硅橡膠是(shi)指主(zhu)鏈由(you)硅(gui)(gui)(gui)和(he)氧原子交替構成(cheng)(cheng),硅(gui)(gui)(gui)原子上通常連有兩個(ge)有機基(ji)團的(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主(zhu)要(yao)由(you)含甲基(ji)和(he)少量乙烯基(ji)的(de)(de)硅(gui)(gui)(gui)氧鏈節組(zu)成(cheng)(cheng)。苯(ben)基(ji)的(de)(de)引(yin)入(ru)可(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐高(gao)(gao)(gao)、低(di)溫性(xing)(xing)(xing)(xing)能(neng)(neng)(neng),三氟丙(bing)基(ji)及(ji)氰(qing)基(ji)的(de)(de)引(yin)入(ru)則可(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐溫及(ji)耐油性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低(di)溫性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)良(liang)好(hao)(hao),一般(ban)在(zai)-55℃下(xia)仍能(neng)(neng)(neng)工作。引(yin)入(ru)苯(ben)基(ji)后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐熱(re)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)也很(hen)突出,在(zai)180℃下(xia)可(ke)長期工作,稍(shao)高(gao)(gao)(gao)于200℃也能(neng)(neng)(neng)承受數周(zhou)或更長時間仍有彈性(xing)(xing)(xing)(xing),瞬時可(ke)耐300℃以(yi)上的(de)(de)高(gao)(gao)(gao)溫。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)好(hao)(hao),氧氣(qi)透過(guo)率在(zai)合成(cheng)(cheng)聚合物中是(shi)較高(gao)(gao)(gao)的(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有生理惰性(xing)(xing)(xing)(xing)、不會(hui)導致凝血(xue)的(de)(de)突出特性(xing)(xing)(xing)(xing),因此在(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)分(fen)類的方法很(hen)多(duo),通常按(an)固(gu)化(hua)前的形態分(fen)為固(gu)體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)和液體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)硫化(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)所用(yong)單體的不同(tong),可(ke)分(fen)為甲基乙烯基硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基苯基乙烯基硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui)(gui),腈(jing)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)等;按(an)性能和用(yong)途(tu)的不同(tong)又(you)可(ke)分(fen)為通用(yong)型(xing)(xing)、超(chao)耐(nai)低溫(wen)型(xing)(xing)、超(chao)耐(nai)高(gao)溫(wen)型(xing)(xing)、高(gao)強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用(yong)型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)早期是由(you)美國以三(san)氯化鐵為催化劑合(he)(he)成的(de)(de)。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)產品問世。1948年(nian),采用高比表面積(ji)的(de)(de)氣相法白炭黑(hei)補強(qiang)的(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)研(yan)制成功,使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)性能躍升到實用階(jie)段,奠定了現代硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)生產技術的(de)(de)基(ji)礎。從二(er)甲基(ji)二(er)氯硅(gui)(gui)(gui)烷(wan)合(he)(he)成開始生產硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)國家有美國。俄羅斯、德國、日本、韓國和中(zhong)(zhong)國等。中(zhong)(zhong)國硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)工(gong)業化研(yan)究始于1957年(nian),多(duo)家研(yan)究所和企(qi)業陸續開發出各種硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)。到2003年(nian)底,中(zhong)(zhong)國硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)生產能力為135千噸,其中(zhong)(zhong)高溫(wen)膠(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)(liu)(liu)化(hua)硅(gui)橡(xiang)膠(jiao)是指聚硅(gui)氧(yang)烷變成(cheng)彈性體的過程是經過高(gao)溫(wen)(110-170℃)硫(liu)(liu)(liu)(liu)化(hua)成(cheng)型的。它主(zhu)要(yao)以高(gao)分子量的聚甲(jia)基乙烯(xi)基硅(gui)氧(yang)烷為生膠(jiao),混入補強(qiang)填料(liao)、硫(liu)(liu)(liu)(liu)化(hua)劑等,在加熱加壓下(xia)硫(liu)(liu)(liu)(liu)化(hua)成(cheng)彈性體。硅(gui)橡(xiang)膠(jiao)的補強(qiang)主(zhu)要(yao)是各種類型的白炭黑,可(ke)使硫(liu)(liu)(liu)(liu)化(hua)膠(jiao)的強(qiang)度增加數十倍。有時(shi)為了(le)降(jiang)低(di)成(cheng)本或改善膠(jiao)料(liao)性能(neng)(neng)及賦予(yu)硫(liu)(liu)(liu)(liu)化(hua)膠(jiao)各種特(te)殊的性能(neng)(neng),也加入相應的各種添加劑。硫(liu)(liu)(liu)(liu)化(hua)劑是各種有機過氧(yang)化(hua)物或加成(cheng)反應催化(hua)劑。
加工成(cheng)型方(fang)法如圖所示。一次硫(liu)(liu)化(hua)的(de)目(mu)的(de)是進(jin)行高分子鏈的(de)交聯反應;二次硫(liu)(liu)化(hua)的(de)目(mu)的(de)是進(jin)行補充交聯、驅除硫(liu)(liu)化(hua)劑(ji)分解產物和其(qi)他(ta)揮發(fa)性(xing)化(hua)合物以穩定硫(liu)(liu)化(hua)膠(jiao)的(de)各項性(xing)能。常用的(de)設備有開放式煉(lian)膠(jiao)機、捏合機及真空密煉(lian)機。
主要性能
(1)高(gao)(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)特征是(shi)高(gao)(gao)溫(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅(jin)是(shi)天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或(huo)某(mou)些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)半,但在(zai)200℃以(yi)上的(de)(de)(de)高(gao)(gao)溫(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能保持一(yi)定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能無明(ming)顯(xian)變(bian)化。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)玻(bo)璃化溫(wen)度(du)一(yi)般(ban)為-70~-50℃,特殊配方可達-100℃,表明(ming)其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能優(you)異。這(zhe)對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)意義重大。(3)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫外(wai)線(xian)等(deng)(deng)十(shi)分穩定(ding),在(zai)不加任(ren)何添(tian)加劑(ji)的(de)(de)(de)情況下,就(jiu)具(ju)(ju)有(you)優(you)良的(de)(de)(de)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能,耐(nai)(nai)(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常溫(wen)下的(de)(de)(de)物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能比通(tong)用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)高(gao)(gao)溫(wen)和(he)-50℃的(de)(de)(de)低溫(wen)下,其物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能優(you)于(yu)通(tong)用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)(nai)油及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)中等(deng)(deng)的(de)(de)(de)耐(nai)(nai)(nai)(nai)油、耐(nai)(nai)(nai)(nai)溶(rong)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能。室(shi)溫(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化碳等(deng)(deng)氣(qi)體的(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(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)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無毒,無味,無嗅,與人(ren)體組織(zhi)不粘連,具(ju)(ju)有(you)抗凝血作用,對(dui)肌體組織(zhi)的(de)(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少(shao)。特別適(shi)合作為醫用材(cai)料(liao)。
硅橡膠的用量
據(ju)中國(guo)汽車工(gong)業協會(hui)統計,2012年(nian),汽車產銷(xiao)分別達(da)到(dao)1927.18萬輛和(he)(he)1930.64萬輛,同(tong)比分別增長(chang)4.63%和(he)(he)4.33%,汽車工(gong)業硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)用量(liang)(liang)約(yue)達(da)2.0萬t。根據(ju)觀研(yan)天(tian)下(xia)的(de)(de)(de)新研(yan)究(jiu),增加有機硅(gui)材料在(zai)汽車零部件方面的(de)(de)(de)用量(liang)(liang),可以大幅度提(ti)(ti)高汽車的(de)(de)(de)安全(quan)性能,因(yin)此,汽車產量(liang)(liang)和(he)(he)單車用量(liang)(liang)水平的(de)(de)(de)提(ti)(ti)高都將(jiang)(jiang)推(tui)動汽車工(gong)業對硅(gui)橡(xiang)膠(jiao)需(xu)求的(de)(de)(de)增加。國(guo)家鼓勵(li)自主品(pin)(pin)牌(pai)的(de)(de)(de)汽車發展,關鍵汽車零部件實現自主化,《2012年(nian)度黨政機關公務用車選用車型目錄(征(zheng)求意見(jian)稿)》為(wei)(wei)自主品(pin)(pin)牌(pai)擴(kuo)大在(zai)政府(fu)采(cai)購(gou)的(de)(de)(de)市場份額,為(wei)(wei)改變目前國(guo)內政府(fu)采(cai)購(gou)以合資品(pin)(pin)牌(pai)產品(pin)(pin)為(wei)(wei)主的(de)(de)(de)局(ju)面提(ti)(ti)供了保(bao)障(zhang)。促進(jin)自主品(pin)(pin)牌(pai)發展,國(guo)產汽車業的(de)(de)(de)繁(fan)榮將(jiang)(jiang)為(wei)(wei)汽車膠(jiao)的(de)(de)(de)應用提(ti)(ti)供有力保(bao)障(zhang)。預測未(wei)來3年(nian),我國(guo)室溫硫化硅(gui)橡(xiang)膠(jiao)在(zai)汽車行業將(jiang)(jiang)以年(nian)均(jun)20%增長(chang)。
此外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重要的(de)非石(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消費量的(de)98%。但因(yin)為石(shi)油(you)(you)價(jia)格的(de)大(da)幅上漲,同(tong)時(shi)我(wo)國(guo)在硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)關鍵(jian)原(yuan)料有機(ji)硅(gui)單體(ti)的(de)生產技術方面取得突破,有機(ji)硅(gui)單體(ti)的(de)生產技術在2005年(nian)前被(bei)幾家跨國(guo)公司壟斷(duan),但目前我(wo)國(guo)已發展成(cheng)(cheng)為全球有機(ji)硅(gui)單體(ti)第1大(da)國(guo),這2個方面原(yuan)因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)價(jia)格從2011年(nian)起(qi)開始(shi)(shi)低于石(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為大(da)宗石(shi)油(you)(you)基(ji)(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為廉價(jia)的(de)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始(shi)(shi)大(da)規模替代(dai)石(shi)油(you)(you)基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)拓展有機(ji)硅(gui)產業的(de)市場空間(jian),同(tong)時(shi)將帶動硅(gui)油(you)(you)、硅(gui)烷(wan)偶聯(lian)劑和(he)硅(gui)樹(shu)脂等其他有機(ji)硅(gui)產品的(de)消費。