
硅橡膠是指主(zhu)鏈(lian)(lian)由硅(gui)和(he)氧原(yuan)子(zi)交替構(gou)成,硅(gui)原(yuan)子(zi)上通常連有(you)(you)兩個有(you)(you)機(ji)基(ji)團的(de)橡(xiang)(xiang)膠(jiao)。普通的(de)硅(gui)橡(xiang)(xiang)膠(jiao)主(zhu)要由含甲基(ji)和(he)少量乙烯基(ji)的(de)硅(gui)氧鏈(lian)(lian)節組成。苯基(ji)的(de)引入可(ke)(ke)提高(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)(nai)高(gao)(gao)、低溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)及氰基(ji)的(de)引入則可(ke)(ke)提高(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)(nai)溫(wen)及耐(nai)(nai)(nai)油性(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)耐(nai)(nai)(nai)低溫(wen)性(xing)能(neng)(neng)良好(hao),一般在(zai)(zai)-55℃下仍能(neng)(neng)工作。引入苯基(ji)后,可(ke)(ke)達-73℃。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)(nai)熱性(xing)能(neng)(neng)也很突出,在(zai)(zai)180℃下可(ke)(ke)長期工作,稍高(gao)(gao)于200℃也能(neng)(neng)承受數周或更長時(shi)間仍有(you)(you)彈性(xing),瞬時(shi)可(ke)(ke)耐(nai)(nai)(nai)300℃以(yi)上的(de)高(gao)(gao)溫(wen)。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)透(tou)氣(qi)性(xing)好(hao),氧氣(qi)透(tou)過(guo)率(lv)在(zai)(zai)合成聚合物中是較高(gao)(gao)的(de)。此(ci)外(wai),硅(gui)橡(xiang)(xiang)膠(jiao)還具有(you)(you)生理惰(duo)性(xing)、不會導致凝血的(de)突出特(te)性(xing),因(yin)此(ci)在(zai)(zai)醫(yi)用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)分(fen)類(lei)的方法很多,通常(chang)按(an)固化前的形(xing)態(tai)分(fen)為(wei)固體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)和(he)液體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)硫化溫(wen)度分(fen)為(wei)室溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),高溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)所(suo)用(yong)單體的不同,可分(fen)為(wei)甲基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)等(deng)(deng)(deng);按(an)性能和(he)用(yong)途的不同又可分(fen)為(wei)通用(yong)型、超耐低溫(wen)型、超耐高溫(wen)型、高強(qiang)力型、耐油型、醫用(yong)型等(deng)(deng)(deng)等(deng)(deng)(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)早期(qi)是由美國(guo)(guo)(guo)以(yi)三氯化(hua)鐵為(wei)催化(hua)劑合成的(de)(de)(de)。1945年,硅(gui)(gui)(gui)橡(xiang)膠(jiao)產(chan)品問世(shi)。1948年,采用高比表(biao)面(mian)積的(de)(de)(de)氣相(xiang)法白炭(tan)黑補強的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)研(yan)(yan)制成功,使(shi)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)性能躍(yue)升到實用階段,奠定了現代硅(gui)(gui)(gui)橡(xiang)膠(jiao)生(sheng)(sheng)產(chan)技(ji)術(shu)的(de)(de)(de)基礎。從二甲基二氯硅(gui)(gui)(gui)烷(wan)合成開(kai)始(shi)生(sheng)(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)國(guo)(guo)(guo)家有美國(guo)(guo)(guo)。俄(e)羅斯、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)(zhong)國(guo)(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)工業化(hua)研(yan)(yan)究始(shi)于1957年,多家研(yan)(yan)究所(suo)和企業陸續開(kai)發出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)。到2003年底(di),中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)生(sheng)(sheng)產(chan)能力為(wei)135千(qian)噸,其中(zhong)(zhong)高溫膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)(gao)溫硫化(hua)(hua)(hua)(hua)硅橡膠(jiao)是(shi)指(zhi)聚(ju)硅氧烷變(bian)成(cheng)(cheng)(cheng)彈(dan)(dan)性(xing)體(ti)的(de)(de)過(guo)程是(shi)經過(guo)高(gao)(gao)溫(110-170℃)硫化(hua)(hua)(hua)(hua)成(cheng)(cheng)(cheng)型的(de)(de)。它主(zhu)要(yao)以高(gao)(gao)分子量的(de)(de)聚(ju)甲基(ji)乙烯(xi)基(ji)硅氧烷為(wei)生膠(jiao),混入補(bu)強(qiang)填料(liao)(liao)、硫化(hua)(hua)(hua)(hua)劑(ji)等,在加熱加壓下硫化(hua)(hua)(hua)(hua)成(cheng)(cheng)(cheng)彈(dan)(dan)性(xing)體(ti)。硅橡膠(jiao)的(de)(de)補(bu)強(qiang)主(zhu)要(yao)是(shi)各種(zhong)(zhong)類型的(de)(de)白炭黑,可使硫化(hua)(hua)(hua)(hua)膠(jiao)的(de)(de)強(qiang)度增加數十(shi)倍。有時(shi)為(wei)了降低(di)成(cheng)(cheng)(cheng)本或(huo)改善膠(jiao)料(liao)(liao)性(xing)能及賦(fu)予硫化(hua)(hua)(hua)(hua)膠(jiao)各種(zhong)(zhong)特(te)殊的(de)(de)性(xing)能,也(ye)加入相應(ying)的(de)(de)各種(zhong)(zhong)添加劑(ji)。硫化(hua)(hua)(hua)(hua)劑(ji)是(shi)各種(zhong)(zhong)有機過(guo)氧化(hua)(hua)(hua)(hua)物或(huo)加成(cheng)(cheng)(cheng)反應(ying)催化(hua)(hua)(hua)(hua)劑(ji)。
加(jia)工(gong)成型方法如圖所示。一(yi)次硫化的目(mu)的是(shi)(shi)進行高分子(zi)鏈的交聯反應;二次硫化的目(mu)的是(shi)(shi)進行補充交聯、驅除硫化劑分解產物和其他(ta)揮發性化合物以穩定硫化膠(jiao)的各項性能。常用(yong)的設備(bei)有開放式(shi)煉(lian)膠(jiao)機、捏合機及(ji)真(zhen)空密煉(lian)機。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)特征是高(gao)(gao)溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)強(qiang)度(du)僅(jin)是天然橡(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)(yi)半,但在(zai)200℃以上(shang)的(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)(wen)環(huan)境下(xia),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)保持一(yi)(yi)定的(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和表面(mian)硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明顯(xian)變化(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)(wen)度(du)一(yi)(yi)般為(wei)-70~-50℃,特殊配方可達-100℃,表明其低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異(yi)。這對航空、宇航工業的(de)(de)(de)意義(yi)重(zhong)大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及紫外線等(deng)十分穩(wen)定,在(zai)不(bu)加(jia)任何添(tian)加(jia)劑(ji)的(de)(de)(de)情況下(xia),就具(ju)有(you)(you)優(you)良的(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)優(you)異(yi)的(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)(chang)好。(5)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)(de)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)下(xia),其物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于通用橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐油及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)中等(deng)的(de)(de)(de)耐油、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)對空氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)碳等(deng)氣(qi)體(ti)的(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)膠(jiao)(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅,與人體(ti)組織不(bu)粘連,具(ju)有(you)(you)抗凝(ning)血作(zuo)用,對肌體(ti)組織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)(chang)少。特別適合作(zuo)為(wei)醫用材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)工業協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)產銷分別達(da)到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同(tong)比分別增(zeng)(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)車(che)工業硅橡(xiang)膠的(de)(de)用(yong)量約(yue)達(da)2.0萬(wan)t。根據觀研天下的(de)(de)新研究,增(zeng)(zeng)加有機硅材料(liao)在(zai)汽(qi)(qi)(qi)車(che)零部件方(fang)面(mian)的(de)(de)用(yong)量,可以(yi)(yi)(yi)大幅度(du)提高汽(qi)(qi)(qi)車(che)的(de)(de)安全性能,因此,汽(qi)(qi)(qi)車(che)產量和單車(che)用(yong)量水平的(de)(de)提高都將推(tui)動汽(qi)(qi)(qi)車(che)工業對硅橡(xiang)膠需求的(de)(de)增(zeng)(zeng)加。國家鼓(gu)勵自主品牌(pai)(pai)的(de)(de)汽(qi)(qi)(qi)車(che)發展,關(guan)鍵(jian)汽(qi)(qi)(qi)車(che)零部件實現(xian)自主化,《2012年(nian)度(du)黨政(zheng)(zheng)機關(guan)公(gong)務(wu)用(yong)車(che)選用(yong)車(che)型目錄(征求意見稿)》為自主品牌(pai)(pai)擴大在(zai)政(zheng)(zheng)府采購的(de)(de)市場份額(e),為改變目前國內政(zheng)(zheng)府采購以(yi)(yi)(yi)合資品牌(pai)(pai)產品為主的(de)(de)局面(mian)提供(gong)了保(bao)障。促進自主品牌(pai)(pai)發展,國產汽(qi)(qi)(qi)車(che)業的(de)(de)繁榮(rong)將為汽(qi)(qi)(qi)車(che)膠的(de)(de)應用(yong)提供(gong)有力保(bao)障。預測未來3年(nian),我國室溫(wen)硫化硅橡(xiang)膠在(zai)汽(qi)(qi)(qi)車(che)行業將以(yi)(yi)(yi)年(nian)均20%增(zeng)(zeng)長。
此外,硅(gui)橡(xiang)膠(jiao)(jiao)是重要的(de)(de)非石(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)量的(de)(de)98%。但因為(wei)石(shi)油(you)價格的(de)(de)大(da)(da)幅上漲,同時(shi)我(wo)國(guo)(guo)在硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)關(guan)鍵(jian)原料有(you)機(ji)(ji)硅(gui)單體(ti)的(de)(de)生產(chan)技(ji)術(shu)方(fang)面取得突破(po),有(you)機(ji)(ji)硅(gui)單體(ti)的(de)(de)生產(chan)技(ji)術(shu)在2005年(nian)前被幾家跨國(guo)(guo)公(gong)司壟斷,但目(mu)前我(wo)國(guo)(guo)已發展成(cheng)(cheng)為(wei)全球有(you)機(ji)(ji)硅(gui)單體(ti)第1大(da)(da)國(guo)(guo),這2個方(fang)面原因使硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)價格從2011年(nian)起開始低于(yu)石(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅約為(wei)大(da)(da)宗石(shi)油(you)基(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉價的(de)(de)合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開始大(da)(da)規模替代石(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將極大(da)(da)拓展有(you)機(ji)(ji)硅(gui)產(chan)業的(de)(de)市場(chang)空間,同時(shi)將帶動硅(gui)油(you)、硅(gui)烷(wan)偶聯劑(ji)和(he)硅(gui)樹脂等其他有(you)機(ji)(ji)硅(gui)產(chan)品的(de)(de)消費(fei)。