
硅橡膠是指主鏈由硅(gui)(gui)(gui)和(he)(he)氧(yang)(yang)原子交替構成,硅(gui)(gui)(gui)原子上(shang)通常連(lian)有(you)兩個有(you)機(ji)基(ji)團的橡膠。普通的硅(gui)(gui)(gui)橡膠主要由含(han)甲基(ji)和(he)(he)少量乙烯基(ji)的硅(gui)(gui)(gui)氧(yang)(yang)鏈節組成。苯基(ji)的引入(ru)(ru)可提高(gao)硅(gui)(gui)(gui)橡膠的耐(nai)(nai)高(gao)、低溫性(xing)(xing)能,三氟丙基(ji)及氰(qing)基(ji)的引入(ru)(ru)則可提高(gao)硅(gui)(gui)(gui)橡膠的耐(nai)(nai)溫及耐(nai)(nai)油性(xing)(xing)能。硅(gui)(gui)(gui)橡膠耐(nai)(nai)低溫性(xing)(xing)能良好,一(yi)般在(zai)(zai)(zai)-55℃下仍能工(gong)(gong)作。引入(ru)(ru)苯基(ji)后,可達(da)-73℃。硅(gui)(gui)(gui)橡膠的耐(nai)(nai)熱性(xing)(xing)能也很突(tu)出,在(zai)(zai)(zai)180℃下可長期工(gong)(gong)作,稍高(gao)于200℃也能承受數周或更長時(shi)(shi)間仍有(you)彈(dan)性(xing)(xing),瞬(shun)時(shi)(shi)可耐(nai)(nai)300℃以(yi)上(shang)的高(gao)溫。硅(gui)(gui)(gui)橡膠的透氣性(xing)(xing)好,氧(yang)(yang)氣透過率在(zai)(zai)(zai)合(he)(he)成聚(ju)合(he)(he)物中是較高(gao)的。此外,硅(gui)(gui)(gui)橡膠還具有(you)生理惰性(xing)(xing)、不(bu)會導致(zhi)凝血的突(tu)出特性(xing)(xing),因此在(zai)(zai)(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分類的方法很多,通(tong)(tong)常(chang)按(an)固化前的形態分為(wei)(wei)固體(ti)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和(he)液體(ti)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)硫(liu)化溫(wen)度(du)分為(wei)(wei)室溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)(gao)溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)所用(yong)單體(ti)的不同,可分為(wei)(wei)甲(jia)(jia)基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲(jia)(jia)基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等;按(an)性能和(he)用(yong)途的不同又可分為(wei)(wei)通(tong)(tong)用(yong)型(xing)、超(chao)耐低溫(wen)型(xing)、超(chao)耐高(gao)(gao)溫(wen)型(xing)、高(gao)(gao)強(qiang)力型(xing)、耐油型(xing)、醫(yi)用(yong)型(xing)等等。
發展史
硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)早期是由美國(guo)(guo)(guo)以三(san)氯(lv)化(hua)鐵為(wei)催(cui)化(hua)劑合成(cheng)(cheng)的(de)(de)(de)。1945年(nian)(nian)(nian)(nian),硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)產(chan)品(pin)問世。1948年(nian)(nian)(nian)(nian),采用(yong)高比表面積的(de)(de)(de)氣相法白炭(tan)黑補強的(de)(de)(de)硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)研制成(cheng)(cheng)功,使硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)性能躍升到(dao)實用(yong)階段,奠定了現代(dai)硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)技術的(de)(de)(de)基礎。從二甲基二氯(lv)硅(gui)烷合成(cheng)(cheng)開(kai)始(shi)生產(chan)硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)國(guo)(guo)(guo)家有美國(guo)(guo)(guo)。俄(e)羅斯(si)、德國(guo)(guo)(guo)、日(ri)本、韓國(guo)(guo)(guo)和(he)中(zhong)國(guo)(guo)(guo)等。中(zhong)國(guo)(guo)(guo)硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)工業(ye)化(hua)研究始(shi)于1957年(nian)(nian)(nian)(nian),多家研究所和(he)企業(ye)陸續開(kai)發出各種硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)。到(dao)2003年(nian)(nian)(nian)(nian)底(di),中(zhong)國(guo)(guo)(guo)硅(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)能力為(wei)135千噸(dun),其(qi)中(zhong)高溫膠(jiao)(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫化(hua)硅(gui)橡膠是(shi)指聚硅(gui)氧烷變成(cheng)(cheng)彈性(xing)體的(de)(de)過程是(shi)經過高(gao)溫(110-170℃)硫化(hua)成(cheng)(cheng)型的(de)(de)。它主(zhu)要(yao)以高(gao)分子量的(de)(de)聚甲(jia)基(ji)乙烯基(ji)硅(gui)氧烷為生膠,混入補強(qiang)(qiang)填料、硫化(hua)劑(ji)等,在加熱(re)加壓下硫化(hua)成(cheng)(cheng)彈性(xing)體。硅(gui)橡膠的(de)(de)補強(qiang)(qiang)主(zhu)要(yao)是(shi)各種(zhong)類型的(de)(de)白炭黑,可(ke)使硫化(hua)膠的(de)(de)強(qiang)(qiang)度增加數十倍。有(you)時為了降低成(cheng)(cheng)本(ben)或改善膠料性(xing)能(neng)及(ji)賦予(yu)硫化(hua)膠各種(zhong)特(te)殊的(de)(de)性(xing)能(neng),也加入相應的(de)(de)各種(zhong)添(tian)加劑(ji)。硫化(hua)劑(ji)是(shi)各種(zhong)有(you)機過氧化(hua)物或加成(cheng)(cheng)反應催(cui)化(hua)劑(ji)。
加工成型方(fang)法如圖(tu)所(suo)示。一次硫化(hua)(hua)的目的是(shi)進行高分(fen)子(zi)鏈(lian)的交聯(lian)反(fan)應;二次硫化(hua)(hua)的目的是(shi)進行補充交聯(lian)、驅除硫化(hua)(hua)劑分(fen)解產物和(he)其(qi)他揮發性(xing)化(hua)(hua)合物以(yi)穩定硫化(hua)(hua)膠的各(ge)項性(xing)能(neng)。常用的設備有(you)開放式煉膠機、捏合機及(ji)真空(kong)密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著(zhu)的(de)(de)(de)特(te)征(zheng)是高溫(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度僅是天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或(huo)某(mou)些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在200℃以上(shang)的(de)(de)(de)高溫(wen)(wen)(wen)(wen)環境下(xia)(xia),硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)保持一定的(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)和(he)表面硬度,且力(li)學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明顯變(bian)化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊(shu)配方可達(da)-100℃,表明其(qi)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異。這對航空、宇航工業的(de)(de)(de)意義重大。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及紫外線等(deng)十分穩定,在不加任何(he)添(tian)加劑(ji)的(de)(de)(de)情況下(xia)(xia),就具(ju)有(you)優良的(de)(de)(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)優異的(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)和(he)耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比(bi)通用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)下(xia)(xia),其(qi)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐油(you)及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)。普通硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)的(de)(de)(de)耐油(you)、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透(tou)(tou)過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)(qi)、氮、氧(yang)、二氧(yang)化碳等(deng)氣(qi)(qi)體(ti)的(de)(de)(de)透(tou)(tou)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒(du),無(wu)味,無(wu)嗅,與(yu)人體(ti)組織不粘連,具(ju)有(you)抗凝血作(zuo)用(yong),對肌體(ti)組織的(de)(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適(shi)合作(zuo)為醫用(yong)材料。
硅橡膠的用量
據中國汽車(che)(che)(che)工(gong)業(ye)(ye)協會統計,2012年,汽車(che)(che)(che)產銷分(fen)別達到1927.18萬輛(liang)和(he)1930.64萬輛(liang),同比分(fen)別增(zeng)長4.63%和(he)4.33%,汽車(che)(che)(che)工(gong)業(ye)(ye)硅(gui)(gui)橡膠(jiao)的(de)(de)用(yong)(yong)量約(yue)達2.0萬t。根(gen)據觀研天下的(de)(de)新(xin)研究(jiu),增(zeng)加(jia)有機(ji)硅(gui)(gui)材(cai)料在(zai)汽車(che)(che)(che)零部件(jian)方面(mian)的(de)(de)用(yong)(yong)量,可以大幅(fu)度提(ti)高汽車(che)(che)(che)的(de)(de)安全性能,因此,汽車(che)(che)(che)產量和(he)單(dan)車(che)(che)(che)用(yong)(yong)量水平的(de)(de)提(ti)高都將推(tui)動汽車(che)(che)(che)工(gong)業(ye)(ye)對(dui)硅(gui)(gui)橡膠(jiao)需求的(de)(de)增(zeng)加(jia)。國家鼓勵自(zi)(zi)主(zhu)品(pin)牌的(de)(de)汽車(che)(che)(che)發展(zhan),關(guan)鍵汽車(che)(che)(che)零部件(jian)實現自(zi)(zi)主(zhu)化,《2012年度黨政(zheng)(zheng)機(ji)關(guan)公務用(yong)(yong)車(che)(che)(che)選用(yong)(yong)車(che)(che)(che)型目(mu)錄(lu)(征求意見稿)》為(wei)自(zi)(zi)主(zhu)品(pin)牌擴大在(zai)政(zheng)(zheng)府采購的(de)(de)市場份額,為(wei)改變(bian)目(mu)前(qian)國內政(zheng)(zheng)府采購以合資品(pin)牌產品(pin)為(wei)主(zhu)的(de)(de)局面(mian)提(ti)供了保障(zhang)。促進自(zi)(zi)主(zhu)品(pin)牌發展(zhan),國產汽車(che)(che)(che)業(ye)(ye)的(de)(de)繁榮將為(wei)汽車(che)(che)(che)膠(jiao)的(de)(de)應用(yong)(yong)提(ti)供有力保障(zhang)。預(yu)測未來3年,我國室溫硫化硅(gui)(gui)橡膠(jiao)在(zai)汽車(che)(che)(che)行業(ye)(ye)將以年均20%增(zeng)長。
此(ci)外(wai),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)是重要的(de)(de)非(fei)石(shi)(shi)油(you)(you)基合成橡(xiang)(xiang)膠(jiao),約占非(fei)石(shi)(shi)油(you)(you)基合成橡(xiang)(xiang)膠(jiao)消(xiao)費量的(de)(de)98%。但因(yin)為(wei)石(shi)(shi)油(you)(you)價格的(de)(de)大幅(fu)上(shang)漲(zhang),同(tong)時我(wo)國(guo)在硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)關(guan)鍵原料有(you)(you)機(ji)硅(gui)(gui)單體的(de)(de)生產技術方面取(qu)得突(tu)破,有(you)(you)機(ji)硅(gui)(gui)單體的(de)(de)生產技術在2005年前被幾家跨國(guo)公(gong)司(si)壟斷,但目(mu)前我(wo)國(guo)已發展成為(wei)全(quan)球有(you)(you)機(ji)硅(gui)(gui)單體第1大國(guo),這(zhe)2個方面原因(yin)使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)價格從2011年起開始低于石(shi)(shi)油(you)(you)基合成橡(xiang)(xiang)膠(jiao),僅約為(wei)大宗石(shi)(shi)油(you)(you)基橡(xiang)(xiang)膠(jiao)的(de)(de)80%~90%,成為(wei)廉價的(de)(de)合成橡(xiang)(xiang)膠(jiao),并開始大規模(mo)替代石(shi)(shi)油(you)(you)基合成橡(xiang)(xiang)膠(jiao)。這(zhe)將極(ji)大拓展有(you)(you)機(ji)硅(gui)(gui)產業的(de)(de)市(shi)場(chang)空間,同(tong)時將帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)樹脂等其他(ta)有(you)(you)機(ji)硅(gui)(gui)產品的(de)(de)消(xiao)費。