硅橡膠是指主鏈(lian)由(you)硅(gui)和(he)氧原(yuan)(yuan)子交(jiao)替構成(cheng)(cheng),硅(gui)原(yuan)(yuan)子上(shang)通(tong)(tong)常連有兩個有機基(ji)團的橡(xiang)膠(jiao)。普通(tong)(tong)的硅(gui)橡(xiang)膠(jiao)主要由(you)含甲基(ji)和(he)少(shao)量(liang)乙(yi)烯基(ji)的硅(gui)氧鏈(lian)節組成(cheng)(cheng)。苯基(ji)的引入可(ke)提(ti)高(gao)硅(gui)橡(xiang)膠(jiao)的耐(nai)(nai)高(gao)、低(di)(di)溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)及(ji)氰基(ji)的引入則(ze)可(ke)提(ti)高(gao)硅(gui)橡(xiang)膠(jiao)的耐(nai)(nai)溫(wen)及(ji)耐(nai)(nai)油性(xing)能(neng)(neng)。硅(gui)橡(xiang)膠(jiao)耐(nai)(nai)低(di)(di)溫(wen)性(xing)能(neng)(neng)良好(hao),一(yi)般(ban)在(zai)-55℃下(xia)仍能(neng)(neng)工(gong)作。引入苯基(ji)后,可(ke)達-73℃。硅(gui)橡(xiang)膠(jiao)的耐(nai)(nai)熱性(xing)能(neng)(neng)也(ye)(ye)很突(tu)出(chu),在(zai)180℃下(xia)可(ke)長(chang)期工(gong)作,稍高(gao)于200℃也(ye)(ye)能(neng)(neng)承受數周或(huo)更長(chang)時(shi)間仍有彈性(xing),瞬時(shi)可(ke)耐(nai)(nai)300℃以上(shang)的高(gao)溫(wen)。硅(gui)橡(xiang)膠(jiao)的透氣性(xing)好(hao),氧氣透過率在(zai)合(he)成(cheng)(cheng)聚(ju)合(he)物中是較高(gao)的。此外,硅(gui)橡(xiang)膠(jiao)還具有生理(li)惰(duo)性(xing)、不會導致凝血的突(tu)出(chu)特性(xing),因此在(zai)醫用(yong)領域應用(yong)廣(guang)泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)分(fen)類(lei)的(de)方法很多,通常按(an)固(gu)化(hua)前的(de)形態分(fen)為(wei)(wei)固(gu)體硅(gui)(gui)橡(xiang)膠(jiao)和液體硅(gui)(gui)橡(xiang)膠(jiao);按(an)硫(liu)化(hua)溫度分(fen)為(wei)(wei)室溫硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao),高溫硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao);按(an)所(suo)用(yong)單體的(de)不(bu)同(tong),可(ke)分(fen)為(wei)(wei)甲基(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao),甲基(ji)(ji)(ji)苯基(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)等(deng);按(an)性能(neng)和用(yong)途的(de)不(bu)同(tong)又可(ke)分(fen)為(wei)(wei)通用(yong)型(xing)(xing)、超耐低溫型(xing)(xing)、超耐高溫型(xing)(xing)、高強力(li)型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)橡膠(jiao)早(zao)期是由美(mei)國以(yi)三(san)氯化鐵為催化劑合成的(de)(de)(de)(de)。1945年(nian),硅(gui)橡膠(jiao)產品問世。1948年(nian),采用(yong)高比表面積的(de)(de)(de)(de)氣相法白炭(tan)黑補強的(de)(de)(de)(de)硅(gui)橡膠(jiao)研(yan)制成功,使硅(gui)橡膠(jiao)的(de)(de)(de)(de)性能(neng)(neng)躍升到(dao)實用(yong)階(jie)段(duan),奠定了現代(dai)硅(gui)橡膠(jiao)生(sheng)產技術的(de)(de)(de)(de)基礎。從(cong)二甲基二氯硅(gui)烷合成開始生(sheng)產硅(gui)橡膠(jiao)的(de)(de)(de)(de)國家(jia)(jia)有美(mei)國。俄羅斯、德國、日本、韓國和中(zhong)國等。中(zhong)國硅(gui)橡膠(jiao)的(de)(de)(de)(de)工業化研(yan)究始于1957年(nian),多(duo)家(jia)(jia)研(yan)究所和企(qi)業陸續開發(fa)出各種硅(gui)橡膠(jiao)。到(dao)2003年(nian)底,中(zhong)國硅(gui)橡膠(jiao)生(sheng)產能(neng)(neng)力為135千(qian)噸,其中(zhong)高溫膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)硅(gui)(gui)橡膠(jiao)(jiao)是指聚(ju)硅(gui)(gui)氧(yang)烷(wan)變成彈(dan)性(xing)(xing)體的過程是經過高(gao)溫(wen)(110-170℃)硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)成型的。它主要(yao)以高(gao)分子(zi)量的聚(ju)甲基乙烯基硅(gui)(gui)氧(yang)烷(wan)為生膠(jiao)(jiao),混入(ru)(ru)補(bu)強填料(liao)、硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)劑等,在(zai)加(jia)(jia)(jia)熱(re)加(jia)(jia)(jia)壓下硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)成彈(dan)性(xing)(xing)體。硅(gui)(gui)橡膠(jiao)(jiao)的補(bu)強主要(yao)是各(ge)種(zhong)類型的白炭(tan)黑(hei),可使(shi)硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)膠(jiao)(jiao)的強度增加(jia)(jia)(jia)數十倍。有(you)(you)時為了(le)降(jiang)低(di)成本或(huo)(huo)改善(shan)膠(jiao)(jiao)料(liao)性(xing)(xing)能(neng)及賦予硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)膠(jiao)(jiao)各(ge)種(zhong)特殊(shu)的性(xing)(xing)能(neng),也加(jia)(jia)(jia)入(ru)(ru)相應(ying)(ying)的各(ge)種(zhong)添加(jia)(jia)(jia)劑。硫(liu)(liu)(liu)化(hua)(hua)(hua)(hua)劑是各(ge)種(zhong)有(you)(you)機過氧(yang)化(hua)(hua)(hua)(hua)物或(huo)(huo)加(jia)(jia)(jia)成反應(ying)(ying)催化(hua)(hua)(hua)(hua)劑。
加(jia)工成型方法如圖所示。一次(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是進行高分(fen)子鏈的(de)(de)交(jiao)聯反應(ying);二次(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是進行補充交(jiao)聯、驅除(chu)硫(liu)化(hua)劑分(fen)解產物(wu)(wu)和其他揮(hui)發性化(hua)合物(wu)(wu)以(yi)穩定硫(liu)化(hua)膠(jiao)的(de)(de)各項性能。常(chang)用(yong)的(de)(de)設備(bei)有開放式煉膠(jiao)機(ji)、捏合機(ji)及(ji)真空密煉機(ji)。
主要性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)特(te)征是高溫(wen)穩定(ding)性(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)下(xia)(xia)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)強(qiang)度(du)僅(jin)是天然橡(xiang)膠(jiao)(jiao)或(huo)某些合成橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)一(yi)(yi)半,但在(zai)200℃以上的(de)(de)(de)(de)高溫(wen)環境下(xia)(xia),硅(gui)橡(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一(yi)(yi)定(ding)的(de)(de)(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)和(he)表面(mian)硬度(du),且力(li)學性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明(ming)(ming)顯變化。(2)低溫(wen)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)玻璃化溫(wen)度(du)一(yi)(yi)般為(wei)-70~-50℃,特(te)殊配方可達(da)-100℃,表明(ming)(ming)其低溫(wen)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對(dui)航(hang)空(kong)、宇航(hang)工業(ye)的(de)(de)(de)(de)意義(yi)重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)硅(gui)橡(xiang)膠(jiao)(jiao)中(zhong)(zhong)Si-O-Si鍵對(dui)氧、臭氧及(ji)紫外線等(deng)十(shi)分穩定(ding),在(zai)不(bu)加任何添加劑的(de)(de)(de)(de)情況下(xia)(xia),就具(ju)(ju)有(you)優(you)良的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)(dian)暈(yun)性(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)(dian)弧性(xing)(xing)(xing)(xing)也非常(chang)好。(5)物理(li)機(ji)械性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)常(chang)溫(wen)下(xia)(xia)的(de)(de)(de)(de)物理(li)機(ji)械性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通用(yong)橡(xiang)膠(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)(de)高溫(wen)和(he)-50℃的(de)(de)(de)(de)低溫(wen)下(xia)(xia),其物理(li)機(ji)械性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通用(yong)橡(xiang)膠(jiao)(jiao)。(6)耐(nai)油(you)及(ji)化學試劑性(xing)(xing)(xing)(xing)。普(pu)通硅(gui)橡(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)中(zhong)(zhong)等(deng)的(de)(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)下(xia)(xia)硅(gui)橡(xiang)膠(jiao)(jiao)對(dui)空(kong)氣、氮、氧、二氧化碳(tan)等(deng)氣體的(de)(de)(de)(de)透氣性(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)膠(jiao)(jiao)高出(chu)30-50倍(bei)。(8)生理(li)惰性(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)膠(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與(yu)人體組(zu)織(zhi)不(bu)粘連(lian),具(ju)(ju)有(you)抗(kang)凝血(xue)作用(yong),對(dui)肌(ji)體組(zu)織(zhi)的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)非常(chang)少(shao)。特(te)別適合作為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)(qi)車(che)工(gong)業(ye)協會統計,2012年,汽(qi)(qi)(qi)(qi)車(che)產(chan)銷分(fen)別達(da)到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同比分(fen)別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)工(gong)業(ye)硅橡(xiang)膠(jiao)的用(yong)(yong)(yong)(yong)量(liang)約達(da)2.0萬(wan)(wan)t。根據觀研(yan)天下的新研(yan)究,增(zeng)加有機硅材料在(zai)汽(qi)(qi)(qi)(qi)車(che)零(ling)部(bu)件方面(mian)的用(yong)(yong)(yong)(yong)量(liang),可以大(da)幅(fu)度提高(gao)汽(qi)(qi)(qi)(qi)車(che)的安(an)全性能,因此,汽(qi)(qi)(qi)(qi)車(che)產(chan)量(liang)和(he)單車(che)用(yong)(yong)(yong)(yong)量(liang)水平的提高(gao)都(dou)將推動汽(qi)(qi)(qi)(qi)車(che)工(gong)業(ye)對(dui)硅橡(xiang)膠(jiao)需求(qiu)的增(zeng)加。國(guo)家(jia)鼓勵自(zi)主(zhu)品(pin)牌的汽(qi)(qi)(qi)(qi)車(che)發展(zhan)(zhan),關鍵汽(qi)(qi)(qi)(qi)車(che)零(ling)部(bu)件實現自(zi)主(zhu)化,《2012年度黨政機關公(gong)務(wu)用(yong)(yong)(yong)(yong)車(che)選用(yong)(yong)(yong)(yong)車(che)型目(mu)錄(征求(qiu)意見稿(gao))》為(wei)自(zi)主(zhu)品(pin)牌擴大(da)在(zai)政府采(cai)購的市場(chang)份額,為(wei)改(gai)變(bian)目(mu)前國(guo)內政府采(cai)購以合資(zi)品(pin)牌產(chan)品(pin)為(wei)主(zhu)的局(ju)面(mian)提供了保障(zhang)。促進自(zi)主(zhu)品(pin)牌發展(zhan)(zhan),國(guo)產(chan)汽(qi)(qi)(qi)(qi)車(che)業(ye)的繁榮將為(wei)汽(qi)(qi)(qi)(qi)車(che)膠(jiao)的應用(yong)(yong)(yong)(yong)提供有力保障(zhang)。預測未來3年,我國(guo)室溫硫化硅橡(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)車(che)行(xing)業(ye)將以年均20%增(zeng)長(chang)。
此外(wai),硅(gui)(gui)(gui)橡(xiang)膠(jiao)是(shi)重(zhong)要的(de)(de)(de)(de)(de)非(fei)石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao),約占(zhan)非(fei)石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)消費量的(de)(de)(de)(de)(de)98%。但(dan)因(yin)為(wei)(wei)石(shi)(shi)(shi)油價(jia)格(ge)的(de)(de)(de)(de)(de)大(da)幅上(shang)漲,同(tong)(tong)時(shi)我(wo)國在硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)關(guan)鍵原料有機(ji)硅(gui)(gui)(gui)單(dan)(dan)體的(de)(de)(de)(de)(de)生(sheng)產(chan)技術方面取得突破,有機(ji)硅(gui)(gui)(gui)單(dan)(dan)體的(de)(de)(de)(de)(de)生(sheng)產(chan)技術在2005年前(qian)被幾(ji)家跨(kua)國公司壟斷(duan),但(dan)目前(qian)我(wo)國已發展成(cheng)為(wei)(wei)全球有機(ji)硅(gui)(gui)(gui)單(dan)(dan)體第1大(da)國,這2個方面原因(yin)使硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)價(jia)格(ge)從2011年起開始低于石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao),僅約為(wei)(wei)大(da)宗石(shi)(shi)(shi)油基(ji)(ji)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)80%~90%,成(cheng)為(wei)(wei)廉價(jia)的(de)(de)(de)(de)(de)合成(cheng)橡(xiang)膠(jiao),并開始大(da)規模替(ti)代石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)。這將(jiang)極大(da)拓(tuo)展有機(ji)硅(gui)(gui)(gui)產(chan)業(ye)的(de)(de)(de)(de)(de)市場空間(jian),同(tong)(tong)時(shi)將(jiang)帶動(dong)硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)樹脂等其他有機(ji)硅(gui)(gui)(gui)產(chan)品的(de)(de)(de)(de)(de)消費。