硅橡膠是(shi)指主鏈由硅(gui)(gui)(gui)和氧原子交替構成(cheng)(cheng),硅(gui)(gui)(gui)原子上(shang)通常連有(you)兩個(ge)有(you)機(ji)基(ji)團的(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)。普通的(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)主要(yao)由含甲(jia)基(ji)和少量(liang)乙烯(xi)基(ji)的(de)(de)硅(gui)(gui)(gui)氧鏈節組成(cheng)(cheng)。苯(ben)基(ji)的(de)(de)引入可(ke)(ke)提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)高(gao)(gao)、低(di)溫(wen)性(xing)(xing)(xing)能(neng),三氟丙(bing)基(ji)及氰基(ji)的(de)(de)引入則可(ke)(ke)提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)耐(nai)(nai)低(di)溫(wen)性(xing)(xing)(xing)能(neng)良好,一般在-55℃下仍能(neng)工(gong)(gong)作。引入苯(ben)基(ji)后(hou),可(ke)(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)熱性(xing)(xing)(xing)能(neng)也很(hen)突(tu)出,在180℃下可(ke)(ke)長(chang)期(qi)工(gong)(gong)作,稍高(gao)(gao)于200℃也能(neng)承(cheng)受(shou)數周或(huo)更(geng)長(chang)時(shi)間仍有(you)彈性(xing)(xing)(xing),瞬時(shi)可(ke)(ke)耐(nai)(nai)300℃以上(shang)的(de)(de)高(gao)(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)透氣性(xing)(xing)(xing)好,氧氣透過率在合成(cheng)(cheng)聚合物(wu)中是(shi)較(jiao)高(gao)(gao)的(de)(de)。此(ci)外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)還具有(you)生理(li)惰性(xing)(xing)(xing)、不會導(dao)致凝(ning)血(xue)的(de)(de)突(tu)出特性(xing)(xing)(xing),因此(ci)在醫用領域應(ying)用廣(guang)泛。
主要品種
硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分類的方法很多(duo),通(tong)常按固化前的形態(tai)分為(wei)固體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和(he)液體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按硫(liu)化溫(wen)度分為(wei)室(shi)溫(wen)硫(liu)化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫(liu)化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按所用(yong)單體的不(bu)同,可分為(wei)甲(jia)基乙(yi)烯基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲(jia)基苯基乙(yi)烯基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等;按性能和(he)用(yong)途的不(bu)同又可分為(wei)通(tong)用(yong)型、超耐(nai)低溫(wen)型、超耐(nai)高(gao)溫(wen)型、高(gao)強力(li)型、耐(nai)油(you)型、醫用(yong)型等等。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期是由美(mei)國以(yi)三氯化(hua)鐵為催化(hua)劑合成(cheng)的(de)。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品問(wen)世。1948年(nian),采用(yong)高比表(biao)面(mian)積的(de)氣相法白炭黑補強的(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)研制成(cheng)功,使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)性能(neng)躍升到實用(yong)階段(duan),奠(dian)定了(le)現代硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)技術的(de)基礎。從二(er)甲基二(er)氯硅(gui)(gui)(gui)烷(wan)合成(cheng)開始生(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)國家有美(mei)國。俄羅斯(si)、德國、日本、韓國和中(zhong)國等。中(zhong)國硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)工(gong)業化(hua)研究(jiu)始于1957年(nian),多家研究(jiu)所和企業陸(lu)續開發出各種硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底,中(zhong)國硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)能(neng)力為135千(qian)噸,其中(zhong)高溫(wen)膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)(liu)化(hua)硅橡膠(jiao)是(shi)(shi)指(zhi)聚硅氧烷變成(cheng)彈性(xing)體(ti)的過(guo)程是(shi)(shi)經(jing)過(guo)高(gao)溫(110-170℃)硫(liu)(liu)(liu)化(hua)成(cheng)型的。它主要以高(gao)分子量(liang)的聚甲基乙烯基硅氧烷為(wei)生膠(jiao),混入補(bu)強(qiang)填料、硫(liu)(liu)(liu)化(hua)劑等,在加熱(re)加壓(ya)下硫(liu)(liu)(liu)化(hua)成(cheng)彈性(xing)體(ti)。硅橡膠(jiao)的補(bu)強(qiang)主要是(shi)(shi)各(ge)(ge)(ge)(ge)種(zhong)(zhong)類型的白炭黑,可使硫(liu)(liu)(liu)化(hua)膠(jiao)的強(qiang)度增加數(shu)十倍。有(you)時為(wei)了降(jiang)低(di)成(cheng)本或改善膠(jiao)料性(xing)能及賦予硫(liu)(liu)(liu)化(hua)膠(jiao)各(ge)(ge)(ge)(ge)種(zhong)(zhong)特殊的性(xing)能,也加入相(xiang)應的各(ge)(ge)(ge)(ge)種(zhong)(zhong)添加劑。硫(liu)(liu)(liu)化(hua)劑是(shi)(shi)各(ge)(ge)(ge)(ge)種(zhong)(zhong)有(you)機過(guo)氧化(hua)物或加成(cheng)反應催化(hua)劑。
加工成型方(fang)法如圖所示。一次硫(liu)(liu)化(hua)的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)是(shi)進(jin)(jin)行高分子鏈的(de)(de)(de)(de)交聯反應;二次硫(liu)(liu)化(hua)的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)是(shi)進(jin)(jin)行補充交聯、驅除硫(liu)(liu)化(hua)劑分解(jie)產物和其(qi)他揮(hui)發性化(hua)合(he)物以穩定硫(liu)(liu)化(hua)膠的(de)(de)(de)(de)各項性能。常(chang)用的(de)(de)(de)(de)設備有開放式煉膠機、捏(nie)合(he)機及真空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯著的(de)特(te)征是(shi)高(gao)溫(wen)(wen)穩(wen)(wen)定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)強(qiang)度(du)僅是(shi)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)一(yi)半,但在200℃以上的(de)高(gao)溫(wen)(wen)環境(jing)下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)保持一(yi)定(ding)(ding)的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度(du),且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明(ming)顯變化(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)玻璃化(hua)溫(wen)(wen)度(du)一(yi)般為-70~-50℃,特(te)殊(shu)配方可達(da)-100℃,表(biao)明(ming)其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異。這對航空(kong)、宇航工業(ye)的(de)意義(yi)重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭(chou)氧(yang)及紫外(wai)線(xian)等(deng)十分穩(wen)(wen)定(ding)(ding),在不(bu)加任何添加劑的(de)情況下(xia),就具(ju)有(you)(you)優良的(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)優異的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)電暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常(chang)好。(5)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)下(xia)的(de)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比(bi)通用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差(cha),但在150℃的(de)高(gao)溫(wen)(wen)和(he)-50℃的(de)低溫(wen)(wen)下(xia),其物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)中等(deng)的(de)耐(nai)(nai)油、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣體(ti)(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對空(kong)氣、氮、氧(yang)、二氧(yang)化(hua)碳等(deng)氣體(ti)(ti)的(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生(sheng)理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(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,具(ju)有(you)(you)抗(kang)凝血作用,對肌(ji)體(ti)(ti)組織的(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少(shao)。特(te)別(bie)適合作為醫用材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業協會統計,2012年,汽(qi)(qi)(qi)車(che)(che)(che)產(chan)銷分(fen)別達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分(fen)別增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業硅橡(xiang)膠(jiao)的(de)用(yong)(yong)量(liang)(liang)約達2.0萬t。根據觀研天(tian)下的(de)新研究,增(zeng)加有機(ji)硅材料在(zai)汽(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)方面(mian)的(de)用(yong)(yong)量(liang)(liang),可以(yi)大幅度提(ti)高汽(qi)(qi)(qi)車(che)(che)(che)的(de)安全(quan)性(xing)能,因此,汽(qi)(qi)(qi)車(che)(che)(che)產(chan)量(liang)(liang)和單車(che)(che)(che)用(yong)(yong)量(liang)(liang)水(shui)平的(de)提(ti)高都將(jiang)(jiang)推動(dong)汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業對硅橡(xiang)膠(jiao)需(xu)求的(de)增(zeng)加。國(guo)(guo)家鼓(gu)勵(li)自(zi)主(zhu)(zhu)品牌的(de)汽(qi)(qi)(qi)車(che)(che)(che)發展,關鍵汽(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)實現(xian)自(zi)主(zhu)(zhu)化(hua),《2012年度黨政(zheng)機(ji)關公務(wu)用(yong)(yong)車(che)(che)(che)選用(yong)(yong)車(che)(che)(che)型(xing)目(mu)錄(lu)(征(zheng)求意見稿(gao))》為(wei)(wei)(wei)自(zi)主(zhu)(zhu)品牌擴大在(zai)政(zheng)府(fu)采購(gou)的(de)市場份額,為(wei)(wei)(wei)改(gai)變目(mu)前(qian)國(guo)(guo)內政(zheng)府(fu)采購(gou)以(yi)合資品牌產(chan)品為(wei)(wei)(wei)主(zhu)(zhu)的(de)局面(mian)提(ti)供(gong)了保(bao)障。促進自(zi)主(zhu)(zhu)品牌發展,國(guo)(guo)產(chan)汽(qi)(qi)(qi)車(che)(che)(che)業的(de)繁榮將(jiang)(jiang)為(wei)(wei)(wei)汽(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的(de)應(ying)用(yong)(yong)提(ti)供(gong)有力保(bao)障。預測未來3年,我國(guo)(guo)室溫硫化(hua)硅橡(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)車(che)(che)(che)行業將(jiang)(jiang)以(yi)年均20%增(zeng)長。
此(ci)外(wai),硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的(de)非石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠,約(yue)(yue)占非石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠消費(fei)量的(de)98%。但(dan)(dan)因(yin)為(wei)石(shi)油(you)(you)價(jia)格的(de)大(da)幅上(shang)漲,同(tong)時(shi)我國(guo)在硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)關鍵原(yuan)料有機硅(gui)(gui)(gui)(gui)單體的(de)生(sheng)產技術方面(mian)取得突(tu)破,有機硅(gui)(gui)(gui)(gui)單體的(de)生(sheng)產技術在2005年前被幾家跨國(guo)公司壟斷,但(dan)(dan)目前我國(guo)已(yi)發展成(cheng)(cheng)為(wei)全球有機硅(gui)(gui)(gui)(gui)單體第1大(da)國(guo),這(zhe)2個方面(mian)原(yuan)因(yin)使硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)價(jia)格從(cong)2011年起開(kai)始(shi)低于(yu)石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠,僅約(yue)(yue)為(wei)大(da)宗石(shi)油(you)(you)基(ji)橡(xiang)(xiang)膠的(de)80%~90%,成(cheng)(cheng)為(wei)廉價(jia)的(de)合成(cheng)(cheng)橡(xiang)(xiang)膠,并開(kai)始(shi)大(da)規模(mo)替代石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠。這(zhe)將(jiang)極大(da)拓展有機硅(gui)(gui)(gui)(gui)產業的(de)市場空間,同(tong)時(shi)將(jiang)帶動硅(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)(gui)樹脂等其他有機硅(gui)(gui)(gui)(gui)產品的(de)消費(fei)。