
硅橡膠是指主(zhu)鏈由硅(gui)和氧(yang)原子交替(ti)構成(cheng),硅(gui)原子上(shang)通常連(lian)有兩(liang)個有機基(ji)團的(de)(de)(de)(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)(de)(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主(zhu)要由含甲基(ji)和少(shao)量乙烯基(ji)的(de)(de)(de)(de)(de)硅(gui)氧(yang)鏈節組(zu)成(cheng)。苯基(ji)的(de)(de)(de)(de)(de)引入可(ke)提高(gao)(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)高(gao)(gao)(gao)、低溫(wen)(wen)性能(neng),三氟(fu)丙基(ji)及氰(qing)基(ji)的(de)(de)(de)(de)(de)引入則可(ke)提高(gao)(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)溫(wen)(wen)及耐(nai)油性能(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐(nai)低溫(wen)(wen)性能(neng)良好,一般(ban)在(zai)(zai)-55℃下(xia)仍(reng)能(neng)工作。引入苯基(ji)后,可(ke)達-73℃。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)熱性能(neng)也(ye)很(hen)突出,在(zai)(zai)180℃下(xia)可(ke)長期工作,稍(shao)高(gao)(gao)(gao)于200℃也(ye)能(neng)承(cheng)受數周或更長時間仍(reng)有彈性,瞬時可(ke)耐(nai)300℃以上(shang)的(de)(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)透氣(qi)(qi)性好,氧(yang)氣(qi)(qi)透過率在(zai)(zai)合成(cheng)聚合物(wu)中是較(jiao)高(gao)(gao)(gao)的(de)(de)(de)(de)(de)。此外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有生理(li)惰性、不會導致凝(ning)血的(de)(de)(de)(de)(de)突出特(te)性,因(yin)此在(zai)(zai)醫用領域應用廣泛。
主要(yao)品種(zhong)
硅橡(xiang)膠分類(lei)的方法(fa)很多(duo),通常按固化(hua)
前的形態分為固體(ti)硅(gui)橡膠(jiao)和液體(ti)硅(gui)橡膠(jiao);按硫化溫度分為室溫硫化硅(gui)橡膠(jiao),高溫硫化硅(gui)橡膠(jiao);按所用(yong)(yong)單(dan)體(ti)的不同(tong),可分為甲基乙(yi)烯基硅(gui)橡膠(jiao),甲基苯(ben)基乙(yi)烯基硅(gui)橡膠(jiao)、氟硅(gui),腈硅(gui)橡膠(jiao)等(deng);按性能和用(yong)(yong)途的不同(tong)又可分為通(tong)用(yong)(yong)型(xing)(xing)(xing)、超(chao)耐低溫型(xing)(xing)(xing)、超(chao)耐高溫型(xing)(xing)(xing)、高強力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用(yong)(yong)型(xing)(xing)(xing)等(deng)等(deng)。
發(fa)展史(shi)
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早(zao)期(qi)是由美國(guo)(guo)(guo)(guo)以(yi)三氯化鐵為催化劑合成(cheng)的(de)。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產品問世。1948年(nian),采用高比表面積的(de)氣相法白炭黑補強的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研(yan)(yan)制成(cheng)功(gong),使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)性能(neng)躍升到實用階(jie)段,奠定了現代(dai)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產技術的(de)基礎。從二(er)甲基二(er)氯硅(gui)(gui)烷合成(cheng)開始生產硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)國(guo)(guo)(guo)(guo)家有美國(guo)(guo)(guo)(guo)。俄(e)羅斯、德國(guo)(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)(guo)和(he)中(zhong)國(guo)(guo)(guo)(guo)等。中(zhong)國(guo)(guo)(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)工業化研(yan)(yan)究始于(yu)1957年(nian),多家研(yan)(yan)究所和(he)企業陸續開發出(chu)各種(zhong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產能(neng)力為135千噸,其中(zhong)高溫膠(jiao)100千噸。
高溫硫化硅(gui)橡膠(jiao)
高溫硫化(hua)(hua)硅橡(xiang)膠(jiao)(jiao)是指聚(ju)(ju)硅氧(yang)烷變成(cheng)彈(dan)性體的(de)(de)(de)過程(cheng)是經過高溫(110-170℃)硫化(hua)(hua)成(cheng)型的(de)(de)(de)。它主要以高分子(zi)量(liang)的(de)(de)(de)聚(ju)(ju)甲基乙烯基硅氧(yang)烷為生膠(jiao)(jiao),混(hun)入(ru)補強(qiang)填料、硫化(hua)(hua)劑等,在(zai)加熱加壓下硫化(hua)(hua)成(cheng)彈(dan)性體。硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)補強(qiang)主要是各(ge)(ge)種(zhong)(zhong)(zhong)類型的(de)(de)(de)白(bai)炭黑,可使硫化(hua)(hua)膠(jiao)(jiao)的(de)(de)(de)強(qiang)度增加數(shu)十倍。有時為了降低(di)成(cheng)本或改善膠(jiao)(jiao)料性能(neng)及賦予硫化(hua)(hua)膠(jiao)(jiao)各(ge)(ge)種(zhong)(zhong)(zhong)特殊的(de)(de)(de)性能(neng),也加入(ru)相(xiang)應的(de)(de)(de)各(ge)(ge)種(zhong)(zhong)(zhong)添加劑。硫化(hua)(hua)劑是各(ge)(ge)種(zhong)(zhong)(zhong)有機過氧(yang)化(hua)(hua)物或加成(cheng)反(fan)應催化(hua)(hua)劑。
加工成(cheng)型方法如圖所(suo)示。一次硫(liu)化(hua)的目的是進行高分(fen)子鏈的交(jiao)聯(lian)反應;二次硫(liu)化(hua)的目的是進行補充交(jiao)聯(lian)、驅除硫(liu)化(hua)劑分(fen)解(jie)產(chan)物(wu)和其他揮發性化(hua)合物(wu)以穩定(ding)硫(liu)化(hua)膠的各(ge)項(xiang)性能。常用的設備有(you)開放式煉膠機(ji)、捏合機(ji)及(ji)真空密煉機(ji)。
主(zhu)要性(xing)能
(1)高溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)特征是高溫穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度(du)(du)僅是天(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某(mou)些合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)一半,但在200℃以上的(de)(de)(de)(de)高溫環境下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持(chi)一定的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬(ying)度(du)(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化(hua)。(2)低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)溫度(du)(du)一般為-70~-50℃,特殊配方可達-100℃,表明其低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)。這(zhe)對航空、宇航工業(ye)的(de)(de)(de)(de)意義重大(da)。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)(ji)紫外(wai)線等十分穩定,在不(bu)加任何添加劑(ji)的(de)(de)(de)(de)情(qing)況下(xia),就具(ju)(ju)有(you)(you)優(you)良的(de)(de)(de)(de)耐候(hou)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)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)優(you)異(yi)的(de)(de)(de)(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(he)耐電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫下(xia)的(de)(de)(de)(de)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)高溫和(he)-50℃的(de)(de)(de)(de)低溫下(xia),其物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐油及(ji)(ji)化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)中(zhong)等的(de)(de)(de)(de)耐油、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)、氮、氧(yang)、二氧(yang)化(hua)碳等氣(qi)體的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與(yu)人(ren)體組織(zhi)不(bu)粘連,具(ju)(ju)有(you)(you)抗凝血作用(yong)(yong),對肌(ji)體組織(zhi)的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別適合作為醫用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)車(che)(che)(che)(che)工業(ye)協會統計,2012年,汽(qi)車(che)(che)(che)(che)產(chan)銷分(fen)別(bie)達(da)到1927.18萬輛和1930.64萬輛,同比(bi)分(fen)別(bie)增(zeng)(zeng)長(chang)4.63%和4.33%,汽(qi)車(che)(che)(che)(che)工業(ye)硅(gui)橡(xiang)膠(jiao)的用(yong)(yong)量約達(da)2.0萬t。根(gen)據觀研天下(xia)的新研究,增(zeng)(zeng)加有機硅(gui)材料在汽(qi)車(che)(che)(che)(che)零部件(jian)方面的用(yong)(yong)量,可以大(da)幅(fu)度(du)提高汽(qi)車(che)(che)(che)(che)的安(an)全性能(neng),因此(ci),汽(qi)車(che)(che)(che)(che)產(chan)量和單(dan)車(che)(che)(che)(che)用(yong)(yong)量水平(ping)的提高都將推動汽(qi)車(che)(che)(che)(che)工業(ye)對硅(gui)橡(xiang)膠(jiao)需求(qiu)的增(zeng)(zeng)加。國(guo)(guo)家鼓勵自主(zhu)品(pin)牌的汽(qi)車(che)(che)(che)(che)發展,關(guan)鍵汽(qi)車(che)(che)(che)(che)零部件(jian)實現自主(zhu)化,《2012年度(du)黨政機關(guan)公(gong)務用(yong)(yong)車(che)(che)(che)(che)選用(yong)(yong)車(che)(che)(che)(che)型目錄(征求(qiu)意見稿(gao))》為(wei)自主(zhu)品(pin)牌擴大(da)在政府采購的市場份額(e),為(wei)改變(bian)目前國(guo)(guo)內政府采購以合資品(pin)牌產(chan)品(pin)為(wei)主(zhu)的局面提供(gong)了保(bao)障(zhang)。促進自主(zhu)品(pin)牌發展,國(guo)(guo)產(chan)汽(qi)車(che)(che)(che)(che)業(ye)的繁榮(rong)將為(wei)汽(qi)車(che)(che)(che)(che)膠(jiao)的應用(yong)(yong)提供(gong)有力保(bao)障(zhang)。預測(ce)未來3年,我國(guo)(guo)室溫硫化硅(gui)橡(xiang)膠(jiao)在汽(qi)車(che)(che)(che)(che)行(xing)業(ye)將以年均20%增(zeng)(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)是(shi)重要的非(fei)石油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao),約占非(fei)石油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)消(xiao)費(fei)量的98%。但(dan)(dan)因為石油(you)價格的大(da)幅上(shang)漲(zhang),同(tong)時(shi)我國(guo)(guo)在(zai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)(gui)(gui)單體的生產(chan)(chan)技(ji)術(shu)方面(mian)取得突破,有(you)(you)機(ji)硅(gui)(gui)(gui)單體的生產(chan)(chan)技(ji)術(shu)在(zai)2005年(nian)前被幾家跨國(guo)(guo)公司壟斷,但(dan)(dan)目前我國(guo)(guo)已發(fa)展(zhan)成(cheng)(cheng)為全球有(you)(you)機(ji)硅(gui)(gui)(gui)單體第1大(da)國(guo)(guo),這2個方面(mian)原因使硅(gui)(gui)(gui)橡(xiang)膠(jiao)的價格從2011年(nian)起開(kai)(kai)始低于石油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao),僅約為大(da)宗石油(you)基橡(xiang)膠(jiao)的80%~90%,成(cheng)(cheng)為廉價的合(he)成(cheng)(cheng)橡(xiang)膠(jiao),并開(kai)(kai)始大(da)規模替代石油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)。這將極大(da)拓展(zhan)有(you)(you)機(ji)硅(gui)(gui)(gui)產(chan)(chan)業的市場空間,同(tong)時(shi)將帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)樹脂等(deng)其他有(you)(you)機(ji)硅(gui)(gui)(gui)產(chan)(chan)品的消(xiao)費(fei)。