
硅橡膠是(shi)指(zhi)主鏈由硅和氧(yang)(yang)原(yuan)子交替構(gou)成(cheng),硅原(yuan)子上通(tong)常連(lian)有(you)兩個(ge)有(you)機基(ji)團的橡膠。普通(tong)的硅橡膠主要由含(han)甲基(ji)和少量乙(yi)烯(xi)基(ji)的硅氧(yang)(yang)鏈節組成(cheng)。苯基(ji)的引(yin)(yin)入(ru)(ru)可(ke)提(ti)高(gao)硅橡膠的耐(nai)(nai)(nai)高(gao)、低溫(wen)(wen)性(xing)能(neng),三氟丙基(ji)及氰基(ji)的引(yin)(yin)入(ru)(ru)則可(ke)提(ti)高(gao)硅橡膠的耐(nai)(nai)(nai)溫(wen)(wen)及耐(nai)(nai)(nai)油性(xing)能(neng)。硅橡膠耐(nai)(nai)(nai)低溫(wen)(wen)性(xing)能(neng)良好,一(yi)般(ban)在-55℃下仍能(neng)工(gong)作。引(yin)(yin)入(ru)(ru)苯基(ji)后,可(ke)達-73℃。硅橡膠的耐(nai)(nai)(nai)熱性(xing)能(neng)也很突出(chu),在180℃下可(ke)長期(qi)工(gong)作,稍高(gao)于200℃也能(neng)承受(shou)數(shu)周(zhou)或更長時間仍有(you)彈性(xing),瞬(shun)時可(ke)耐(nai)(nai)(nai)300℃以上的高(gao)溫(wen)(wen)。硅橡膠的透氣性(xing)好,氧(yang)(yang)氣透過率在合成(cheng)聚(ju)合物中是(shi)較高(gao)的。此外,硅橡膠還具(ju)有(you)生理惰性(xing)、不會導致凝血的突出(chu)特性(xing),因此在醫(yi)用領域(yu)應用廣(guang)泛。
主要品(pin)種
硅橡膠(jiao)分(fen)(fen)(fen)類(lei)的(de)(de)方法很多,通常按固(gu)化前(qian)的(de)(de)形態分(fen)(fen)(fen)為固(gu)體(ti)硅橡膠(jiao)和(he)液體(ti)硅橡膠(jiao);按硫(liu)化溫(wen)度分(fen)(fen)(fen)為室溫(wen)硫(liu)化硅橡膠(jiao),高溫(wen)硫(liu)化硅橡膠(jiao);按所用單(dan)體(ti)的(de)(de)不同,可分(fen)(fen)(fen)為甲基乙(yi)烯(xi)基硅橡膠(jiao),甲基苯基乙(yi)烯(xi)基硅橡膠(jiao)、氟硅,腈硅橡膠(jiao)等(deng);按性能和(he)用途(tu)的(de)(de)不同又可分(fen)(fen)(fen)為通用型、超耐低溫(wen)型、超耐高溫(wen)型、高強力型、耐油型、醫用型等(deng)等(deng)。
發展史
硅橡(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由美(mei)國(guo)(guo)以三氯化(hua)鐵為催化(hua)劑合成(cheng)(cheng)的。1945年(nian),硅橡(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年(nian),采用高比表面積的氣(qi)相法白炭黑補強的硅橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使硅橡(xiang)膠(jiao)(jiao)(jiao)的性(xing)能(neng)躍升(sheng)到實用階段(duan),奠定了現代硅橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產技術的基礎。從二(er)甲(jia)基二(er)氯硅烷合成(cheng)(cheng)開始生(sheng)產硅橡(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)家有美(mei)國(guo)(guo)。俄羅斯、德(de)國(guo)(guo)、日本(ben)、韓國(guo)(guo)和(he)中國(guo)(guo)等。中國(guo)(guo)硅橡(xiang)膠(jiao)(jiao)(jiao)的工(gong)業(ye)化(hua)研(yan)究始于1957年(nian),多家研(yan)究所和(he)企業(ye)陸續(xu)開發出各種硅橡(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)底,中國(guo)(guo)硅橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產能(neng)力為135千噸(dun),其中高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫(wen)硫化(hua)硅橡膠(jiao)
高(gao)溫硫(liu)化(hua)(hua)硅橡膠是(shi)(shi)指聚硅氧烷變成彈(dan)性體的(de)過程是(shi)(shi)經過高(gao)溫(110-170℃)硫(liu)化(hua)(hua)成型的(de)。它(ta)主(zhu)要以高(gao)分子量的(de)聚甲基乙(yi)烯(xi)基硅氧烷為生膠,混入補強填料、硫(liu)化(hua)(hua)劑(ji)等,在(zai)加(jia)熱加(jia)壓下硫(liu)化(hua)(hua)成彈(dan)性體。硅橡膠的(de)補強主(zhu)要是(shi)(shi)各(ge)種(zhong)類型的(de)白炭(tan)黑(hei),可使硫(liu)化(hua)(hua)膠的(de)強度增加(jia)數(shu)十倍(bei)。有時為了降低成本或(huo)改(gai)善(shan)膠料性能及(ji)賦予硫(liu)化(hua)(hua)膠各(ge)種(zhong)特殊的(de)性能,也加(jia)入相(xiang)應(ying)的(de)各(ge)種(zhong)添加(jia)劑(ji)。硫(liu)化(hua)(hua)劑(ji)是(shi)(shi)各(ge)種(zhong)有機過氧化(hua)(hua)物或(huo)加(jia)成反應(ying)催化(hua)(hua)劑(ji)。
加工成型方(fang)法(fa)如圖所示(shi)。一次硫化(hua)的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)是(shi)進行高分子鏈的(de)(de)(de)(de)交(jiao)聯(lian)反應;二次硫化(hua)的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)是(shi)進行補充交(jiao)聯(lian)、驅(qu)除硫化(hua)劑分解產物和其他揮發性化(hua)合(he)物以穩定硫化(hua)膠的(de)(de)(de)(de)各(ge)項性能。常用的(de)(de)(de)(de)設備有開放式(shi)煉膠機、捏合(he)機及真空密煉機。
主要(yao)性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特征是高溫(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度僅是天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半,但在(zai)200℃以上的(de)(de)高溫(wen)環境下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明(ming)顯變化(hua)。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻璃化(hua)溫(wen)度一般為(wei)-70~-50℃,特殊配方可達-100℃,表明(ming)其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)。這對(dui)航空(kong)、宇航工業(ye)的(de)(de)意義(yi)重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)(yang)、臭氧(yang)(yang)及(ji)紫外線等(deng)(deng)十分穩定,在(zai)不加任何添加劑的(de)(de)情況下(xia),就(jiu)具(ju)(ju)有優(you)良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有優(you)異(yi)的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)下(xia)的(de)(de)物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差(cha),但在(zai)150℃的(de)(de)高溫(wen)和-50℃的(de)(de)低溫(wen)下(xia),其物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于(yu)通(tong)用(yong)(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化(hua)學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有中等(deng)(deng)的(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)空(kong)氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)碳等(deng)(deng)氣(qi)體(ti)(ti)的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒(du),無味,無嗅,與人體(ti)(ti)組織不粘連(lian),具(ju)(ju)有抗凝(ning)血作用(yong)(yong),對(dui)肌體(ti)(ti)組織的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別適合作為(wei)醫用(yong)(yong)材料。
硅橡(xiang)膠的用量
據(ju)中國(guo)(guo)(guo)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)工業(ye)協(xie)會(hui)統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)產銷分別達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比(bi)分別增長4.63%和4.33%,汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)工業(ye)硅(gui)橡(xiang)膠的(de)用(yong)(yong)量約(yue)達2.0萬(wan)t。根(gen)據(ju)觀研(yan)天下的(de)新研(yan)究(jiu),增加(jia)有(you)機硅(gui)材料在汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)零(ling)部件(jian)方面的(de)用(yong)(yong)量,可以大(da)幅(fu)度(du)提(ti)(ti)高汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)的(de)安全性(xing)能,因此(ci),汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)產量和單車(che)用(yong)(yong)量水平的(de)提(ti)(ti)高都將推(tui)動汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)工業(ye)對硅(gui)橡(xiang)膠需求(qiu)的(de)增加(jia)。國(guo)(guo)(guo)家鼓(gu)勵自主(zhu)品(pin)(pin)牌(pai)(pai)的(de)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)發(fa)展,關鍵(jian)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)零(ling)部件(jian)實現自主(zhu)化,《2012年(nian)(nian)度(du)黨政(zheng)機關公(gong)務用(yong)(yong)車(che)選用(yong)(yong)車(che)型目錄(lu)(征求(qiu)意(yi)見稿)》為(wei)自主(zhu)品(pin)(pin)牌(pai)(pai)擴大(da)在政(zheng)府(fu)采(cai)購(gou)的(de)市(shi)場份額,為(wei)改(gai)變(bian)目前國(guo)(guo)(guo)內(nei)政(zheng)府(fu)采(cai)購(gou)以合資品(pin)(pin)牌(pai)(pai)產品(pin)(pin)為(wei)主(zhu)的(de)局面提(ti)(ti)供了(le)保障。促進自主(zhu)品(pin)(pin)牌(pai)(pai)發(fa)展,國(guo)(guo)(guo)產汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)業(ye)的(de)繁榮將為(wei)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)膠的(de)應用(yong)(yong)提(ti)(ti)供有(you)力保障。預測未來3年(nian)(nian),我國(guo)(guo)(guo)室溫硫(liu)化硅(gui)橡(xiang)膠在汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)行業(ye)將以年(nian)(nian)均20%增長。
此(ci)外,硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)是重要的(de)(de)(de)非(fei)石(shi)油(you)(you)基(ji)(ji)(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao),約占(zhan)非(fei)石(shi)油(you)(you)基(ji)(ji)(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)消(xiao)費量的(de)(de)(de)98%。但(dan)因(yin)為石(shi)油(you)(you)價(jia)格的(de)(de)(de)大(da)(da)(da)幅上漲,同(tong)時(shi)我(wo)國(guo)(guo)在(zai)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)關鍵(jian)原(yuan)料有機(ji)(ji)硅單(dan)(dan)體的(de)(de)(de)生(sheng)產(chan)技術(shu)方面取得(de)突破,有機(ji)(ji)硅單(dan)(dan)體的(de)(de)(de)生(sheng)產(chan)技術(shu)在(zai)2005年(nian)前被幾(ji)家跨(kua)國(guo)(guo)公司壟斷,但(dan)目前我(wo)國(guo)(guo)已發展成為全球有機(ji)(ji)硅單(dan)(dan)體第(di)1大(da)(da)(da)國(guo)(guo),這2個(ge)方面原(yuan)因(yin)使硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)價(jia)格從2011年(nian)起開(kai)始(shi)低(di)于石(shi)油(you)(you)基(ji)(ji)(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao),僅約為大(da)(da)(da)宗石(shi)油(you)(you)基(ji)(ji)(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)80%~90%,成為廉價(jia)的(de)(de)(de)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao),并(bing)開(kai)始(shi)大(da)(da)(da)規模替(ti)代石(shi)油(you)(you)基(ji)(ji)(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)(da)(da)拓展有機(ji)(ji)硅產(chan)業的(de)(de)(de)市場空間,同(tong)時(shi)將(jiang)帶動(dong)硅油(you)(you)、硅烷偶聯劑和硅樹脂等其他有機(ji)(ji)硅產(chan)品的(de)(de)(de)消(xiao)費。