che)產銷分別(bie)達(da)到(dao)1927.18萬輛(liang)和1930.64萬輛(liang),同(tong)比分別(bie)增(zeng)長(chang)4.63%和4.33%,汽(qi)車(che)(che)(che)工(gong)(gong)業(ye)硅橡膠的用(yong)(yong)量(liang)約(yue)達(da)2.0萬t。根據觀研(yan)天下(xia)的新研(yan)究,增(zeng)加有(you)機硅材料在汽(qi)車(che)(che)(che)零部(bu)件方面的用(yong)(yong)量(liang),可以大(da)幅度提高(gao)汽(qi)車(che)(che)(che)的安全性能,因此(ci),汽(qi)車(che)(che)(che)產量(liang)和單車(che)(che)(che)用(yong)(yong)量(liang)水平(ping)的提高(gao)都(dou)將(jiang)推(tui)動汽(qi)車(che)(che)(che)工(gong)(gong)業(ye)對(dui)硅橡膠需求的增(zeng)加。國家(jia)鼓勵自主品(pin)牌的汽(qi)車(che)(che)(che)發(fa)展,關(guan)鍵汽(qi)車(che)(che)(che)零部(bu)件實現自主化(hua),《2012年(nian)度黨(dang)政機關(guan)公(gong)務用(yong)(yong)車(che)(che)(che)選(xuan)用(yong)(yong)車(che)(che)(che)型目錄(征求意(yi)見(jian)稿)》為(wei)自主品(pin)牌擴大(da)在政府采購(gou)的市場份額,為(wei)改變目前(qian)國內政府采購(gou)以合資(zi)品(pin)牌產品(pin)為(wei)主的局面提供了保障(zhang)。促進自主品(pin)牌發(fa)展,國產汽(qi)車(che)(che)(che)業(ye)的繁榮(rong)將(jiang)為(wei)汽(qi)車(che)(che)(che)膠的應用(yong)(yong)提供有(you)力保障(zhang)。預測未來3年(nian),我國室(shi)溫(wen)硫化(hua)硅橡膠在汽(qi)車(che)(che)(che)行業(ye)將(jiang)以年(nian)均20%增(zeng)長(chang)。
此(ci)外(wai),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠是(shi)重要的(de)(de)非(fei)石(shi)油(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)(xiang)膠,約占非(fei)石(shi)油(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)(xiang)膠消費量的(de)(de)98%。但因(yin)為石(shi)油(you)價格的(de)(de)大(da)(da)幅上漲,同(tong)(tong)時我國(guo)(guo)在硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)關鍵原料有機硅(gui)(gui)單體(ti)的(de)(de)生(sheng)產技術方面(mian)取得突破,有機硅(gui)(gui)單體(ti)的(de)(de)生(sheng)產技術在2005年前被幾家跨國(guo)(guo)公司壟斷,但目前我國(guo)(guo)已發(fa)展成(cheng)為全(quan)球有機硅(gui)(gui)單體(ti)第1大(da)(da)國(guo)(guo),這2個方面(mian)原因(yin)使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)價格從2011年起開始低于石(shi)油(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)(xiang)膠,僅(jin)約為大(da)(da)宗石(shi)油(you)基(ji)(ji)橡(xiang)(xiang)(xiang)膠的(de)(de)80%~90%,成(cheng)為廉價的(de)(de)合(he)成(cheng)橡(xiang)(xiang)(xiang)膠,并(bing)開始大(da)(da)規(gui)模替代(dai)石(shi)油(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)(xiang)膠。這將極(ji)大(da)(da)拓展有機硅(gui)(gui)產業的(de)(de)市場空間,同(tong)(tong)時將帶動硅(gui)(gui)油(you)、硅(gui)(gui)烷(wan)偶聯(lian)劑和(he)硅(gui)(gui)樹脂等其他有機硅(gui)(gui)產品的(de)(de)消費。