硅橡膠是指主鏈(lian)由硅(gui)和(he)氧原子(zi)交(jiao)替(ti)構成(cheng),硅(gui)原子(zi)上通(tong)常連有(you)兩個(ge)有(you)機基團的(de)(de)橡(xiang)膠(jiao)(jiao)。普通(tong)的(de)(de)硅(gui)橡(xiang)膠(jiao)(jiao)主要(yao)由含(han)甲(jia)基和(he)少量(liang)乙烯基的(de)(de)硅(gui)氧鏈(lian)節組成(cheng)。苯(ben)基的(de)(de)引入(ru)(ru)可(ke)(ke)提(ti)高硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)高、低(di)溫性(xing)能,三(san)氟丙(bing)基及(ji)氰基的(de)(de)引入(ru)(ru)則可(ke)(ke)提(ti)高硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)溫及(ji)耐(nai)(nai)油(you)性(xing)能。硅(gui)橡(xiang)膠(jiao)(jiao)耐(nai)(nai)低(di)溫性(xing)能良好,一(yi)般(ban)在-55℃下仍能工(gong)作(zuo)。引入(ru)(ru)苯(ben)基后,可(ke)(ke)達-73℃。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)熱性(xing)能也(ye)很(hen)突出,在180℃下可(ke)(ke)長期工(gong)作(zuo),稍高于200℃也(ye)能承受數周或更長時間仍有(you)彈性(xing),瞬時可(ke)(ke)耐(nai)(nai)300℃以上的(de)(de)高溫。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)透氣(qi)(qi)性(xing)好,氧氣(qi)(qi)透過率在合(he)成(cheng)聚合(he)物中(zhong)是較高的(de)(de)。此外,硅(gui)橡(xiang)膠(jiao)(jiao)還具(ju)有(you)生理(li)惰性(xing)、不會(hui)導致凝血的(de)(de)突出特(te)性(xing),因此在醫用(yong)(yong)領域應用(yong)(yong)廣(guang)泛。
主要品種
硅(gui)橡(xiang)膠分(fen)類的方法很多(duo),通常按固化前的形態分(fen)為固體硅(gui)橡(xiang)膠和(he)液(ye)體硅(gui)橡(xiang)膠;按硫(liu)化溫(wen)(wen)度(du)分(fen)為室溫(wen)(wen)硫(liu)化硅(gui)橡(xiang)膠,高溫(wen)(wen)硫(liu)化硅(gui)橡(xiang)膠;按所用單體的不(bu)同,可分(fen)為甲基(ji)乙烯(xi)基(ji)硅(gui)橡(xiang)膠,甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)橡(xiang)膠、氟硅(gui),腈(jing)硅(gui)橡(xiang)膠等;按性能和(he)用途的不(bu)同又(you)可分(fen)為通用型(xing)(xing)、超耐(nai)低(di)溫(wen)(wen)型(xing)(xing)、超耐(nai)高溫(wen)(wen)型(xing)(xing)、高強(qiang)力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用型(xing)(xing)等等。
發展史
硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)以三氯(lv)化(hua)鐵為(wei)催化(hua)劑(ji)合成的(de)。1945年(nian),硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)(chan)品(pin)問世。1948年(nian),采用高比表面(mian)積的(de)氣相法白炭黑補強的(de)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成功,使(shi)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍升到(dao)(dao)實用階(jie)段,奠定了現代硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)技術的(de)基礎。從二甲(jia)基二氯(lv)硅(gui)烷合成開(kai)始(shi)生(sheng)產(chan)(chan)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)家(jia)(jia)有美國(guo)。俄羅(luo)斯、德國(guo)、日本、韓國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)工業化(hua)研(yan)究始(shi)于1957年(nian),多(duo)家(jia)(jia)研(yan)究所和企業陸(lu)續開(kai)發(fa)出各種硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)(dao)2003年(nian)底(di),中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)能(neng)力為(wei)135千(qian)噸,其(qi)中(zhong)高溫膠(jiao)(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)指聚(ju)硅氧(yang)烷變成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體的過(guo)(guo)(guo)程是(shi)(shi)經過(guo)(guo)(guo)高(gao)溫(110-170℃)硫(liu)(liu)(liu)化(hua)成(cheng)(cheng)(cheng)型的。它主要以高(gao)分子量的聚(ju)甲基乙烯基硅氧(yang)烷為生膠(jiao),混入(ru)(ru)補強(qiang)填料、硫(liu)(liu)(liu)化(hua)劑等,在(zai)加(jia)(jia)熱加(jia)(jia)壓下硫(liu)(liu)(liu)化(hua)成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體。硅橡膠(jiao)的補強(qiang)主要是(shi)(shi)各種(zhong)類型的白炭黑,可使硫(liu)(liu)(liu)化(hua)膠(jiao)的強(qiang)度(du)增加(jia)(jia)數十(shi)倍(bei)。有時為了降低成(cheng)(cheng)(cheng)本或改善膠(jiao)料性(xing)(xing)能及賦予硫(liu)(liu)(liu)化(hua)膠(jiao)各種(zhong)特殊的性(xing)(xing)能,也加(jia)(jia)入(ru)(ru)相應(ying)的各種(zhong)添加(jia)(jia)劑。硫(liu)(liu)(liu)化(hua)劑是(shi)(shi)各種(zhong)有機過(guo)(guo)(guo)氧(yang)化(hua)物或加(jia)(jia)成(cheng)(cheng)(cheng)反應(ying)催化(hua)劑。
加工成型方法(fa)如(ru)圖所(suo)示。一次硫化(hua)(hua)的(de)(de)目的(de)(de)是進行高分子鏈的(de)(de)交聯反應(ying);二次硫化(hua)(hua)的(de)(de)目的(de)(de)是進行補充交聯、驅除(chu)硫化(hua)(hua)劑分解產(chan)物和其(qi)他揮發(fa)性化(hua)(hua)合物以穩定硫化(hua)(hua)膠的(de)(de)各項(xiang)性能。常用(yong)的(de)(de)設備有開放式煉膠機、捏合機及真空密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)特(te)征是高溫(wen)(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)僅是天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半,但在200℃以上(shang)的(de)(de)高溫(wen)(wen)(wen)(wen)(wen)環境下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)保持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明(ming)顯(xian)變(bian)化(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃化(hua)溫(wen)(wen)(wen)(wen)(wen)度(du)一般為(wei)-70~-50℃,特(te)殊配方可達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異(yi)。這對航(hang)(hang)空(kong)、宇航(hang)(hang)工業的(de)(de)意義重(zhong)大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)(yang)、臭(chou)氧(yang)(yang)及紫外(wai)線等(deng)十分穩(wen)定,在不加任(ren)何添(tian)加劑(ji)的(de)(de)情況(kuang)下(xia),就(jiu)具(ju)有優良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有優異(yi)的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好(hao)。(5)物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)(wen)(wen)下(xia)的(de)(de)物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)高溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)(wen)(wen)(wen)下(xia),其物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有中(zhong)等(deng)的(de)(de)耐(nai)油(you)、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空(kong)氣、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)碳等(deng)氣體的(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出(chu)30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人體組(zu)織(zhi)不粘連(lian),具(ju)有抗凝血作用(yong)(yong),對肌(ji)體組(zu)織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少(shao)。特(te)別(bie)適合作為(wei)醫用(yong)(yong)材(cai)料。
硅橡膠的用量
據中國汽車(che)工(gong)業(ye)(ye)協會(hui)統計,2012年,汽車(che)產銷分(fen)別達(da)(da)到(dao)1927.18萬輛(liang)和1930.64萬輛(liang),同(tong)比(bi)分(fen)別增長(chang)(chang)4.63%和4.33%,汽車(che)工(gong)業(ye)(ye)硅橡(xiang)膠(jiao)的(de)用量約達(da)(da)2.0萬t。根據觀研天下的(de)新研究,增加有機硅材料在汽車(che)零部(bu)件方面的(de)用量,可以大(da)幅(fu)度提(ti)高汽車(che)的(de)安全(quan)性能,因(yin)此(ci),汽車(che)產量和單車(che)用量水平的(de)提(ti)高都將推動汽車(che)工(gong)業(ye)(ye)對硅橡(xiang)膠(jiao)需求(qiu)的(de)增加。國家鼓勵自(zi)主(zhu)品牌(pai)的(de)汽車(che)發(fa)展(zhan),關(guan)鍵汽車(che)零部(bu)件實現自(zi)主(zhu)化,《2012年度黨政機關(guan)公務用車(che)選用車(che)型目錄(征求(qiu)意見稿)》為(wei)自(zi)主(zhu)品牌(pai)擴大(da)在政府采(cai)購的(de)市場份(fen)額(e),為(wei)改變目前國內政府采(cai)購以合資品牌(pai)產品為(wei)主(zhu)的(de)局面提(ti)供了保(bao)障。促進自(zi)主(zhu)品牌(pai)發(fa)展(zhan),國產汽車(che)業(ye)(ye)的(de)繁榮將為(wei)汽車(che)膠(jiao)的(de)應用提(ti)供有力(li)保(bao)障。預測未來3年,我(wo)國室溫硫化硅橡(xiang)膠(jiao)在汽車(che)行(xing)業(ye)(ye)將以年均20%增長(chang)(chang)。
此外,硅(gui)橡膠(jiao)(jiao)是重要的(de)非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao)消費量的(de)98%。但因(yin)為石(shi)(shi)油(you)(you)價格的(de)大(da)幅(fu)上漲(zhang),同時我國(guo)在硅(gui)橡膠(jiao)(jiao)的(de)關鍵原料有(you)機(ji)(ji)硅(gui)單體的(de)生產技(ji)術方面取得(de)突破,有(you)機(ji)(ji)硅(gui)單體的(de)生產技(ji)術在2005年前(qian)被(bei)幾家(jia)跨國(guo)公司壟斷,但目(mu)前(qian)我國(guo)已發展成(cheng)(cheng)為全球(qiu)有(you)機(ji)(ji)硅(gui)單體第1大(da)國(guo),這2個方面原因(yin)使(shi)硅(gui)橡膠(jiao)(jiao)的(de)價格從2011年起(qi)開始低于石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao),僅約為大(da)宗石(shi)(shi)油(you)(you)基橡膠(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為廉價的(de)合(he)成(cheng)(cheng)橡膠(jiao)(jiao),并開始大(da)規模(mo)替代石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao)。這將極大(da)拓展有(you)機(ji)(ji)硅(gui)產業(ye)的(de)市場空間,同時將帶(dai)動(dong)硅(gui)油(you)(you)、硅(gui)烷偶聯劑和(he)硅(gui)樹脂等(deng)其(qi)他有(you)機(ji)(ji)硅(gui)產品的(de)消費。