硅橡膠是(shi)指(zhi)主鏈由硅和氧原子交替構(gou)成,硅原子上通(tong)常連(lian)有(you)(you)兩個(ge)有(you)(you)機基(ji)(ji)團的(de)(de)(de)(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通(tong)的(de)(de)(de)(de)(de)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主要由含(han)甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)(de)(de)(de)(de)硅氧鏈節組(zu)成。苯基(ji)(ji)的(de)(de)(de)(de)(de)引(yin)入可(ke)提高(gao)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)高(gao)、低(di)溫性(xing)(xing)能(neng),三(san)氟(fu)丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)(de)(de)引(yin)入則(ze)可(ke)提高(gao)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)溫及耐(nai)油性(xing)(xing)能(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐(nai)低(di)溫性(xing)(xing)能(neng)良(liang)好,一(yi)般在-55℃下仍能(neng)工作。引(yin)入苯基(ji)(ji)后,可(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)耐(nai)熱性(xing)(xing)能(neng)也(ye)很(hen)突(tu)出(chu),在180℃下可(ke)長期工作,稍(shao)高(gao)于200℃也(ye)能(neng)承受數周或(huo)更長時間仍有(you)(you)彈性(xing)(xing),瞬時可(ke)耐(nai)300℃以上的(de)(de)(de)(de)(de)高(gao)溫。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)透氣(qi)性(xing)(xing)好,氧氣(qi)透過率在合成聚(ju)合物中是(shi)較高(gao)的(de)(de)(de)(de)(de)。此(ci)外,硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有(you)(you)生理惰性(xing)(xing)、不(bu)會導(dao)致凝血的(de)(de)(de)(de)(de)突(tu)出(chu)特性(xing)(xing),因此(ci)在醫用領域應用廣泛。
主要品(pin)種(zhong)
硅橡膠分類的(de)方法很(hen)多,通常(chang)按(an)固化
前的(de)(de)形態分為(wei)固(gu)體硅(gui)橡(xiang)膠和(he)液體硅(gui)橡(xiang)膠;按(an)硫化溫(wen)度(du)分為(wei)室溫(wen)硫化硅(gui)橡(xiang)膠,高溫(wen)硫化硅(gui)橡(xiang)膠;按(an)所用單體的(de)(de)不同(tong),可分為(wei)甲(jia)基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)膠,甲(jia)基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)膠、氟硅(gui),腈硅(gui)橡(xiang)膠等(deng);按(an)性能(neng)和(he)用途的(de)(de)不同(tong)又可分為(wei)通(tong)用型(xing)、超耐(nai)低溫(wen)型(xing)、超耐(nai)高溫(wen)型(xing)、高強力(li)型(xing)、耐(nai)油(you)型(xing)、醫用型(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由(you)美國以三(san)氯化(hua)鐵(tie)為催化(hua)劑合成(cheng)的。1945年(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)(chan)品問世。1948年(nian),采用高比(bi)表面積的氣相法(fa)白炭黑補強的硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使(shi)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的性能躍升(sheng)到(dao)實(shi)用階段,奠定了現(xian)代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)(chan)技(ji)術的基礎。從二甲基二氯硅(gui)(gui)烷(wan)合成(cheng)開始(shi)生(sheng)(sheng)產(chan)(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的國家有美國。俄羅斯、德國、日(ri)本、韓國和中(zhong)(zhong)(zhong)國等。中(zhong)(zhong)(zhong)國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的工(gong)業(ye)化(hua)研(yan)究始(shi)于1957年(nian),多家研(yan)究所(suo)和企業(ye)陸續開發(fa)出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底(di),中(zhong)(zhong)(zhong)國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)(chan)能力(li)為135千噸(dun),其中(zhong)(zhong)(zhong)高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化(hua)硅橡膠
高(gao)溫硫(liu)(liu)化(hua)(hua)(hua)(hua)硅橡膠(jiao)是(shi)(shi)指聚硅氧烷(wan)變(bian)成(cheng)彈性(xing)體的(de)(de)過程(cheng)是(shi)(shi)經過高(gao)溫(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)(hua)成(cheng)型的(de)(de)。它主要(yao)以高(gao)分子量的(de)(de)聚甲基(ji)乙(yi)烯基(ji)硅氧烷(wan)為生膠(jiao),混(hun)入(ru)補(bu)強(qiang)(qiang)填料、硫(liu)(liu)化(hua)(hua)(hua)(hua)劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓(ya)下(xia)硫(liu)(liu)化(hua)(hua)(hua)(hua)成(cheng)彈性(xing)體。硅橡膠(jiao)的(de)(de)補(bu)強(qiang)(qiang)主要(yao)是(shi)(shi)各種(zhong)(zhong)類型的(de)(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)(hua)(hua)膠(jiao)的(de)(de)強(qiang)(qiang)度增加(jia)(jia)數十倍。有(you)時為了降低成(cheng)本或(huo)改善(shan)膠(jiao)料性(xing)能(neng)及賦(fu)予硫(liu)(liu)化(hua)(hua)(hua)(hua)膠(jiao)各種(zhong)(zhong)特殊的(de)(de)性(xing)能(neng),也加(jia)(jia)入(ru)相應(ying)的(de)(de)各種(zhong)(zhong)添(tian)加(jia)(jia)劑(ji)。硫(liu)(liu)化(hua)(hua)(hua)(hua)劑(ji)是(shi)(shi)各種(zhong)(zhong)有(you)機(ji)過氧化(hua)(hua)(hua)(hua)物(wu)或(huo)加(jia)(jia)成(cheng)反應(ying)催化(hua)(hua)(hua)(hua)劑(ji)。
加工成型(xing)方(fang)法如圖所(suo)示。一(yi)次硫(liu)(liu)化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是進行高分子鏈的(de)(de)(de)交(jiao)聯(lian)反應;二次硫(liu)(liu)化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是進行補充交(jiao)聯(lian)、驅(qu)除硫(liu)(liu)化(hua)(hua)劑分解產物和其他(ta)揮發性化(hua)(hua)合物以穩定硫(liu)(liu)化(hua)(hua)膠的(de)(de)(de)各項性能。常(chang)用的(de)(de)(de)設備(bei)有開(kai)放式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主(zhu)要性能
(1)高(gao)(gao)溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠顯著的(de)(de)特征(zheng)是(shi)高(gao)(gao)溫穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫下硅橡(xiang)膠的(de)(de)強度僅(jin)是(shi)天然(ran)橡(xiang)膠或某些合(he)成(cheng)橡(xiang)膠的(de)(de)一半,但在(zai)200℃以上的(de)(de)高(gao)(gao)溫環境下,硅橡(xiang)膠仍(reng)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)保(bao)持一定的(de)(de)柔(rou)韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)無(wu)明顯變化。(2)低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)硅橡(xiang)膠的(de)(de)玻璃化溫度一般為(wei)-70~-50℃,特殊配方(fang)可(ke)達(da)-100℃,表明其低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)優(you)異。這對(dui)航(hang)空、宇(yu)航(hang)工業的(de)(de)意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠中Si-O-Si鍵對(dui)氧、臭氧及紫(zi)外(wai)線等(deng)十分穩定,在(zai)不(bu)加任何添加劑的(de)(de)情(qing)況下,就具有(you)優(you)良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠具有(you)優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠常(chang)(chang)溫下的(de)(de)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)比通用橡(xiang)膠差,但在(zai)150℃的(de)(de)高(gao)(gao)溫和-50℃的(de)(de)低(di)(di)溫下,其物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)優(you)于通用橡(xiang)膠。(6)耐(nai)油及化學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅橡(xiang)膠具有(you)中等(deng)的(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣體(ti)(ti)透(tou)(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)(neng)。室溫下硅橡(xiang)膠對(dui)空氣、氮、氧、二氧化碳等(deng)氣體(ti)(ti)的(de)(de)透(tou)(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠高(gao)(gao)出30-50倍(bei)。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠無(wu)毒(du),無(wu)味,無(wu)嗅,與(yu)人體(ti)(ti)組織不(bu)粘(zhan)連,具有(you)抗凝血作(zuo)用,對(dui)肌體(ti)(ti)組織的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特別適合(he)作(zuo)為(wei)醫用材料(liao)。
硅橡膠的用量
據中國(guo)汽(qi)車工業(ye)(ye)(ye)協會統(tong)計(ji),2012年(nian),汽(qi)車產(chan)銷分別達(da)到(dao)1927.18萬輛(liang)和(he)1930.64萬輛(liang),同比分別增長4.63%和(he)4.33%,汽(qi)車工業(ye)(ye)(ye)硅(gui)橡膠(jiao)的(de)用(yong)量約達(da)2.0萬t。根據觀研天下的(de)新研究(jiu),增加(jia)有機硅(gui)材料在(zai)汽(qi)車零(ling)部件方面的(de)用(yong)量,可以(yi)大幅度提(ti)(ti)高(gao)汽(qi)車的(de)安全(quan)性(xing)能,因此(ci),汽(qi)車產(chan)量和(he)單車用(yong)量水平(ping)的(de)提(ti)(ti)高(gao)都將(jiang)(jiang)推動汽(qi)車工業(ye)(ye)(ye)對硅(gui)橡膠(jiao)需(xu)求(qiu)的(de)增加(jia)。國(guo)家鼓勵自(zi)(zi)主(zhu)品(pin)(pin)牌的(de)汽(qi)車發展(zhan),關(guan)鍵汽(qi)車零(ling)部件實現自(zi)(zi)主(zhu)化,《2012年(nian)度黨(dang)政機關(guan)公務(wu)用(yong)車選(xuan)用(yong)車型目(mu)錄(征(zheng)求(qiu)意見(jian)稿)》為(wei)自(zi)(zi)主(zhu)品(pin)(pin)牌擴大在(zai)政府采(cai)購(gou)的(de)市場份額,為(wei)改變目(mu)前國(guo)內政府采(cai)購(gou)以(yi)合資品(pin)(pin)牌產(chan)品(pin)(pin)為(wei)主(zhu)的(de)局(ju)面提(ti)(ti)供(gong)了保(bao)(bao)障。促進自(zi)(zi)主(zhu)品(pin)(pin)牌發展(zhan),國(guo)產(chan)汽(qi)車業(ye)(ye)(ye)的(de)繁榮將(jiang)(jiang)為(wei)汽(qi)車膠(jiao)的(de)應(ying)用(yong)提(ti)(ti)供(gong)有力保(bao)(bao)障。預(yu)測(ce)未來3年(nian),我國(guo)室溫硫化硅(gui)橡膠(jiao)在(zai)汽(qi)車行業(ye)(ye)(ye)將(jiang)(jiang)以(yi)年(nian)均20%增長。
此外,硅橡(xiang)膠(jiao)(jiao)是重要的(de)非石(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠(jiao)(jiao)消費量的(de)98%。但因為石(shi)油(you)(you)價格的(de)大(da)幅上漲,同(tong)時(shi)我國(guo)在硅橡(xiang)膠(jiao)(jiao)的(de)關(guan)鍵(jian)原料有(you)機(ji)硅單體的(de)生(sheng)產(chan)技(ji)術方面取得突破,有(you)機(ji)硅單體的(de)生(sheng)產(chan)技(ji)術在2005年前(qian)被(bei)幾(ji)家跨國(guo)公(gong)司(si)壟(long)斷,但目前(qian)我國(guo)已(yi)發展成(cheng)為全球有(you)機(ji)硅單體第1大(da)國(guo),這(zhe)2個(ge)方面原因使(shi)硅橡(xiang)膠(jiao)(jiao)的(de)價格從2011年起開(kai)始(shi)低于石(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠(jiao)(jiao),僅約為大(da)宗石(shi)油(you)(you)基橡(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)為廉(lian)價的(de)合(he)(he)成(cheng)橡(xiang)膠(jiao)(jiao),并開(kai)始(shi)大(da)規模替(ti)代(dai)石(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠(jiao)(jiao)。這(zhe)將(jiang)極大(da)拓展有(you)機(ji)硅產(chan)業的(de)市場(chang)空(kong)間,同(tong)時(shi)將(jiang)帶動硅油(you)(you)、硅烷偶聯劑和(he)硅樹(shu)脂等其他有(you)機(ji)硅產(chan)品的(de)消費。