硅橡膠是指主鏈(lian)由(you)硅(gui)和(he)氧原子(zi)交替構(gou)成(cheng),硅(gui)原子(zi)上(shang)通(tong)常連有(you)(you)兩個(ge)有(you)(you)機基(ji)團的(de)橡(xiang)(xiang)膠。普通(tong)的(de)硅(gui)橡(xiang)(xiang)膠主要由(you)含(han)甲基(ji)和(he)少(shao)量乙烯基(ji)的(de)硅(gui)氧鏈(lian)節(jie)組成(cheng)。苯基(ji)的(de)引入可(ke)(ke)提(ti)高(gao)硅(gui)橡(xiang)(xiang)膠的(de)耐高(gao)、低溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)及(ji)氰基(ji)的(de)引入則可(ke)(ke)提(ti)高(gao)硅(gui)橡(xiang)(xiang)膠的(de)耐溫(wen)及(ji)耐油性(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)膠耐低溫(wen)性(xing)能(neng)(neng)良(liang)好,一般在(zai)(zai)-55℃下(xia)仍(reng)能(neng)(neng)工作。引入苯基(ji)后,可(ke)(ke)達-73℃。硅(gui)橡(xiang)(xiang)膠的(de)耐熱性(xing)能(neng)(neng)也很突出(chu),在(zai)(zai)180℃下(xia)可(ke)(ke)長期工作,稍高(gao)于200℃也能(neng)(neng)承受(shou)數周或更長時(shi)間仍(reng)有(you)(you)彈性(xing),瞬時(shi)可(ke)(ke)耐300℃以上(shang)的(de)高(gao)溫(wen)。硅(gui)橡(xiang)(xiang)膠的(de)透氣(qi)性(xing)好,氧氣(qi)透過率在(zai)(zai)合成(cheng)聚合物中是較高(gao)的(de)。此外(wai),硅(gui)橡(xiang)(xiang)膠還具有(you)(you)生理惰性(xing)、不(bu)會導致(zhi)凝血的(de)突出(chu)特性(xing),因此在(zai)(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)分類的(de)方法很多,通常按固(gu)化(hua)前的(de)形態分為(wei)固(gu)體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)和(he)液體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按硫化(hua)溫(wen)度分為(wei)室(shi)溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按所用(yong)單(dan)體的(de)不同(tong),可分為(wei)甲(jia)基乙(yi)烯基硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲(jia)基苯(ben)基乙(yi)烯基硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)等;按性能(neng)和(he)用(yong)途的(de)不同(tong)又可分為(wei)通用(yong)型、超耐低溫(wen)型、超耐高(gao)溫(wen)型、高(gao)強力型、耐油型、醫用(yong)型等等。
發展史
硅橡(xiang)(xiang)膠(jiao)早期是由美(mei)國(guo)(guo)以三氯化鐵為(wei)催化劑合成(cheng)的(de)。1945年(nian),硅橡(xiang)(xiang)膠(jiao)產品問世。1948年(nian),采用高(gao)比(bi)表面積的(de)氣相法白炭(tan)黑補強的(de)硅橡(xiang)(xiang)膠(jiao)研(yan)制成(cheng)功,使硅橡(xiang)(xiang)膠(jiao)的(de)性能躍升(sheng)到實用階段,奠定了(le)現代硅橡(xiang)(xiang)膠(jiao)生(sheng)產技術的(de)基礎。從二(er)(er)甲基二(er)(er)氯硅烷合成(cheng)開始(shi)生(sheng)產硅橡(xiang)(xiang)膠(jiao)的(de)國(guo)(guo)家有美(mei)國(guo)(guo)。俄羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和(he)中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠(jiao)的(de)工業化研(yan)究始(shi)于1957年(nian),多(duo)家研(yan)究所和(he)企業陸(lu)續開發出各種硅橡(xiang)(xiang)膠(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠(jiao)生(sheng)產能力為(wei)135千(qian)噸(dun),其(qi)中(zhong)高(gao)溫膠(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)膠(jiao)是指(zhi)聚(ju)硅(gui)(gui)氧(yang)烷變成彈性體的(de)(de)過(guo)(guo)程是經過(guo)(guo)高(gao)溫(110-170℃)硫(liu)化(hua)(hua)成型的(de)(de)。它主要(yao)以高(gao)分子量的(de)(de)聚(ju)甲(jia)基(ji)乙烯基(ji)硅(gui)(gui)氧(yang)烷為生(sheng)膠(jiao),混(hun)入(ru)補強填料、硫(liu)化(hua)(hua)劑(ji)等,在加(jia)熱加(jia)壓(ya)下硫(liu)化(hua)(hua)成彈性體。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)補強主要(yao)是各(ge)種類型的(de)(de)白炭黑,可使(shi)硫(liu)化(hua)(hua)膠(jiao)的(de)(de)強度增加(jia)數十(shi)倍(bei)。有時為了(le)降低成本或改善(shan)膠(jiao)料性能及賦予硫(liu)化(hua)(hua)膠(jiao)各(ge)種特殊的(de)(de)性能,也加(jia)入(ru)相應的(de)(de)各(ge)種添加(jia)劑(ji)。硫(liu)化(hua)(hua)劑(ji)是各(ge)種有機過(guo)(guo)氧(yang)化(hua)(hua)物或加(jia)成反應催(cui)化(hua)(hua)劑(ji)。
加工成型方(fang)法如圖所示。一次硫(liu)化(hua)(hua)的(de)(de)(de)目(mu)的(de)(de)(de)是(shi)進行(xing)高分子鏈的(de)(de)(de)交(jiao)聯(lian)反應;二(er)次硫(liu)化(hua)(hua)的(de)(de)(de)目(mu)的(de)(de)(de)是(shi)進行(xing)補充交(jiao)聯(lian)、驅除(chu)硫(liu)化(hua)(hua)劑(ji)分解(jie)產(chan)物(wu)和其他(ta)揮發性(xing)化(hua)(hua)合物(wu)以穩定硫(liu)化(hua)(hua)膠的(de)(de)(de)各(ge)項性(xing)能(neng)。常用的(de)(de)(de)設備(bei)有開放式煉(lian)膠機(ji)、捏合機(ji)及真空(kong)密煉(lian)機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)特(te)征是高(gao)溫(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)半,但在200℃以上(shang)的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下(xia)(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明(ming)顯(xian)變化(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻(bo)璃(li)化(hua)溫(wen)(wen)(wen)(wen)度(du)一(yi)般為-70~-50℃,特(te)殊(shu)配方(fang)可(ke)達(da)-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這(zhe)對航空、宇航工業的(de)(de)(de)意義(yi)重(zhong)大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及紫外(wai)線等十分(fen)穩定(ding),在不(bu)加(jia)任何添加(jia)劑的(de)(de)(de)情況下(xia)(xia),就具有優良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有優異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)物(wu)(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差(cha),但在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)下(xia)(xia),其物(wu)(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通(tong)用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有中等的(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對空氣、氮、氧(yang)、二氧(yang)化(hua)碳等氣體的(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與(yu)人體組(zu)織不(bu)粘連,具有抗凝血作(zuo)用,對肌體組(zu)織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)別適(shi)合作(zuo)為醫用材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)協會(hui)統計,2012年(nian)(nian),汽(qi)(qi)(qi)車(che)產(chan)(chan)銷分別達(da)到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同(tong)比(bi)分別增長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)用(yong)量(liang)(liang)約達(da)2.0萬(wan)(wan)t。根據觀研天下(xia)的(de)(de)(de)新研究,增加(jia)有機(ji)硅(gui)材料在汽(qi)(qi)(qi)車(che)零部(bu)件(jian)方(fang)面(mian)的(de)(de)(de)用(yong)量(liang)(liang),可(ke)以大幅(fu)度提(ti)高汽(qi)(qi)(qi)車(che)的(de)(de)(de)安全(quan)性能(neng),因此,汽(qi)(qi)(qi)車(che)產(chan)(chan)量(liang)(liang)和(he)單車(che)用(yong)量(liang)(liang)水平的(de)(de)(de)提(ti)高都將推動(dong)汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)對硅(gui)橡(xiang)膠(jiao)需求(qiu)(qiu)的(de)(de)(de)增加(jia)。國(guo)(guo)家(jia)鼓勵(li)自(zi)(zi)主(zhu)(zhu)品(pin)牌的(de)(de)(de)汽(qi)(qi)(qi)車(che)發展(zhan),關鍵汽(qi)(qi)(qi)車(che)零部(bu)件(jian)實現自(zi)(zi)主(zhu)(zhu)化,《2012年(nian)(nian)度黨政(zheng)機(ji)關公(gong)務用(yong)車(che)選用(yong)車(che)型目錄(lu)(征求(qiu)(qiu)意見(jian)稿)》為自(zi)(zi)主(zhu)(zhu)品(pin)牌擴大在政(zheng)府采(cai)購(gou)的(de)(de)(de)市場(chang)份額,為改變目前國(guo)(guo)內政(zheng)府采(cai)購(gou)以合資品(pin)牌產(chan)(chan)品(pin)為主(zhu)(zhu)的(de)(de)(de)局(ju)面(mian)提(ti)供(gong)了保障(zhang)。促進自(zi)(zi)主(zhu)(zhu)品(pin)牌發展(zhan),國(guo)(guo)產(chan)(chan)汽(qi)(qi)(qi)車(che)業(ye)(ye)(ye)的(de)(de)(de)繁榮將為汽(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)(de)應用(yong)提(ti)供(gong)有力保障(zhang)。預測(ce)未(wei)來3年(nian)(nian),我國(guo)(guo)室(shi)溫硫化硅(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)車(che)行(xing)業(ye)(ye)(ye)將以年(nian)(nian)均(jun)20%增長。
此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)是重要的非石(shi)(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao),約占非石(shi)(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)消(xiao)費(fei)量(liang)的98%。但(dan)因為(wei)石(shi)(shi)(shi)油(you)價(jia)格的大幅(fu)上漲,同時(shi)我國(guo)在(zai)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單體的生產(chan)技(ji)術方(fang)面取(qu)得突(tu)破(po),有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單體的生產(chan)技(ji)術在(zai)2005年(nian)前(qian)被幾(ji)家跨國(guo)公司壟(long)斷,但(dan)目前(qian)我國(guo)已發展成(cheng)為(wei)全球(qiu)有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)單體第1大國(guo),這(zhe)2個方(fang)面原因使硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的價(jia)格從2011年(nian)起開始低于石(shi)(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao),僅約為(wei)大宗石(shi)(shi)(shi)油(you)基(ji)橡(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)為(wei)廉價(jia)的合(he)成(cheng)橡(xiang)(xiang)膠(jiao),并(bing)開始大規模(mo)替代石(shi)(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)。這(zhe)將極大拓展有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)業的市場空間,同時(shi)將帶(dai)動硅(gui)(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)(gui)烷偶(ou)聯劑和硅(gui)(gui)(gui)(gui)樹脂等其他有(you)(you)機(ji)硅(gui)(gui)(gui)(gui)產(chan)品的消(xiao)費(fei)。