硅橡膠是指主鏈由硅和氧原子(zi)交替構成,硅原子(zi)上通常連有兩個有機基(ji)(ji)團的(de)(de)橡(xiang)(xiang)(xiang)膠(jiao)。普通的(de)(de)硅橡(xiang)(xiang)(xiang)膠(jiao)主要由含甲(jia)基(ji)(ji)和少量乙烯基(ji)(ji)的(de)(de)硅氧鏈節組成。苯(ben)基(ji)(ji)的(de)(de)引(yin)(yin)入(ru)(ru)(ru)可(ke)(ke)提高硅橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐高、低(di)溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引(yin)(yin)入(ru)(ru)(ru)則(ze)可(ke)(ke)提高硅橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐溫(wen)及耐油性(xing)能(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)耐低(di)溫(wen)性(xing)能(neng)(neng)良好,一般在-55℃下仍能(neng)(neng)工(gong)作(zuo)。引(yin)(yin)入(ru)(ru)(ru)苯(ben)基(ji)(ji)后,可(ke)(ke)達-73℃。硅橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐熱性(xing)能(neng)(neng)也(ye)很突出,在180℃下可(ke)(ke)長(chang)期工(gong)作(zuo),稍高于200℃也(ye)能(neng)(neng)承(cheng)受數周(zhou)或更長(chang)時(shi)間仍有彈性(xing),瞬(shun)時(shi)可(ke)(ke)耐300℃以上的(de)(de)高溫(wen)。硅橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)透(tou)氣(qi)性(xing)好,氧氣(qi)透(tou)過(guo)率在合(he)成聚合(he)物中是較(jiao)高的(de)(de)。此(ci)外(wai),硅橡(xiang)(xiang)(xiang)膠(jiao)還具(ju)有生(sheng)理惰性(xing)、不會導致凝血的(de)(de)突出特性(xing),因(yin)此(ci)在醫用領域應(ying)用廣(guang)泛。
主要品種
硅(gui)橡(xiang)(xiang)膠分(fen)(fen)(fen)類的(de)(de)方法很(hen)多,通常按(an)固(gu)化(hua)前的(de)(de)形態分(fen)(fen)(fen)為固(gu)體硅(gui)橡(xiang)(xiang)膠和液體硅(gui)橡(xiang)(xiang)膠;按(an)硫(liu)化(hua)溫度分(fen)(fen)(fen)為室溫硫(liu)化(hua)硅(gui)橡(xiang)(xiang)膠,高溫硫(liu)化(hua)硅(gui)橡(xiang)(xiang)膠;按(an)所(suo)用(yong)單體的(de)(de)不同(tong),可分(fen)(fen)(fen)為甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠,甲基(ji)(ji)苯基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠、氟(fu)硅(gui),腈硅(gui)橡(xiang)(xiang)膠等;按(an)性能和用(yong)途的(de)(de)不同(tong)又可分(fen)(fen)(fen)為通用(yong)型(xing)、超(chao)耐低(di)溫型(xing)、超(chao)耐高溫型(xing)、高強力型(xing)、耐油型(xing)、醫用(yong)型(xing)等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)早期是由美國(guo)以三氯化鐵為催化劑(ji)合(he)成的(de)。1945年(nian)(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)產(chan)品(pin)問世。1948年(nian)(nian),采用高比表面積的(de)氣(qi)相法白炭黑補(bu)強的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)研(yan)制(zhi)成功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)性能躍升到(dao)實用階段,奠定了現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)生產(chan)技術(shu)的(de)基礎。從(cong)二甲基二氯硅(gui)(gui)烷合(he)成開始(shi)(shi)生產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)工業化研(yan)究(jiu)始(shi)(shi)于1957年(nian)(nian),多家研(yan)究(jiu)所和企業陸(lu)續開發出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。到(dao)2003年(nian)(nian)底(di),中國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)生產(chan)能力為135千噸,其中高溫膠(jiao)(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫硫化(hua)硅橡膠(jiao)是(shi)指聚(ju)硅氧(yang)烷變成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體(ti)(ti)的(de)(de)過(guo)程是(shi)經過(guo)高(gao)溫(110-170℃)硫化(hua)成(cheng)(cheng)(cheng)型(xing)的(de)(de)。它主(zhu)要以高(gao)分子量(liang)的(de)(de)聚(ju)甲基乙烯基硅氧(yang)烷為生(sheng)膠(jiao),混入補強(qiang)(qiang)填料、硫化(hua)劑(ji)(ji)等,在加(jia)(jia)(jia)熱加(jia)(jia)(jia)壓(ya)下(xia)硫化(hua)成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體(ti)(ti)。硅橡膠(jiao)的(de)(de)補強(qiang)(qiang)主(zhu)要是(shi)各(ge)(ge)種(zhong)類型(xing)的(de)(de)白(bai)炭(tan)黑(hei),可使硫化(hua)膠(jiao)的(de)(de)強(qiang)(qiang)度增加(jia)(jia)(jia)數(shu)十倍。有(you)時為了(le)降低(di)成(cheng)(cheng)(cheng)本或改善膠(jiao)料性(xing)(xing)能(neng)(neng)及賦予(yu)硫化(hua)膠(jiao)各(ge)(ge)種(zhong)特(te)殊的(de)(de)性(xing)(xing)能(neng)(neng),也加(jia)(jia)(jia)入相(xiang)應的(de)(de)各(ge)(ge)種(zhong)添加(jia)(jia)(jia)劑(ji)(ji)。硫化(hua)劑(ji)(ji)是(shi)各(ge)(ge)種(zhong)有(you)機過(guo)氧(yang)化(hua)物或加(jia)(jia)(jia)成(cheng)(cheng)(cheng)反應催化(hua)劑(ji)(ji)。
加工(gong)成型方法(fa)如(ru)圖所示。一(yi)次硫化(hua)的(de)目(mu)的(de)是進行(xing)高分(fen)子鏈的(de)交(jiao)聯反(fan)應(ying);二次硫化(hua)的(de)目(mu)的(de)是進行(xing)補充交(jiao)聯、驅除硫化(hua)劑分(fen)解產(chan)物(wu)和(he)其他揮發性(xing)化(hua)合(he)物(wu)以穩定硫化(hua)膠的(de)各項性(xing)能(neng)。常(chang)用的(de)設備有開放(fang)式煉膠機、捏合(he)機及真(zhen)空(kong)密煉機。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)特征是(shi)(shi)高溫(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)常溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)強(qiang)度(du)僅是(shi)(shi)天(tian)(tian)然(ran)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某些(xie)合成橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)一半,但在(zai)200℃以(yi)上(shang)的(de)高溫(wen)(wen)環境下(xia)(xia),硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)(neng)保持一定(ding)的(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)明(ming)顯(xian)變化。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)玻璃(li)化溫(wen)(wen)度(du)一般(ban)為-70~-50℃,特殊配方可達-100℃,表(biao)明(ming)其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)異。這對(dui)(dui)航空、宇(yu)航工業的(de)意義重大。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫外線(xian)等十分穩(wen)定(ding),在(zai)不(bu)加(jia)任何添(tian)加(jia)劑的(de)情(qing)況(kuang)下(xia)(xia),就具(ju)有優(you)良(liang)的(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有優(you)異的(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)和(he)耐電弧(hu)性(xing)(xing)(xing)(xing)(xing)也(ye)非常好。(5)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)下(xia)(xia)的(de)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比(bi)通用橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)高溫(wen)(wen)和(he)-50℃的(de)低溫(wen)(wen)下(xia)(xia),其物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)于通用橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐油及化學試劑性(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有中等的(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣體(ti)透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)(dui)空氣、氮、氧(yang)(yang)、二氧(yang)(yang)化碳等氣體(ti)的(de)透氣性(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)(tian)然(ran)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍(bei)。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)組織(zhi)不(bu)粘連,具(ju)有抗凝血作用,對(dui)(dui)肌體(ti)組織(zhi)的(de)反應性(xing)(xing)(xing)(xing)(xing)非常少(shao)。特別適(shi)合作為醫用材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)(che)(che)工業(ye)協會(hui)統(tong)計,2012年(nian),汽(qi)(qi)車(che)(che)(che)產銷分別達到1927.18萬輛和1930.64萬輛,同比分別增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)(che)(che)工業(ye)硅(gui)(gui)橡膠(jiao)的(de)(de)(de)用(yong)(yong)量(liang)約達2.0萬t。根據觀(guan)研(yan)天(tian)下的(de)(de)(de)新(xin)研(yan)究,增(zeng)加有(you)(you)機硅(gui)(gui)材料在汽(qi)(qi)車(che)(che)(che)零部件(jian)方面的(de)(de)(de)用(yong)(yong)量(liang),可以大幅度(du)提高汽(qi)(qi)車(che)(che)(che)的(de)(de)(de)安全性能,因此(ci),汽(qi)(qi)車(che)(che)(che)產量(liang)和單車(che)(che)(che)用(yong)(yong)量(liang)水平的(de)(de)(de)提高都將推動(dong)汽(qi)(qi)車(che)(che)(che)工業(ye)對(dui)硅(gui)(gui)橡膠(jiao)需求的(de)(de)(de)增(zeng)加。國(guo)家(jia)鼓勵自主(zhu)品牌(pai)(pai)的(de)(de)(de)汽(qi)(qi)車(che)(che)(che)發(fa)展(zhan),關鍵汽(qi)(qi)車(che)(che)(che)零部件(jian)實(shi)現自主(zhu)化,《2012年(nian)度(du)黨政(zheng)機關公(gong)務用(yong)(yong)車(che)(che)(che)選用(yong)(yong)車(che)(che)(che)型目錄(lu)(征求意見稿)》為(wei)自主(zhu)品牌(pai)(pai)擴大在政(zheng)府(fu)采(cai)(cai)購的(de)(de)(de)市場份額(e),為(wei)改變(bian)目前(qian)國(guo)內政(zheng)府(fu)采(cai)(cai)購以合資品牌(pai)(pai)產品為(wei)主(zhu)的(de)(de)(de)局面提供了保障。促進自主(zhu)品牌(pai)(pai)發(fa)展(zhan),國(guo)產汽(qi)(qi)車(che)(che)(che)業(ye)的(de)(de)(de)繁榮將為(wei)汽(qi)(qi)車(che)(che)(che)膠(jiao)的(de)(de)(de)應用(yong)(yong)提供有(you)(you)力保障。預測未來3年(nian),我(wo)國(guo)室溫硫化硅(gui)(gui)橡膠(jiao)在汽(qi)(qi)車(che)(che)(che)行業(ye)將以年(nian)均20%增(zeng)長。
此外(wai),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的非(fei)石(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消(xiao)費量(liang)的98%。但因(yin)為石(shi)(shi)油(you)(you)價(jia)(jia)格的大(da)幅上漲,同時(shi)我(wo)國在(zai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的關(guan)鍵原(yuan)料有機(ji)硅(gui)單(dan)體的生產技(ji)術方面取得突破,有機(ji)硅(gui)單(dan)體的生產技(ji)術在(zai)2005年(nian)前被(bei)幾家跨國公(gong)司壟斷,但目前我(wo)國已(yi)發展成(cheng)為全球(qiu)有機(ji)硅(gui)單(dan)體第1大(da)國,這2個方面原(yuan)因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的價(jia)(jia)格從2011年(nian)起(qi)開始低(di)于(yu)石(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為大(da)宗石(shi)(shi)油(you)(you)基(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的80%~90%,成(cheng)為廉價(jia)(jia)的合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始大(da)規(gui)模替代石(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)拓(tuo)展有機(ji)硅(gui)產業的市場空間(jian),同時(shi)將帶動硅(gui)油(you)(you)、硅(gui)烷(wan)偶聯劑(ji)和硅(gui)樹脂(zhi)等其他有機(ji)硅(gui)產品(pin)的消(xiao)費。