硅橡膠是指主鏈由(you)硅(gui)和氧(yang)原子(zi)交替構成(cheng),硅(gui)原子(zi)上通常(chang)連有(you)兩個(ge)有(you)機(ji)基團(tuan)的橡(xiang)膠(jiao)。普通的硅(gui)橡(xiang)膠(jiao)主要由(you)含甲基和少量乙烯基的硅(gui)氧(yang)鏈節組成(cheng)。苯基的引(yin)入(ru)可提(ti)高硅(gui)橡(xiang)膠(jiao)的耐高、低溫性(xing)(xing)能(neng),三氟丙(bing)基及氰基的引(yin)入(ru)則可提(ti)高硅(gui)橡(xiang)膠(jiao)的耐溫及耐油(you)性(xing)(xing)能(neng)。硅(gui)橡(xiang)膠(jiao)耐低溫性(xing)(xing)能(neng)良好(hao)(hao),一般在(zai)-55℃下仍能(neng)工作(zuo)。引(yin)入(ru)苯基后(hou),可達-73℃。硅(gui)橡(xiang)膠(jiao)的耐熱(re)性(xing)(xing)能(neng)也很突出,在(zai)180℃下可長期工作(zuo),稍高于200℃也能(neng)承受數周或(huo)更長時(shi)間仍有(you)彈性(xing)(xing),瞬時(shi)可耐300℃以(yi)上的高溫。硅(gui)橡(xiang)膠(jiao)的透氣性(xing)(xing)好(hao)(hao),氧(yang)氣透過率在(zai)合成(cheng)聚(ju)合物(wu)中是較高的。此外,硅(gui)橡(xiang)膠(jiao)還具有(you)生(sheng)理(li)惰(duo)性(xing)(xing)、不會(hui)導致凝血的突出特性(xing)(xing),因此在(zai)醫用領域應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)分(fen)類的(de)(de)方法很多,通(tong)常(chang)按固化(hua)前的(de)(de)形態(tai)分(fen)為固體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)和(he)液(ye)體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao);按硫(liu)(liu)化(hua)溫度分(fen)為室溫硫(liu)(liu)化(hua)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao),高(gao)(gao)溫硫(liu)(liu)化(hua)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao);按所(suo)用(yong)單體的(de)(de)不同(tong),可分(fen)為甲基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)、氟(fu)硅(gui),腈硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)等(deng);按性能和(he)用(yong)途的(de)(de)不同(tong)又可分(fen)為通(tong)用(yong)型(xing)(xing)(xing)、超耐(nai)低溫型(xing)(xing)(xing)、超耐(nai)高(gao)(gao)溫型(xing)(xing)(xing)、高(gao)(gao)強力型(xing)(xing)(xing)、耐(nai)油型(xing)(xing)(xing)、醫用(yong)型(xing)(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)橡膠(jiao)早期是由美國(guo)(guo)(guo)以三氯(lv)化(hua)鐵為(wei)催化(hua)劑(ji)合(he)成(cheng)的(de)(de)(de)。1945年(nian),硅(gui)(gui)橡膠(jiao)產(chan)(chan)品問世。1948年(nian),采(cai)用(yong)(yong)高比表面(mian)積的(de)(de)(de)氣相法(fa)白炭黑補強的(de)(de)(de)硅(gui)(gui)橡膠(jiao)研制成(cheng)功,使(shi)硅(gui)(gui)橡膠(jiao)的(de)(de)(de)性能躍(yue)升到實用(yong)(yong)階段,奠(dian)定了現代硅(gui)(gui)橡膠(jiao)生產(chan)(chan)技術的(de)(de)(de)基(ji)礎。從二甲基(ji)二氯(lv)硅(gui)(gui)烷合(he)成(cheng)開(kai)(kai)始生產(chan)(chan)硅(gui)(gui)橡膠(jiao)的(de)(de)(de)國(guo)(guo)(guo)家有美國(guo)(guo)(guo)。俄羅斯、德(de)國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)(zhong)國(guo)(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)橡膠(jiao)的(de)(de)(de)工業化(hua)研究(jiu)始于(yu)1957年(nian),多家研究(jiu)所和企業陸續開(kai)(kai)發(fa)出各種硅(gui)(gui)橡膠(jiao)。到2003年(nian)底,中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)橡膠(jiao)生產(chan)(chan)能力為(wei)135千(qian)噸(dun),其(qi)中(zhong)(zhong)高溫膠(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)硅橡膠(jiao)(jiao)是(shi)指聚硅氧(yang)烷變成(cheng)彈性(xing)體的(de)過程是(shi)經過高(gao)溫(110-170℃)硫(liu)化(hua)成(cheng)型的(de)。它主(zhu)要以高(gao)分(fen)子量的(de)聚甲基(ji)乙烯(xi)基(ji)硅氧(yang)烷為生膠(jiao)(jiao),混入補強填料(liao)、硫(liu)化(hua)劑等,在加(jia)熱(re)加(jia)壓(ya)下硫(liu)化(hua)成(cheng)彈性(xing)體。硅橡膠(jiao)(jiao)的(de)補強主(zhu)要是(shi)各(ge)種類型的(de)白(bai)炭(tan)黑,可使硫(liu)化(hua)膠(jiao)(jiao)的(de)強度增加(jia)數(shu)十(shi)倍。有時為了(le)降低成(cheng)本或(huo)改善(shan)膠(jiao)(jiao)料(liao)性(xing)能及賦予硫(liu)化(hua)膠(jiao)(jiao)各(ge)種特殊的(de)性(xing)能,也加(jia)入相應的(de)各(ge)種添加(jia)劑。硫(liu)化(hua)劑是(shi)各(ge)種有機過氧(yang)化(hua)物(wu)或(huo)加(jia)成(cheng)反應催化(hua)劑。
加工成型(xing)方(fang)法如圖所(suo)示(shi)。一次(ci)硫化的目的是(shi)進行高(gao)分子鏈的交聯反應;二次(ci)硫化的目的是(shi)進行補充交聯、驅除(chu)硫化劑分解產物和其他揮發性化合物以穩(wen)定硫化膠的各項(xiang)性能(neng)。常用的設備(bei)有開放式煉膠機、捏合機及真(zhen)空密煉機。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)(de)特征是(shi)高(gao)溫(wen)穩(wen)(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常溫(wen)下(xia)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅是(shi)天然(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一半,但在(zai)200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)環境(jing)下(xia),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)保(bao)持一定(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明(ming)顯(xian)變化(hua)。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化(hua)溫(wen)度(du)一般為-70~-50℃,特殊配方(fang)可達-100℃,表(biao)明(ming)其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對(dui)航空、宇航工(gong)業的(de)(de)(de)(de)(de)意義重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)氧(yang)、臭(chou)氧(yang)及(ji)紫(zi)外線(xian)等(deng)十分穩(wen)(wen)定(ding),在(zai)不(bu)加(jia)任何添加(jia)劑的(de)(de)(de)(de)(de)情況(kuang)下(xia),就具有(you)優良(liang)的(de)(de)(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具有(you)優異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好(hao)。(5)物(wu)(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)常溫(wen)下(xia)的(de)(de)(de)(de)(de)物(wu)(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)和-50℃的(de)(de)(de)(de)(de)低溫(wen)下(xia),其物(wu)(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通用橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐油及(ji)化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具有(you)中等(deng)的(de)(de)(de)(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)下(xia)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣、氮、氧(yang)、二(er)氧(yang)化(hua)碳等(deng)氣體(ti)(ti)的(de)(de)(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)(ti)組織不(bu)粘連(lian),具有(you)抗凝(ning)血作用,對(dui)肌體(ti)(ti)組織的(de)(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特別適合(he)作為醫(yi)用材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)(ye)(ye)協會統計,2012年(nian)(nian)(nian),汽(qi)(qi)(qi)車(che)(che)(che)(che)產銷分別達(da)到1927.18萬輛(liang)和(he)1930.64萬輛(liang),同比(bi)分別增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)(ye)(ye)硅橡膠(jiao)(jiao)(jiao)的(de)用(yong)(yong)量(liang)約(yue)達(da)2.0萬t。根據觀研天(tian)下的(de)新研究,增(zeng)加有機硅材料在汽(qi)(qi)(qi)車(che)(che)(che)(che)零部(bu)件(jian)方面的(de)用(yong)(yong)量(liang),可(ke)以(yi)大(da)幅度提高汽(qi)(qi)(qi)車(che)(che)(che)(che)的(de)安全性能,因此(ci),汽(qi)(qi)(qi)車(che)(che)(che)(che)產量(liang)和(he)單車(che)(che)(che)(che)用(yong)(yong)量(liang)水(shui)平的(de)提高都將(jiang)推(tui)動汽(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)(ye)(ye)對硅橡膠(jiao)(jiao)(jiao)需求的(de)增(zeng)加。國家(jia)鼓(gu)勵自(zi)主(zhu)品牌的(de)汽(qi)(qi)(qi)車(che)(che)(che)(che)發(fa)展,關鍵(jian)汽(qi)(qi)(qi)車(che)(che)(che)(che)零部(bu)件(jian)實現自(zi)主(zhu)化,《2012年(nian)(nian)(nian)度黨政(zheng)(zheng)機關公務用(yong)(yong)車(che)(che)(che)(che)選用(yong)(yong)車(che)(che)(che)(che)型目(mu)錄(征求意見(jian)稿(gao))》為(wei)自(zi)主(zhu)品牌擴(kuo)大(da)在政(zheng)(zheng)府采購(gou)的(de)市(shi)場份額(e),為(wei)改變(bian)目(mu)前國內政(zheng)(zheng)府采購(gou)以(yi)合資(zi)品牌產品為(wei)主(zhu)的(de)局面提供了(le)保(bao)障。促進自(zi)主(zhu)品牌發(fa)展,國產汽(qi)(qi)(qi)車(che)(che)(che)(che)業(ye)(ye)(ye)(ye)的(de)繁榮將(jiang)為(wei)汽(qi)(qi)(qi)車(che)(che)(che)(che)膠(jiao)(jiao)(jiao)的(de)應(ying)用(yong)(yong)提供有力保(bao)障。預測未來(lai)3年(nian)(nian)(nian),我國室溫(wen)硫化硅橡膠(jiao)(jiao)(jiao)在汽(qi)(qi)(qi)車(che)(che)(che)(che)行業(ye)(ye)(ye)(ye)將(jiang)以(yi)年(nian)(nian)(nian)均20%增(zeng)長。
此外,硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重要(yao)的(de)(de)(de)(de)非石(shi)(shi)油(you)(you)基(ji)合成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)(you)基(ji)合成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消(xiao)費(fei)量的(de)(de)(de)(de)98%。但(dan)因為石(shi)(shi)油(you)(you)價格的(de)(de)(de)(de)大(da)幅(fu)上漲,同(tong)時(shi)我國(guo)在(zai)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)關(guan)鍵原(yuan)料有機(ji)(ji)(ji)硅(gui)單體的(de)(de)(de)(de)生產(chan)(chan)技(ji)術方面取得(de)突破(po),有機(ji)(ji)(ji)硅(gui)單體的(de)(de)(de)(de)生產(chan)(chan)技(ji)術在(zai)2005年前被幾家跨(kua)國(guo)公司壟斷(duan),但(dan)目(mu)前我國(guo)已發(fa)展成(cheng)(cheng)(cheng)為全球有機(ji)(ji)(ji)硅(gui)單體第1大(da)國(guo),這2個方面原(yuan)因使(shi)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)價格從2011年起開始低于(yu)石(shi)(shi)油(you)(you)基(ji)合成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅(jin)約為大(da)宗石(shi)(shi)油(you)(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)80%~90%,成(cheng)(cheng)(cheng)為廉價的(de)(de)(de)(de)合成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始大(da)規模替(ti)代石(shi)(shi)油(you)(you)基(ji)合成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)拓(tuo)展有機(ji)(ji)(ji)硅(gui)產(chan)(chan)業的(de)(de)(de)(de)市(shi)場空間,同(tong)時(shi)將帶動硅(gui)油(you)(you)、硅(gui)烷(wan)偶聯(lian)劑和硅(gui)樹脂等其他有機(ji)(ji)(ji)硅(gui)產(chan)(chan)品(pin)的(de)(de)(de)(de)消(xiao)費(fei)。