硅橡膠是(shi)指(zhi)主鏈(lian)由硅和(he)氧原(yuan)子交(jiao)替構成,硅原(yuan)子上(shang)通常連有(you)兩個有(you)機基(ji)(ji)團的(de)(de)(de)橡(xiang)膠(jiao)(jiao)。普通的(de)(de)(de)硅橡(xiang)膠(jiao)(jiao)主要由含甲基(ji)(ji)和(he)少(shao)量乙烯基(ji)(ji)的(de)(de)(de)硅氧鏈(lian)節組成。苯基(ji)(ji)的(de)(de)(de)引(yin)入(ru)可(ke)(ke)提(ti)高硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)(nai)(nai)高、低(di)溫(wen)性(xing)(xing)(xing)能(neng)(neng),三(san)氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引(yin)入(ru)則可(ke)(ke)提(ti)高硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)(nai)(nai)溫(wen)及耐(nai)(nai)(nai)油性(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)耐(nai)(nai)(nai)低(di)溫(wen)性(xing)(xing)(xing)能(neng)(neng)良好,一般在(zai)-55℃下仍能(neng)(neng)工作。引(yin)入(ru)苯基(ji)(ji)后(hou),可(ke)(ke)達-73℃。硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)(nai)(nai)熱性(xing)(xing)(xing)能(neng)(neng)也很突(tu)出,在(zai)180℃下可(ke)(ke)長期工作,稍高于200℃也能(neng)(neng)承受數周或更長時間仍有(you)彈性(xing)(xing)(xing),瞬時可(ke)(ke)耐(nai)(nai)(nai)300℃以上(shang)的(de)(de)(de)高溫(wen)。硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)好,氧氣(qi)(qi)透過率在(zai)合(he)成聚合(he)物中(zhong)是(shi)較高的(de)(de)(de)。此外,硅橡(xiang)膠(jiao)(jiao)還具有(you)生理(li)惰性(xing)(xing)(xing)、不會導致凝血的(de)(de)(de)突(tu)出特性(xing)(xing)(xing),因(yin)此在(zai)醫用領域應用廣泛。
主要品種
硅(gui)橡膠(jiao)(jiao)分(fen)類的方法很多,通(tong)常按固(gu)化(hua)(hua)前的形態分(fen)為(wei)固(gu)體(ti)硅(gui)橡膠(jiao)(jiao)和液體(ti)硅(gui)橡膠(jiao)(jiao);按硫化(hua)(hua)溫(wen)度分(fen)為(wei)室溫(wen)硫化(hua)(hua)硅(gui)橡膠(jiao)(jiao),高溫(wen)硫化(hua)(hua)硅(gui)橡膠(jiao)(jiao);按所(suo)用(yong)單體(ti)的不(bu)同(tong)(tong),可分(fen)為(wei)甲基乙烯基硅(gui)橡膠(jiao)(jiao),甲基苯基乙烯基硅(gui)橡膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡膠(jiao)(jiao)等(deng);按性能和用(yong)途的不(bu)同(tong)(tong)又可分(fen)為(wei)通(tong)用(yong)型(xing)、超(chao)(chao)耐低溫(wen)型(xing)、超(chao)(chao)耐高溫(wen)型(xing)、高強(qiang)力(li)型(xing)、耐油(you)型(xing)、醫用(yong)型(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡膠早期是(shi)由美(mei)國以三氯(lv)化鐵為催化劑合(he)成(cheng)的(de)(de)。1945年,硅(gui)(gui)(gui)橡膠產品問世(shi)。1948年,采(cai)用高比表面積的(de)(de)氣相法白炭黑補強的(de)(de)硅(gui)(gui)(gui)橡膠研制成(cheng)功,使硅(gui)(gui)(gui)橡膠的(de)(de)性能躍(yue)升到(dao)(dao)實(shi)用階段,奠定了現代(dai)硅(gui)(gui)(gui)橡膠生(sheng)產技術的(de)(de)基(ji)礎(chu)。從(cong)二甲基(ji)二氯(lv)硅(gui)(gui)(gui)烷合(he)成(cheng)開始生(sheng)產硅(gui)(gui)(gui)橡膠的(de)(de)國家(jia)有美(mei)國。俄羅斯、德(de)國、日本、韓國和中國等。中國硅(gui)(gui)(gui)橡膠的(de)(de)工業化研究(jiu)始于1957年,多家(jia)研究(jiu)所和企業陸續(xu)開發(fa)出(chu)各種硅(gui)(gui)(gui)橡膠。到(dao)(dao)2003年底(di),中國硅(gui)(gui)(gui)橡膠生(sheng)產能力為135千(qian)噸,其(qi)中高溫膠100千(qian)噸。
高溫硫化硅橡膠
高溫(wen)硫(liu)化(hua)(hua)(hua)硅橡(xiang)膠(jiao)(jiao)是(shi)指聚硅氧烷變(bian)成彈性(xing)體的(de)(de)(de)過程是(shi)經(jing)過高溫(wen)(110-170℃)硫(liu)化(hua)(hua)(hua)成型(xing)的(de)(de)(de)。它主要(yao)以高分子量(liang)的(de)(de)(de)聚甲基乙烯(xi)基硅氧烷為生(sheng)膠(jiao)(jiao),混(hun)入補強填料(liao)、硫(liu)化(hua)(hua)(hua)劑(ji)等,在加(jia)熱加(jia)壓下硫(liu)化(hua)(hua)(hua)成彈性(xing)體。硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)補強主要(yao)是(shi)各(ge)(ge)種類型(xing)的(de)(de)(de)白炭黑,可使硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的(de)(de)(de)強度增加(jia)數(shu)十倍。有時為了(le)降(jiang)低成本或(huo)(huo)改(gai)善(shan)膠(jiao)(jiao)料(liao)性(xing)能(neng)及賦予硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各(ge)(ge)種特(te)殊(shu)的(de)(de)(de)性(xing)能(neng),也加(jia)入相應(ying)的(de)(de)(de)各(ge)(ge)種添加(jia)劑(ji)。硫(liu)化(hua)(hua)(hua)劑(ji)是(shi)各(ge)(ge)種有機(ji)過氧化(hua)(hua)(hua)物或(huo)(huo)加(jia)成反應(ying)催化(hua)(hua)(hua)劑(ji)。
加工成型方法如圖所示(shi)。一次(ci)(ci)硫(liu)化(hua)的目的是進行高分子鏈的交(jiao)聯反應;二(er)次(ci)(ci)硫(liu)化(hua)的目的是進行補充交(jiao)聯、驅除硫(liu)化(hua)劑分解產物(wu)(wu)和其(qi)他揮發性化(hua)合(he)物(wu)(wu)以穩定硫(liu)化(hua)膠的各項性能(neng)。常用的設備有(you)開放(fang)式煉膠機、捏合(he)機及真空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡膠(jiao)顯(xian)著的(de)(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)(de)強度(du)僅(jin)是(shi)天(tian)然(ran)橡膠(jiao)或某些合成橡膠(jiao)的(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環(huan)境下,硅(gui)(gui)(gui)橡膠(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明(ming)顯(xian)變(bian)化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)(de)玻璃(li)化(hua)溫(wen)(wen)(wen)度(du)一(yi)般為(wei)-70~-50℃,特(te)殊(shu)配方可(ke)達-100℃,表明(ming)其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對航(hang)(hang)空(kong)、宇航(hang)(hang)工(gong)業的(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡膠(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及(ji)紫(zi)外線等十分穩定(ding)(ding),在不加任何添加劑(ji)(ji)的(de)(de)(de)情況下,就具(ju)有優良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡膠(jiao)具(ju)有優異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡膠(jiao)常(chang)(chang)溫(wen)(wen)(wen)下的(de)(de)(de)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)(tong)用橡膠(jiao)差,但在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下,其物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通(tong)(tong)用橡膠(jiao)。(6)耐(nai)油(you)及(ji)化(hua)學(xue)試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)(tong)硅(gui)(gui)(gui)橡膠(jiao)具(ju)有中等的(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡膠(jiao)對空(kong)氣(qi)(qi)、氮、氧(yang)(yang)、二(er)氧(yang)(yang)化(hua)碳等氣(qi)(qi)體(ti)的(de)(de)(de)透(tou)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然(ran)橡膠(jiao)高(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡膠(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅,與人體(ti)組(zu)織不粘連,具(ju)有抗凝(ning)血作(zuo)用,對肌(ji)體(ti)組(zu)織的(de)(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特(te)別適合作(zuo)為(wei)醫用材料(liao)。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)工(gong)(gong)(gong)業(ye)(ye)協(xie)會統計,2012年(nian),汽(qi)(qi)(qi)車(che)產(chan)銷分別達(da)到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同比分別增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)工(gong)(gong)(gong)業(ye)(ye)硅(gui)橡膠的(de)用(yong)量約達(da)2.0萬(wan)(wan)t。根(gen)據觀研天下的(de)新研究,增(zeng)加有機硅(gui)材(cai)料在(zai)(zai)汽(qi)(qi)(qi)車(che)零部件方(fang)面(mian)的(de)用(yong)量,可以大幅(fu)度提(ti)高汽(qi)(qi)(qi)車(che)的(de)安全性能,因此,汽(qi)(qi)(qi)車(che)產(chan)量和(he)單車(che)用(yong)量水平的(de)提(ti)高都將推動汽(qi)(qi)(qi)車(che)工(gong)(gong)(gong)業(ye)(ye)對硅(gui)橡膠需求的(de)增(zeng)加。國(guo)家鼓勵自(zi)主(zhu)(zhu)品(pin)牌(pai)的(de)汽(qi)(qi)(qi)車(che)發展(zhan),關鍵汽(qi)(qi)(qi)車(che)零部件實現自(zi)主(zhu)(zhu)化(hua),《2012年(nian)度黨政(zheng)機關公務用(yong)車(che)選用(yong)車(che)型目(mu)錄(征(zheng)求意見稿)》為自(zi)主(zhu)(zhu)品(pin)牌(pai)擴大在(zai)(zai)政(zheng)府采(cai)購的(de)市場份額(e),為改變目(mu)前(qian)國(guo)內政(zheng)府采(cai)購以合資品(pin)牌(pai)產(chan)品(pin)為主(zhu)(zhu)的(de)局面(mian)提(ti)供了保障(zhang)。促進自(zi)主(zhu)(zhu)品(pin)牌(pai)發展(zhan),國(guo)產(chan)汽(qi)(qi)(qi)車(che)業(ye)(ye)的(de)繁(fan)榮將為汽(qi)(qi)(qi)車(che)膠的(de)應用(yong)提(ti)供有力保障(zhang)。預測未來3年(nian),我國(guo)室溫(wen)硫(liu)化(hua)硅(gui)橡膠在(zai)(zai)汽(qi)(qi)(qi)車(che)行業(ye)(ye)將以年(nian)均20%增(zeng)長。
此外,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)是(shi)重要的(de)(de)非(fei)石(shi)油(you)(you)基(ji)合(he)成橡(xiang)(xiang)膠(jiao)(jiao),約占(zhan)非(fei)石(shi)油(you)(you)基(ji)合(he)成橡(xiang)(xiang)膠(jiao)(jiao)消費(fei)量的(de)(de)98%。但(dan)因為(wei)石(shi)油(you)(you)價格的(de)(de)大(da)(da)幅(fu)上漲(zhang),同時我國(guo)(guo)在硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)關(guan)鍵原料有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體的(de)(de)生(sheng)產(chan)技術(shu)(shu)方面取(qu)得(de)突破,有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體的(de)(de)生(sheng)產(chan)技術(shu)(shu)在2005年前(qian)被幾家跨國(guo)(guo)公司(si)壟斷,但(dan)目前(qian)我國(guo)(guo)已(yi)發展成為(wei)全球有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體第1大(da)(da)國(guo)(guo),這2個方面原因使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)價格從2011年起開(kai)始(shi)低(di)于石(shi)油(you)(you)基(ji)合(he)成橡(xiang)(xiang)膠(jiao)(jiao),僅約為(wei)大(da)(da)宗(zong)石(shi)油(you)(you)基(ji)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成為(wei)廉價的(de)(de)合(he)成橡(xiang)(xiang)膠(jiao)(jiao),并開(kai)始(shi)大(da)(da)規模替代(dai)石(shi)油(you)(you)基(ji)合(he)成橡(xiang)(xiang)膠(jiao)(jiao)。這將極大(da)(da)拓展有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)業的(de)(de)市場空(kong)間,同時將帶動硅(gui)(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)(gui)(gui)樹脂等其(qi)他有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)品的(de)(de)消費(fei)。