
硅橡膠是指主鏈(lian)由(you)(you)硅(gui)和氧原子交替構(gou)成(cheng),硅(gui)原子上通(tong)常連有(you)兩個有(you)機基團的橡(xiang)膠。普通(tong)的硅(gui)橡(xiang)膠主要由(you)(you)含甲基和少量(liang)乙烯(xi)基的硅(gui)氧鏈(lian)節組成(cheng)。苯基的引入(ru)可(ke)提高硅(gui)橡(xiang)膠的耐高、低溫(wen)(wen)性(xing)(xing)(xing)能(neng)(neng),三氟(fu)丙基及(ji)(ji)氰基的引入(ru)則可(ke)提高硅(gui)橡(xiang)膠的耐溫(wen)(wen)及(ji)(ji)耐油性(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)膠耐低溫(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)良(liang)好,一般在-55℃下(xia)仍能(neng)(neng)工作(zuo)。引入(ru)苯基后,可(ke)達-73℃。硅(gui)橡(xiang)膠的耐熱性(xing)(xing)(xing)能(neng)(neng)也(ye)很突出(chu)(chu),在180℃下(xia)可(ke)長(chang)期工作(zuo),稍高于200℃也(ye)能(neng)(neng)承受數(shu)周或更長(chang)時(shi)(shi)間(jian)仍有(you)彈性(xing)(xing)(xing),瞬時(shi)(shi)可(ke)耐300℃以上的高溫(wen)(wen)。硅(gui)橡(xiang)膠的透(tou)氣性(xing)(xing)(xing)好,氧氣透(tou)過率(lv)在合成(cheng)聚(ju)合物中(zhong)是較高的。此外,硅(gui)橡(xiang)膠還具(ju)有(you)生理惰(duo)性(xing)(xing)(xing)、不會導致凝血(xue)的突出(chu)(chu)特性(xing)(xing)(xing),因(yin)此在醫用領域應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠分(fen)類的方法(fa)很多,通(tong)常按(an)固化(hua)(hua)(hua)前(qian)的形態分(fen)為(wei)固體硅(gui)橡(xiang)(xiang)膠和液體硅(gui)橡(xiang)(xiang)膠;按(an)硫化(hua)(hua)(hua)溫度分(fen)為(wei)室溫硫化(hua)(hua)(hua)硅(gui)橡(xiang)(xiang)膠,高溫硫化(hua)(hua)(hua)硅(gui)橡(xiang)(xiang)膠;按(an)所用(yong)單體的不同,可分(fen)為(wei)甲(jia)基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠,甲(jia)基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠等;按(an)性能(neng)和用(yong)途的不同又可分(fen)為(wei)通(tong)用(yong)型、超(chao)耐(nai)低溫型、超(chao)耐(nai)高溫型、高強力型、耐(nai)油型、醫用(yong)型等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)早期是由美國(guo)(guo)以三氯化(hua)鐵為(wei)催(cui)化(hua)劑合成(cheng)的(de)(de)。1945年(nian)(nian),硅(gui)橡(xiang)(xiang)膠(jiao)產(chan)(chan)(chan)品問(wen)世。1948年(nian)(nian),采用高比表面積的(de)(de)氣(qi)相法白炭(tan)黑(hei)補強的(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)研制(zhi)成(cheng)功,使硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)性能躍升到實用階段(duan),奠(dian)定了現代硅(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產(chan)(chan)(chan)技術(shu)的(de)(de)基礎。從二(er)(er)甲基二(er)(er)氯硅(gui)烷(wan)合成(cheng)開始生(sheng)產(chan)(chan)(chan)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)國(guo)(guo)家有美國(guo)(guo)。俄(e)羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)工業化(hua)研究始于(yu)1957年(nian)(nian),多家研究所和企業陸(lu)續開發出各種硅(gui)橡(xiang)(xiang)膠(jiao)。到2003年(nian)(nian)底,中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產(chan)(chan)(chan)能力為(wei)135千(qian)噸,其中(zhong)高溫膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)是(shi)指(zhi)聚(ju)(ju)硅(gui)(gui)氧烷變成彈性(xing)(xing)體的(de)(de)過(guo)程是(shi)經過(guo)高(gao)溫(110-170℃)硫(liu)(liu)化(hua)成型(xing)的(de)(de)。它主(zhu)要(yao)以高(gao)分子(zi)量的(de)(de)聚(ju)(ju)甲基乙烯(xi)基硅(gui)(gui)氧烷為生膠(jiao)(jiao)(jiao)(jiao),混入補強(qiang)(qiang)填(tian)料、硫(liu)(liu)化(hua)劑(ji)(ji)等(deng),在加熱加壓下硫(liu)(liu)化(hua)成彈性(xing)(xing)體。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)補強(qiang)(qiang)主(zhu)要(yao)是(shi)各(ge)種(zhong)類型(xing)的(de)(de)白炭黑,可使(shi)硫(liu)(liu)化(hua)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強(qiang)(qiang)度增加數(shu)十倍。有時為了降低成本或改(gai)善(shan)膠(jiao)(jiao)(jiao)(jiao)料性(xing)(xing)能及賦予硫(liu)(liu)化(hua)膠(jiao)(jiao)(jiao)(jiao)各(ge)種(zhong)特殊的(de)(de)性(xing)(xing)能,也(ye)加入相應的(de)(de)各(ge)種(zhong)添加劑(ji)(ji)。硫(liu)(liu)化(hua)劑(ji)(ji)是(shi)各(ge)種(zhong)有機過(guo)氧化(hua)物(wu)或加成反應催化(hua)劑(ji)(ji)。
加(jia)工成(cheng)型方法如圖(tu)所示。一次硫化的(de)目的(de)是(shi)進行高分(fen)子鏈的(de)交聯反應(ying);二次硫化的(de)目的(de)是(shi)進行補(bu)充交聯、驅除硫化劑分(fen)解(jie)產物和其他揮發性化合物以穩定硫化膠的(de)各項性能(neng)。常用的(de)設(she)備有(you)開(kai)放式(shi)煉(lian)膠機(ji)、捏合機(ji)及真空密(mi)煉(lian)機(ji)。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特(te)征(zheng)是高(gao)(gao)溫(wen)(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常溫(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度僅是天然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度,且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明顯變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻(bo)璃(li)化溫(wen)(wen)(wen)度一(yi)般(ban)為-70~-50℃,特(te)殊配方可(ke)達(da)-100℃,表明其(qi)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對航空(kong)、宇(yu)航工業的(de)(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧、臭氧及紫外線等十(shi)分穩(wen)定(ding),在不(bu)加任何添加劑的(de)(de)(de)(de)(de)情(qing)況下,就具(ju)有優良的(de)(de)(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有優異的(de)(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)下的(de)(de)(de)(de)(de)物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)(wen)下,其(qi)物理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有中等的(de)(de)(de)(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室(shi)溫(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對空(kong)氣、氮、氧、二氧化碳等氣體的(de)(de)(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組織不(bu)粘連(lian),具(ju)有抗凝血作(zuo)用(yong)(yong),對肌體組織的(de)(de)(de)(de)(de)反(fan)應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特(te)別(bie)適合(he)作(zuo)為醫(yi)用(yong)(yong)材(cai)料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)工業(ye)協會統計,2012年(nian),汽(qi)(qi)車(che)產(chan)銷分(fen)別達到1927.18萬(wan)輛(liang)和(he)1930.64萬(wan)輛(liang),同比(bi)分(fen)別增(zeng)(zeng)長4.63%和(he)4.33%,汽(qi)(qi)車(che)工業(ye)硅橡(xiang)(xiang)膠(jiao)的(de)(de)用(yong)(yong)(yong)量約達2.0萬(wan)t。根據觀(guan)研天下的(de)(de)新研究,增(zeng)(zeng)加有(you)機(ji)硅材料在(zai)汽(qi)(qi)車(che)零部件(jian)方面的(de)(de)用(yong)(yong)(yong)量,可(ke)以(yi)大幅度(du)提(ti)高汽(qi)(qi)車(che)的(de)(de)安(an)全性能,因此,汽(qi)(qi)車(che)產(chan)量和(he)單車(che)用(yong)(yong)(yong)量水(shui)平的(de)(de)提(ti)高都將(jiang)推動汽(qi)(qi)車(che)工業(ye)對硅橡(xiang)(xiang)膠(jiao)需(xu)求的(de)(de)增(zeng)(zeng)加。國(guo)家(jia)鼓勵(li)自主(zhu)品(pin)(pin)(pin)牌(pai)的(de)(de)汽(qi)(qi)車(che)發展,關(guan)鍵汽(qi)(qi)車(che)零部件(jian)實現自主(zhu)化,《2012年(nian)度(du)黨政機(ji)關(guan)公(gong)務用(yong)(yong)(yong)車(che)選用(yong)(yong)(yong)車(che)型目錄(征(zheng)求意見稿)》為(wei)自主(zhu)品(pin)(pin)(pin)牌(pai)擴(kuo)大在(zai)政府采(cai)購(gou)的(de)(de)市場(chang)份額,為(wei)改變(bian)目前(qian)國(guo)內政府采(cai)購(gou)以(yi)合(he)資品(pin)(pin)(pin)牌(pai)產(chan)品(pin)(pin)(pin)為(wei)主(zhu)的(de)(de)局面提(ti)供了(le)保(bao)障。促進(jin)自主(zhu)品(pin)(pin)(pin)牌(pai)發展,國(guo)產(chan)汽(qi)(qi)車(che)業(ye)的(de)(de)繁(fan)榮將(jiang)為(wei)汽(qi)(qi)車(che)膠(jiao)的(de)(de)應用(yong)(yong)(yong)提(ti)供有(you)力保(bao)障。預測未來3年(nian),我國(guo)室溫硫(liu)化硅橡(xiang)(xiang)膠(jiao)在(zai)汽(qi)(qi)車(che)行業(ye)將(jiang)以(yi)年(nian)均20%增(zeng)(zeng)長。
此外(wai),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重(zhong)要的(de)(de)非石(shi)(shi)油基(ji)(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油基(ji)(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消費量(liang)的(de)(de)98%。但因為(wei)(wei)石(shi)(shi)油價(jia)格的(de)(de)大(da)(da)幅(fu)上漲,同時(shi)我國(guo)(guo)在硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關鍵原(yuan)料有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體(ti)的(de)(de)生產(chan)技(ji)術(shu)方(fang)面(mian)取得突破,有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體(ti)的(de)(de)生產(chan)技(ji)術(shu)在2005年前被(bei)幾家跨國(guo)(guo)公司壟斷,但目(mu)前我國(guo)(guo)已發(fa)展成(cheng)為(wei)(wei)全球有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體(ti)第1大(da)(da)國(guo)(guo),這2個方(fang)面(mian)原(yuan)因使(shi)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價(jia)格從2011年起開始低(di)于石(shi)(shi)油基(ji)(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅(jin)約為(wei)(wei)大(da)(da)宗石(shi)(shi)油基(ji)(ji)(ji)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為(wei)(wei)廉價(jia)的(de)(de)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并開始大(da)(da)規(gui)模替代石(shi)(shi)油基(ji)(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)(da)拓展有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)業的(de)(de)市場(chang)空間,同時(shi)將帶動(dong)硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹(shu)脂等(deng)其他(ta)有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)品的(de)(de)消費。