硅橡膠是(shi)指主鏈(lian)由硅(gui)和(he)氧(yang)原子(zi)交替構成,硅(gui)原子(zi)上(shang)通(tong)常連(lian)有兩個(ge)有機基(ji)(ji)(ji)團的(de)(de)橡膠(jiao)(jiao)。普通(tong)的(de)(de)硅(gui)橡膠(jiao)(jiao)主要由含甲基(ji)(ji)(ji)和(he)少(shao)量乙烯基(ji)(ji)(ji)的(de)(de)硅(gui)氧(yang)鏈(lian)節組成。苯(ben)基(ji)(ji)(ji)的(de)(de)引(yin)(yin)入可(ke)提高硅(gui)橡膠(jiao)(jiao)的(de)(de)耐(nai)高、低溫性能(neng)(neng),三氟丙(bing)基(ji)(ji)(ji)及(ji)氰基(ji)(ji)(ji)的(de)(de)引(yin)(yin)入則(ze)可(ke)提高硅(gui)橡膠(jiao)(jiao)的(de)(de)耐(nai)溫及(ji)耐(nai)油性能(neng)(neng)。硅(gui)橡膠(jiao)(jiao)耐(nai)低溫性能(neng)(neng)良(liang)好(hao),一般在-55℃下仍能(neng)(neng)工作。引(yin)(yin)入苯(ben)基(ji)(ji)(ji)后,可(ke)達-73℃。硅(gui)橡膠(jiao)(jiao)的(de)(de)耐(nai)熱性能(neng)(neng)也很突出(chu),在180℃下可(ke)長期工作,稍高于200℃也能(neng)(neng)承(cheng)受(shou)數周或更長時(shi)間仍有彈性,瞬時(shi)可(ke)耐(nai)300℃以上(shang)的(de)(de)高溫。硅(gui)橡膠(jiao)(jiao)的(de)(de)透(tou)氣(qi)性好(hao),氧(yang)氣(qi)透(tou)過率在合(he)成聚合(he)物(wu)中是(shi)較(jiao)高的(de)(de)。此外,硅(gui)橡膠(jiao)(jiao)還(huan)具有生理惰性、不(bu)會導致凝血(xue)的(de)(de)突出(chu)特性,因(yin)此在醫用(yong)領(ling)域應用(yong)廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分(fen)類的方(fang)法很多,通(tong)常按(an)(an)固(gu)化(hua)前的形態分(fen)為(wei)(wei)固(gu)體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)硫(liu)化(hua)溫(wen)(wen)度分(fen)為(wei)(wei)室溫(wen)(wen)硫(liu)化(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高溫(wen)(wen)硫(liu)化(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)所用單體的不同,可分(fen)為(wei)(wei)甲基乙(yi)烯基硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基苯基乙(yi)烯基硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈(jing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)(an)性(xing)能(neng)和用途的不同又可分(fen)為(wei)(wei)通(tong)用型(xing)(xing)、超耐(nai)(nai)低溫(wen)(wen)型(xing)(xing)、超耐(nai)(nai)高溫(wen)(wen)型(xing)(xing)、高強力(li)型(xing)(xing)、耐(nai)(nai)油型(xing)(xing)、醫用型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)早(zao)期(qi)是由美(mei)國(guo)(guo)以(yi)三(san)氯化(hua)鐵為(wei)催化(hua)劑(ji)合成的。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)產品問世。1948年(nian),采用高(gao)(gao)比表面積的氣相法白炭黑補強的硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)研(yan)(yan)(yan)制成功,使硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的性能(neng)躍升到實用階段(duan),奠定(ding)了現代硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產技(ji)術的基(ji)礎。從二甲基(ji)二氯硅(gui)(gui)(gui)烷合成開(kai)始生產硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的國(guo)(guo)家(jia)有美(mei)國(guo)(guo)。俄羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的工業化(hua)研(yan)(yan)(yan)究始于1957年(nian),多家(jia)研(yan)(yan)(yan)究所和企(qi)業陸續開(kai)發出各種硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產能(neng)力為(wei)135千噸(dun),其中(zhong)高(gao)(gao)溫膠(jiao)(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)是指聚硅(gui)(gui)氧烷變成(cheng)彈性(xing)體的(de)(de)(de)(de)過程是經過高溫(110-170℃)硫(liu)化(hua)成(cheng)型的(de)(de)(de)(de)。它(ta)主(zhu)要(yao)以(yi)高分子量的(de)(de)(de)(de)聚甲基乙(yi)烯基硅(gui)(gui)氧烷為生(sheng)膠(jiao),混入(ru)補強(qiang)填料、硫(liu)化(hua)劑(ji)等(deng),在(zai)加(jia)(jia)熱加(jia)(jia)壓(ya)下硫(liu)化(hua)成(cheng)彈性(xing)體。硅(gui)(gui)橡膠(jiao)的(de)(de)(de)(de)補強(qiang)主(zhu)要(yao)是各種類型的(de)(de)(de)(de)白炭黑,可使(shi)硫(liu)化(hua)膠(jiao)的(de)(de)(de)(de)強(qiang)度增加(jia)(jia)數十倍。有時為了降低(di)成(cheng)本或改(gai)善膠(jiao)料性(xing)能及賦予硫(liu)化(hua)膠(jiao)各種特殊的(de)(de)(de)(de)性(xing)能,也加(jia)(jia)入(ru)相(xiang)應的(de)(de)(de)(de)各種添加(jia)(jia)劑(ji)。硫(liu)化(hua)劑(ji)是各種有機過氧化(hua)物或加(jia)(jia)成(cheng)反應催化(hua)劑(ji)。
加工成(cheng)型方法(fa)如圖所示。一次硫化(hua)(hua)的(de)(de)目的(de)(de)是進行(xing)高分子鏈的(de)(de)交聯(lian)(lian)反(fan)應;二次硫化(hua)(hua)的(de)(de)目的(de)(de)是進行(xing)補充交聯(lian)(lian)、驅除硫化(hua)(hua)劑分解產物和其他揮發性化(hua)(hua)合(he)物以穩定硫化(hua)(hua)膠的(de)(de)各項性能(neng)。常用的(de)(de)設備有開放式煉(lian)膠機(ji)、捏合(he)機(ji)及(ji)真空(kong)密煉(lian)機(ji)。
主要性能
(1)高(gao)(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠顯著的(de)(de)(de)(de)(de)特征是高(gao)(gao)溫(wen)(wen)穩(wen)定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)(de)強度僅(jin)是天然(ran)橡(xiang)(xiang)(xiang)膠或某些合成(cheng)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)(de)一半,但在200℃以上(shang)的(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)環境下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠仍(reng)能(neng)(neng)(neng)保持一定(ding)(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬(ying)度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明(ming)(ming)顯變化。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)度一般(ban)為-70~-50℃,特殊配方可達-100℃,表(biao)明(ming)(ming)其(qi)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異(yi)。這(zhe)對(dui)航空(kong)、宇(yu)航工業(ye)的(de)(de)(de)(de)(de)意義(yi)重大(da)。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠中Si-O-Si鍵對(dui)氧、臭氧及紫外線等(deng)十分穩(wen)定(ding)(ding),在不加任(ren)何(he)添加劑(ji)的(de)(de)(de)(de)(de)情況下(xia),就具(ju)有(you)優良的(de)(de)(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠具(ju)有(you)優異(yi)的(de)(de)(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠常(chang)(chang)溫(wen)(wen)下(xia)的(de)(de)(de)(de)(de)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠差,但在150℃的(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)和-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)下(xia),其(qi)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠。(6)耐油(you)及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠具(ju)有(you)中等(deng)的(de)(de)(de)(de)(de)耐油(you)、耐溶劑(ji)性(xing)(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)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠對(dui)空(kong)氣、氮、氧、二氧化碳等(deng)氣體(ti)的(de)(de)(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)膠高(gao)(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人體(ti)組織(zhi)不粘連,具(ju)有(you)抗凝血作(zuo)用(yong)(yong),對(dui)肌體(ti)組織(zhi)的(de)(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特別適合作(zuo)為醫用(yong)(yong)材(cai)料。
硅橡膠的用量
據中(zhong)國(guo)汽(qi)(qi)車(che)(che)(che)工業(ye)協(xie)會統計(ji),2012年(nian)(nian),汽(qi)(qi)車(che)(che)(che)產(chan)(chan)(chan)銷分別達(da)到1927.18萬(wan)(wan)輛(liang)和(he)1930.64萬(wan)(wan)輛(liang),同比(bi)分別增(zeng)(zeng)長4.63%和(he)4.33%,汽(qi)(qi)車(che)(che)(che)工業(ye)硅(gui)橡(xiang)膠(jiao)的用(yong)量(liang)約達(da)2.0萬(wan)(wan)t。根據觀研天下的新研究,增(zeng)(zeng)加有機硅(gui)材料在(zai)汽(qi)(qi)車(che)(che)(che)零部(bu)件(jian)方面的用(yong)量(liang),可以(yi)大幅(fu)度提高(gao)汽(qi)(qi)車(che)(che)(che)的安全性能(neng),因此,汽(qi)(qi)車(che)(che)(che)產(chan)(chan)(chan)量(liang)和(he)單車(che)(che)(che)用(yong)量(liang)水平的提高(gao)都將(jiang)推(tui)動(dong)汽(qi)(qi)車(che)(che)(che)工業(ye)對硅(gui)橡(xiang)膠(jiao)需求的增(zeng)(zeng)加。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)的汽(qi)(qi)車(che)(che)(che)發(fa)(fa)展,關(guan)鍵汽(qi)(qi)車(che)(che)(che)零部(bu)件(jian)實現自(zi)主(zhu)化(hua),《2012年(nian)(nian)度黨(dang)政(zheng)(zheng)機關(guan)公務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目錄(lu)(征求意見稿(gao))》為(wei)自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)擴大在(zai)政(zheng)(zheng)府(fu)采(cai)購的市場份(fen)額,為(wei)改變目前國(guo)內政(zheng)(zheng)府(fu)采(cai)購以(yi)合資品(pin)(pin)(pin)牌(pai)產(chan)(chan)(chan)品(pin)(pin)(pin)為(wei)主(zhu)的局面提供(gong)了保(bao)障(zhang)。促進自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)發(fa)(fa)展,國(guo)產(chan)(chan)(chan)汽(qi)(qi)車(che)(che)(che)業(ye)的繁(fan)榮(rong)將(jiang)為(wei)汽(qi)(qi)車(che)(che)(che)膠(jiao)的應用(yong)提供(gong)有力(li)保(bao)障(zhang)。預測未來3年(nian)(nian),我國(guo)室溫(wen)硫化(hua)硅(gui)橡(xiang)膠(jiao)在(zai)汽(qi)(qi)車(che)(che)(che)行業(ye)將(jiang)以(yi)年(nian)(nian)均(jun)20%增(zeng)(zeng)長。
此(ci)外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重要的(de)(de)非石(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消費量的(de)(de)98%。但(dan)因(yin)為石(shi)油價(jia)格的(de)(de)大(da)(da)(da)幅上漲,同(tong)(tong)時(shi)(shi)我國(guo)(guo)在硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關鍵原料有(you)機(ji)硅(gui)(gui)(gui)單體的(de)(de)生(sheng)產(chan)(chan)技術方面取得突(tu)破,有(you)機(ji)硅(gui)(gui)(gui)單體的(de)(de)生(sheng)產(chan)(chan)技術在2005年前被幾家(jia)跨(kua)國(guo)(guo)公司(si)壟(long)斷(duan),但(dan)目前我國(guo)(guo)已(yi)發展(zhan)成(cheng)為全(quan)球有(you)機(ji)硅(gui)(gui)(gui)單體第1大(da)(da)(da)國(guo)(guo),這(zhe)2個方面原因(yin)使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價(jia)格從2011年起開始低于(yu)石(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅約為大(da)(da)(da)宗石(shi)油基(ji)(ji)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為廉價(jia)的(de)(de)合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并開始大(da)(da)(da)規模(mo)替代石(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將(jiang)極(ji)大(da)(da)(da)拓展(zhan)有(you)機(ji)硅(gui)(gui)(gui)產(chan)(chan)業的(de)(de)市場空間,同(tong)(tong)時(shi)(shi)將(jiang)帶(dai)動(dong)硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹(shu)脂等其(qi)他有(you)機(ji)硅(gui)(gui)(gui)產(chan)(chan)品的(de)(de)消費。