
硅橡膠是(shi)指(zhi)主鏈(lian)由(you)(you)硅(gui)(gui)和氧(yang)原子(zi)(zi)交(jiao)替構(gou)成,硅(gui)(gui)原子(zi)(zi)上(shang)通常連有兩個(ge)有機基(ji)(ji)(ji)(ji)團的橡(xiang)膠(jiao)(jiao)。普(pu)通的硅(gui)(gui)橡(xiang)膠(jiao)(jiao)主要(yao)由(you)(you)含甲(jia)基(ji)(ji)(ji)(ji)和少量乙烯基(ji)(ji)(ji)(ji)的硅(gui)(gui)氧(yang)鏈(lian)節(jie)組成。苯(ben)(ben)基(ji)(ji)(ji)(ji)的引入可(ke)提(ti)高(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的耐(nai)高(gao)、低溫(wen)(wen)性(xing)能(neng)(neng),三氟丙(bing)基(ji)(ji)(ji)(ji)及(ji)氰基(ji)(ji)(ji)(ji)的引入則可(ke)提(ti)高(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的耐(nai)溫(wen)(wen)及(ji)耐(nai)油性(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)耐(nai)低溫(wen)(wen)性(xing)能(neng)(neng)良好(hao),一般在(zai)(zai)-55℃下仍(reng)能(neng)(neng)工作(zuo)。引入苯(ben)(ben)基(ji)(ji)(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的耐(nai)熱性(xing)能(neng)(neng)也很突出,在(zai)(zai)180℃下可(ke)長期工作(zuo),稍高(gao)于200℃也能(neng)(neng)承(cheng)受數周或更長時間仍(reng)有彈性(xing),瞬時可(ke)耐(nai)300℃以(yi)上(shang)的高(gao)溫(wen)(wen)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的透氣(qi)性(xing)好(hao),氧(yang)氣(qi)透過率在(zai)(zai)合成聚(ju)合物中是(shi)較高(gao)的。此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)還(huan)具有生理惰性(xing)、不會導(dao)致凝血的突出特性(xing),因此在(zai)(zai)醫用領域應用廣泛。
主要品種
硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類的(de)方法很多,通常按(an)固化(hua)(hua)前的(de)形態分(fen)為固體(ti)(ti)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和液體(ti)(ti)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)硫化(hua)(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)(hua)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫化(hua)(hua)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)所(suo)用單體(ti)(ti)的(de)不同(tong),可(ke)分(fen)為甲基(ji)(ji)乙烯基(ji)(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅,腈(jing)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng)(deng);按(an)性能和用途的(de)不同(tong)又可(ke)分(fen)為通用型(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)、醫用型(xing)(xing)等(deng)(deng)等(deng)(deng)。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)早(zao)期(qi)是由(you)美國(guo)以三氯化(hua)鐵為(wei)催化(hua)劑合成的(de)(de)。1945年(nian)(nian)(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品問世(shi)。1948年(nian)(nian)(nian),采用高比表面積(ji)的(de)(de)氣相法白炭黑補強的(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)研制成功(gong),使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)性能躍升到(dao)實(shi)用階段,奠定了現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)技術的(de)(de)基礎。從二(er)甲基二(er)氯硅(gui)烷(wan)合成開始生(sheng)產(chan)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)國(guo)家(jia)有(you)美國(guo)。俄羅斯、德國(guo)、日本(ben)、韓國(guo)和中(zhong)國(guo)等(deng)。中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)工(gong)業化(hua)研究始于(yu)1957年(nian)(nian)(nian),多家(jia)研究所和企業陸續開發(fa)出(chu)各種(zhong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)(nian)(nian)底,中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)能力為(wei)135千噸,其中(zhong)高溫(wen)膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)(hua)硅橡膠(jiao)是指(zhi)聚硅氧(yang)烷(wan)變(bian)成(cheng)彈性體的(de)(de)過(guo)(guo)程是經過(guo)(guo)高溫(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)成(cheng)型的(de)(de)。它(ta)主要(yao)(yao)以高分子量的(de)(de)聚甲基乙烯基硅氧(yang)烷(wan)為(wei)生(sheng)膠(jiao),混入補(bu)強填料、硫(liu)(liu)化(hua)(hua)(hua)劑(ji)等,在加熱加壓下硫(liu)(liu)化(hua)(hua)(hua)成(cheng)彈性體。硅橡膠(jiao)的(de)(de)補(bu)強主要(yao)(yao)是各(ge)種(zhong)類型的(de)(de)白炭黑(hei),可使硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)的(de)(de)強度(du)增加數十倍。有時(shi)為(wei)了(le)降低成(cheng)本(ben)或(huo)(huo)改善膠(jiao)料性能及(ji)賦予硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)各(ge)種(zhong)特殊(shu)的(de)(de)性能,也(ye)加入相應(ying)的(de)(de)各(ge)種(zhong)添加劑(ji)。硫(liu)(liu)化(hua)(hua)(hua)劑(ji)是各(ge)種(zhong)有機過(guo)(guo)氧(yang)化(hua)(hua)(hua)物或(huo)(huo)加成(cheng)反應(ying)催化(hua)(hua)(hua)劑(ji)。
加(jia)工成型方法如圖所示。一(yi)次(ci)(ci)硫化(hua)的(de)(de)目(mu)的(de)(de)是進行高分(fen)(fen)子鏈的(de)(de)交聯反應;二次(ci)(ci)硫化(hua)的(de)(de)目(mu)的(de)(de)是進行補(bu)充交聯、驅(qu)除硫化(hua)劑(ji)分(fen)(fen)解產(chan)物和其(qi)他揮(hui)發性化(hua)合物以(yi)穩(wen)定硫化(hua)膠的(de)(de)各項性能。常用的(de)(de)設備有開放式煉(lian)膠機(ji)、捏合機(ji)及真空密煉(lian)機(ji)。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)特征是(shi)高溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)下硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)強度僅是(shi)天(tian)(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或(huo)某些(xie)合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)一半(ban),但在200℃以上(shang)的(de)(de)(de)高溫(wen)(wen)環境下,硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍(reng)能(neng)(neng)保持一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面(mian)硬度,且(qie)力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明(ming)顯變化。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)玻璃(li)化溫(wen)(wen)度一般為(wei)-70~-50℃,特殊配(pei)方可達-100℃,表明(ming)其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異(yi)。這對(dui)(dui)航(hang)空、宇航(hang)工(gong)業的(de)(de)(de)意義重(zhong)大。(3)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧(yang)、臭氧(yang)及紫外(wai)線等(deng)(deng)十分穩定(ding),在不加(jia)任何添加(jia)劑的(de)(de)(de)情(qing)況下,就具有(you)優良的(de)(de)(de)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具有(you)優異(yi)的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)(wen)下的(de)(de)(de)物(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在150℃的(de)(de)(de)高溫(wen)(wen)和(he)-50℃的(de)(de)(de)低溫(wen)(wen)下,其物(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)(nai)油(you)及化學(xue)試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具有(you)中等(deng)(deng)的(de)(de)(de)耐(nai)(nai)(nai)油(you)、耐(nai)(nai)(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)下硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)、氮(dan)、氧(yang)、二氧(yang)化碳等(deng)(deng)氣(qi)(qi)體的(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)(tian)然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與(yu)人體組織不粘(zhan)連(lian),具有(you)抗凝血作(zuo)用(yong),對(dui)(dui)肌體組織的(de)(de)(de)反(fan)應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少(shao)。特別適合作(zuo)為(wei)醫用(yong)材(cai)料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工業協會統(tong)計,2012年(nian),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)銷分別達(da)到1927.18萬輛(liang)和1930.64萬輛(liang),同比分別增長4.63%和4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工業硅橡膠(jiao)的(de)(de)用(yong)量約達(da)2.0萬t。根據觀研(yan)天下的(de)(de)新(xin)研(yan)究(jiu),增加有機(ji)硅材(cai)料在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件方面的(de)(de)用(yong)量,可以(yi)大(da)幅度提(ti)(ti)高(gao)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)安全性能,因此(ci),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)量和單車(che)(che)用(yong)量水平的(de)(de)提(ti)(ti)高(gao)都將推動汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工業對(dui)硅橡膠(jiao)需求的(de)(de)增加。國家鼓勵自主(zhu)品(pin)牌(pai)的(de)(de)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)發(fa)展,關鍵(jian)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件實現自主(zhu)化(hua),《2012年(nian)度黨政(zheng)(zheng)機(ji)關公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(征求意見稿)》為(wei)自主(zhu)品(pin)牌(pai)擴大(da)在政(zheng)(zheng)府采(cai)(cai)購的(de)(de)市場份額(e),為(wei)改(gai)變目前國內政(zheng)(zheng)府采(cai)(cai)購以(yi)合資(zi)品(pin)牌(pai)產(chan)品(pin)為(wei)主(zhu)的(de)(de)局(ju)面提(ti)(ti)供了保(bao)障(zhang)。促進自主(zhu)品(pin)牌(pai)發(fa)展,國產(chan)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)業的(de)(de)繁榮將為(wei)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)(de)應用(yong)提(ti)(ti)供有力(li)保(bao)障(zhang)。預測未來3年(nian),我(wo)國室溫硫化(hua)硅橡膠(jiao)在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)行業將以(yi)年(nian)均20%增長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)是(shi)重要的非石(shi)油(you)基合(he)成橡(xiang)膠(jiao),約占非石(shi)油(you)基合(he)成橡(xiang)膠(jiao)消(xiao)費量(liang)的98%。但因(yin)為(wei)(wei)(wei)石(shi)油(you)價(jia)格的大(da)(da)(da)幅上(shang)漲,同(tong)時我國(guo)在(zai)硅(gui)(gui)橡(xiang)膠(jiao)的關鍵原料(liao)有機(ji)(ji)硅(gui)(gui)單體(ti)的生(sheng)產(chan)技術方面(mian)取得(de)突破(po),有機(ji)(ji)硅(gui)(gui)單體(ti)的生(sheng)產(chan)技術在(zai)2005年(nian)前被幾家(jia)跨國(guo)公司壟斷,但目前我國(guo)已發展(zhan)成為(wei)(wei)(wei)全球(qiu)有機(ji)(ji)硅(gui)(gui)單體(ti)第1大(da)(da)(da)國(guo),這2個方面(mian)原因(yin)使硅(gui)(gui)橡(xiang)膠(jiao)的價(jia)格從2011年(nian)起開始(shi)低于石(shi)油(you)基合(he)成橡(xiang)膠(jiao),僅約為(wei)(wei)(wei)大(da)(da)(da)宗石(shi)油(you)基橡(xiang)膠(jiao)的80%~90%,成為(wei)(wei)(wei)廉價(jia)的合(he)成橡(xiang)膠(jiao),并開始(shi)大(da)(da)(da)規模替(ti)代石(shi)油(you)基合(he)成橡(xiang)膠(jiao)。這將(jiang)極(ji)大(da)(da)(da)拓展(zhan)有機(ji)(ji)硅(gui)(gui)產(chan)業的市(shi)場空間(jian),同(tong)時將(jiang)帶動硅(gui)(gui)油(you)、硅(gui)(gui)烷(wan)偶聯劑和(he)硅(gui)(gui)樹脂等其他有機(ji)(ji)硅(gui)(gui)產(chan)品(pin)的消(xiao)費。