
硅橡膠是指(zhi)主(zhu)鏈由硅(gui)(gui)和氧原(yuan)子(zi)交(jiao)替構成(cheng),硅(gui)(gui)原(yuan)子(zi)上通常連有兩個有機基(ji)團的(de)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。普通的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)主(zhu)要由含(han)甲基(ji)和少(shao)量乙烯(xi)基(ji)的(de)硅(gui)(gui)氧鏈節組成(cheng)。苯基(ji)的(de)引入可(ke)(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)高(gao)(gao)(gao)、低(di)溫(wen)性能(neng)(neng)(neng),三(san)氟(fu)丙(bing)基(ji)及(ji)氰基(ji)的(de)引入則可(ke)(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)溫(wen)及(ji)耐(nai)(nai)油性能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)耐(nai)(nai)低(di)溫(wen)性能(neng)(neng)(neng)良好,一般在(zai)-55℃下仍能(neng)(neng)(neng)工(gong)作。引入苯基(ji)后,可(ke)(ke)達(da)-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)熱性能(neng)(neng)(neng)也(ye)很突出,在(zai)180℃下可(ke)(ke)長(chang)期(qi)工(gong)作,稍高(gao)(gao)(gao)于200℃也(ye)能(neng)(neng)(neng)承受數周或更長(chang)時間(jian)仍有彈(dan)性,瞬時可(ke)(ke)耐(nai)(nai)300℃以(yi)上的(de)高(gao)(gao)(gao)溫(wen)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)透氣性好,氧氣透過率(lv)在(zai)合成(cheng)聚(ju)合物中是較(jiao)高(gao)(gao)(gao)的(de)。此(ci)外,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)還具有生(sheng)理惰性、不會導致凝血的(de)突出特性,因此(ci)在(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠分(fen)(fen)類的方法(fa)很多,通常按固化前的形態分(fen)(fen)為(wei)固體(ti)硅(gui)(gui)橡(xiang)膠和(he)(he)液(ye)體(ti)硅(gui)(gui)橡(xiang)膠;按硫化溫(wen)(wen)度分(fen)(fen)為(wei)室溫(wen)(wen)硫化硅(gui)(gui)橡(xiang)膠,高溫(wen)(wen)硫化硅(gui)(gui)橡(xiang)膠;按所(suo)用(yong)單體(ti)的不同,可(ke)分(fen)(fen)為(wei)甲基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)膠,甲基(ji)苯(ben)基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)膠、氟(fu)硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠等;按性能(neng)和(he)(he)用(yong)途的不同又(you)可(ke)分(fen)(fen)為(wei)通用(yong)型(xing)、超耐低溫(wen)(wen)型(xing)、超耐高溫(wen)(wen)型(xing)、高強力型(xing)、耐油型(xing)、醫(yi)用(yong)型(xing)等等。
發展史
硅(gui)橡(xiang)膠(jiao)(jiao)早期(qi)是由(you)美國(guo)(guo)以(yi)三(san)氯(lv)化(hua)鐵為(wei)催化(hua)劑合成的(de)。1945年,硅(gui)橡(xiang)膠(jiao)(jiao)產品(pin)問世。1948年,采(cai)用高比表(biao)面積的(de)氣相法白(bai)炭黑(hei)補強的(de)硅(gui)橡(xiang)膠(jiao)(jiao)研(yan)制成功,使硅(gui)橡(xiang)膠(jiao)(jiao)的(de)性能躍(yue)升到(dao)實(shi)用階段(duan),奠定了現代硅(gui)橡(xiang)膠(jiao)(jiao)生產技術的(de)基(ji)礎。從(cong)二甲基(ji)二氯(lv)硅(gui)烷合成開(kai)始生產硅(gui)橡(xiang)膠(jiao)(jiao)的(de)國(guo)(guo)家有(you)美國(guo)(guo)。俄羅斯、德(de)國(guo)(guo)、日(ri)本、韓(han)國(guo)(guo)和(he)中國(guo)(guo)等。中國(guo)(guo)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)工業(ye)化(hua)研(yan)究(jiu)始于1957年,多家研(yan)究(jiu)所(suo)和(he)企(qi)業(ye)陸續開(kai)發出各種(zhong)硅(gui)橡(xiang)膠(jiao)(jiao)。到(dao)2003年底,中國(guo)(guo)硅(gui)橡(xiang)膠(jiao)(jiao)生產能力為(wei)135千(qian)噸(dun),其中高溫膠(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)化(hua)(hua)(hua)硅(gui)(gui)(gui)橡膠(jiao)(jiao)是(shi)指聚硅(gui)(gui)(gui)氧(yang)(yang)(yang)烷(wan)變成(cheng)彈性體的(de)(de)過程是(shi)經過高溫(110-170℃)硫(liu)化(hua)(hua)(hua)成(cheng)型的(de)(de)。它主(zhu)要(yao)以高分子(zi)量的(de)(de)聚甲基乙(yi)烯基硅(gui)(gui)(gui)氧(yang)(yang)(yang)烷(wan)為(wei)生膠(jiao)(jiao),混入補強(qiang)填(tian)料、硫(liu)化(hua)(hua)(hua)劑等(deng),在(zai)加(jia)熱(re)加(jia)壓下(xia)硫(liu)化(hua)(hua)(hua)成(cheng)彈性體。硅(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)(de)補強(qiang)主(zhu)要(yao)是(shi)各(ge)種類型的(de)(de)白炭黑,可使硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的(de)(de)強(qiang)度增加(jia)數十倍。有時為(wei)了(le)降低成(cheng)本或改善膠(jiao)(jiao)料性能及賦予硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各(ge)種特殊的(de)(de)性能,也(ye)加(jia)入相應(ying)的(de)(de)各(ge)種添加(jia)劑。硫(liu)化(hua)(hua)(hua)劑是(shi)各(ge)種有機過氧(yang)(yang)(yang)化(hua)(hua)(hua)物或加(jia)成(cheng)反應(ying)催(cui)化(hua)(hua)(hua)劑。
加工(gong)成型方法如圖所示。一次硫化(hua)的(de)目(mu)(mu)的(de)是進(jin)行高分子鏈(lian)的(de)交聯(lian)反應(ying);二次硫化(hua)的(de)目(mu)(mu)的(de)是進(jin)行補充(chong)交聯(lian)、驅除硫化(hua)劑分解產物(wu)和其他揮發性(xing)化(hua)合物(wu)以穩定(ding)硫化(hua)膠(jiao)的(de)各項(xiang)性(xing)能。常用(yong)的(de)設備有開放式煉膠(jiao)機(ji)、捏合機(ji)及真空(kong)密煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)顯著的(de)特(te)征是高(gao)溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)強度僅是天然橡(xiang)(xiang)膠(jiao)或某些合成(cheng)橡(xiang)(xiang)膠(jiao)的(de)一(yi)半,但(dan)在200℃以上的(de)高(gao)溫(wen)(wen)(wen)(wen)環境(jing)下(xia)(xia),硅(gui)橡(xiang)(xiang)膠(jiao)仍(reng)能(neng)(neng)(neng)保持(chi)一(yi)定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變(bian)化。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)玻璃化溫(wen)(wen)(wen)(wen)度一(yi)般為-70~-50℃,特(te)殊(shu)配方可達-100℃,表明其低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對(dui)航空、宇航工業的(de)意義重大(da)。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)中(zhong)(zhong)Si-O-Si鍵對(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫(zi)外(wai)線等(deng)(deng)十分穩(wen)定,在不(bu)加(jia)任(ren)何添加(jia)劑的(de)情況(kuang)下(xia)(xia),就具(ju)有優良的(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)具(ju)有優異的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)常溫(wen)(wen)(wen)(wen)下(xia)(xia)的(de)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通用橡(xiang)(xiang)膠(jiao)差,但(dan)在150℃的(de)高(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)低(di)溫(wen)(wen)(wen)(wen)下(xia)(xia),其物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通用橡(xiang)(xiang)膠(jiao)。(6)耐油(you)及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)(xiang)膠(jiao)具(ju)有中(zhong)(zhong)等(deng)(deng)的(de)耐油(you)、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)對(dui)空氣(qi)、氮、氧(yang)(yang)、二(er)氧(yang)(yang)化碳等(deng)(deng)氣(qi)體(ti)(ti)的(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)膠(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)(ti)組織(zhi)不(bu)粘連,具(ju)有抗凝血作(zuo)用,對(dui)肌體(ti)(ti)組織(zhi)的(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作(zuo)為醫用材料。
硅橡膠的用量
據中(zhong)國(guo)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業協(xie)會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)(chan)銷分別(bie)(bie)達到(dao)1927.18萬(wan)(wan)輛(liang)和1930.64萬(wan)(wan)輛(liang),同比(bi)分別(bie)(bie)增長4.63%和4.33%,汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業硅(gui)(gui)橡(xiang)膠的用(yong)(yong)量(liang)約達2.0萬(wan)(wan)t。根據觀研(yan)天(tian)下的新(xin)研(yan)究(jiu),增加(jia)有(you)機(ji)硅(gui)(gui)材料在(zai)(zai)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件方面(mian)的用(yong)(yong)量(liang),可(ke)以大(da)幅度提高(gao)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)的安全性能(neng),因此,汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)(chan)量(liang)和單車(che)(che)用(yong)(yong)量(liang)水平(ping)的提高(gao)都將(jiang)推動汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業對硅(gui)(gui)橡(xiang)膠需求的增加(jia)。國(guo)家鼓(gu)勵自主(zhu)品(pin)牌(pai)的汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件實現(xian)自主(zhu)化,《2012年(nian)(nian)度黨政機(ji)關公(gong)務用(yong)(yong)車(che)(che)選用(yong)(yong)車(che)(che)型(xing)目錄(征求意見稿)》為(wei)自主(zhu)品(pin)牌(pai)擴大(da)在(zai)(zai)政府采(cai)購的市場(chang)份額,為(wei)改(gai)變目前國(guo)內政府采(cai)購以合資(zi)品(pin)牌(pai)產(chan)(chan)品(pin)為(wei)主(zhu)的局面(mian)提供了保障。促(cu)進自主(zhu)品(pin)牌(pai)發展,國(guo)產(chan)(chan)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)業的繁榮將(jiang)為(wei)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)膠的應用(yong)(yong)提供有(you)力保障。預測未來(lai)3年(nian)(nian),我國(guo)室溫硫化硅(gui)(gui)橡(xiang)膠在(zai)(zai)汽(qi)(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)行(xing)業將(jiang)以年(nian)(nian)均20%增長。
此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的(de)非石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約(yue)占非石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消費量(liang)的(de)98%。但(dan)因(yin)為(wei)石(shi)(shi)油(you)(you)價(jia)格的(de)大幅(fu)上漲,同時我(wo)國在硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)關鍵原(yuan)料有(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)生產(chan)技術(shu)方(fang)面取得突(tu)破,有(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)生產(chan)技術(shu)在2005年(nian)前被幾(ji)家跨(kua)國公司壟斷(duan),但(dan)目(mu)前我(wo)國已發展(zhan)成(cheng)(cheng)為(wei)全(quan)球有(you)機(ji)硅(gui)(gui)(gui)(gui)單(dan)體第1大國,這2個方(fang)面原(yuan)因(yin)使硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)價(jia)格從2011年(nian)起(qi)開始(shi)(shi)低于石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約(yue)為(wei)大宗石(shi)(shi)油(you)(you)基(ji)(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為(wei)廉(lian)價(jia)的(de)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并(bing)開始(shi)(shi)大規模(mo)替代石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極(ji)大拓展(zhan)有(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)業的(de)市(shi)場空(kong)間(jian),同時將帶動硅(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(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)品的(de)消費。