硅橡膠是(shi)(shi)指主(zhu)鏈由(you)硅(gui)(gui)(gui)和(he)氧(yang)原子(zi)交替構成,硅(gui)(gui)(gui)原子(zi)上通常連有兩個有機(ji)基(ji)(ji)團(tuan)的(de)(de)橡(xiang)(xiang)膠。普通的(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠主(zhu)要由(you)含甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)(de)硅(gui)(gui)(gui)氧(yang)鏈節(jie)組成。苯基(ji)(ji)的(de)(de)引入可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)(nai)高(gao)、低溫性(xing)能(neng)(neng)(neng),三氟(fu)丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)(nai)溫及耐(nai)(nai)油性(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠耐(nai)(nai)低溫性(xing)能(neng)(neng)(neng)良好,一(yi)般在(zai)-55℃下(xia)仍能(neng)(neng)(neng)工作。引入苯基(ji)(ji)后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)(nai)熱性(xing)能(neng)(neng)(neng)也很突(tu)出(chu),在(zai)180℃下(xia)可(ke)長期工作,稍高(gao)于200℃也能(neng)(neng)(neng)承受(shou)數周或更長時(shi)間仍有彈性(xing),瞬(shun)時(shi)可(ke)耐(nai)(nai)300℃以上的(de)(de)高(gao)溫。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)透氣性(xing)好,氧(yang)氣透過(guo)率在(zai)合成聚合物中是(shi)(shi)較高(gao)的(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠還具有生理惰性(xing)、不會導致凝血的(de)(de)突(tu)出(chu)特性(xing),因此在(zai)醫用領域應(ying)用廣泛(fan)。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)分(fen)(fen)類的(de)方法很多,通(tong)常按固化(hua)(hua)前的(de)形態(tai)分(fen)(fen)為(wei)(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao);按硫化(hua)(hua)溫(wen)(wen)度分(fen)(fen)為(wei)(wei)室溫(wen)(wen)硫化(hua)(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao),高溫(wen)(wen)硫化(hua)(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao);按所用(yong)單(dan)體的(de)不(bu)同(tong),可(ke)分(fen)(fen)為(wei)(wei)甲基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)等(deng);按性能和用(yong)途(tu)的(de)不(bu)同(tong)又可(ke)分(fen)(fen)為(wei)(wei)通(tong)用(yong)型(xing)(xing)、超(chao)耐(nai)低(di)溫(wen)(wen)型(xing)(xing)、超(chao)耐(nai)高溫(wen)(wen)型(xing)(xing)、高強(qiang)力(li)型(xing)(xing)、耐(nai)油(you)型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)膠早期(qi)是由美國(guo)(guo)以三氯化(hua)鐵為催化(hua)劑合成(cheng)(cheng)的(de)(de)。1945年,硅(gui)橡(xiang)膠產品問世。1948年,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)膠研(yan)制成(cheng)(cheng)功,使硅(gui)橡(xiang)膠的(de)(de)性能(neng)(neng)躍升到(dao)實用階段,奠定了現代硅(gui)橡(xiang)膠生(sheng)產技術的(de)(de)基礎。從二甲基二氯硅(gui)烷合成(cheng)(cheng)開始生(sheng)產硅(gui)橡(xiang)膠的(de)(de)國(guo)(guo)家(jia)有美國(guo)(guo)。俄羅斯、德國(guo)(guo)、日(ri)本、韓(han)國(guo)(guo)和(he)(he)中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)膠的(de)(de)工業化(hua)研(yan)究始于1957年,多家(jia)研(yan)究所和(he)(he)企業陸(lu)續開發出各(ge)種(zhong)硅(gui)橡(xiang)膠。到(dao)2003年底,中(zhong)國(guo)(guo)硅(gui)橡(xiang)膠生(sheng)產能(neng)(neng)力為135千噸(dun),其中(zhong)高溫膠100千噸(dun)。
高溫硫化硅橡膠
高(gao)(gao)溫硫(liu)化(hua)(hua)(hua)硅橡(xiang)膠是指(zhi)聚硅氧烷變成彈性體的過程是經過高(gao)(gao)溫(110-170℃)硫(liu)化(hua)(hua)(hua)成型(xing)的。它主(zhu)要(yao)以高(gao)(gao)分子量的聚甲(jia)基(ji)乙烯基(ji)硅氧烷為生膠,混入補(bu)強填(tian)料、硫(liu)化(hua)(hua)(hua)劑(ji)(ji)(ji)等,在加熱加壓下硫(liu)化(hua)(hua)(hua)成彈性體。硅橡(xiang)膠的補(bu)強主(zhu)要(yao)是各(ge)種(zhong)(zhong)類型(xing)的白炭黑,可使硫(liu)化(hua)(hua)(hua)膠的強度增加數十倍。有(you)(you)時(shi)為了降低成本或改(gai)善膠料性能(neng)及賦予硫(liu)化(hua)(hua)(hua)膠各(ge)種(zhong)(zhong)特殊的性能(neng),也加入相應的各(ge)種(zhong)(zhong)添加劑(ji)(ji)(ji)。硫(liu)化(hua)(hua)(hua)劑(ji)(ji)(ji)是各(ge)種(zhong)(zhong)有(you)(you)機過氧化(hua)(hua)(hua)物或加成反(fan)應催化(hua)(hua)(hua)劑(ji)(ji)(ji)。
加工(gong)成(cheng)型方(fang)法如圖所示。一(yi)次(ci)硫化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)(shi)進行高(gao)分子鏈的(de)(de)(de)交聯反(fan)應;二次(ci)硫化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)(shi)進行補(bu)充交聯、驅除(chu)硫化(hua)劑分解產物和其他揮(hui)發性(xing)化(hua)合物以穩定硫化(hua)膠的(de)(de)(de)各項性(xing)能。常用(yong)的(de)(de)(de)設備有(you)開放式(shi)煉膠機(ji)、捏(nie)合機(ji)及真(zhen)空密(mi)煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯著(zhu)的(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)下(xia)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)強(qiang)度僅是(shi)天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)一半,但(dan)在(zai)200℃以上的(de)(de)高(gao)溫(wen)(wen)環境下(xia),硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保(bao)持一定(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)玻璃(li)化(hua)溫(wen)(wen)度一般為(wei)-70~-50℃,特(te)殊配方可達-100℃,表明其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)(yi)。這對航空、宇航工業的(de)(de)意(yi)義重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)紫(zi)外(wai)線等十分穩定(ding),在(zai)不加任何添(tian)加劑(ji)(ji)的(de)(de)情況下(xia),就具(ju)(ju)有(you)(you)優(you)良的(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)優(you)異(yi)(yi)的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)常溫(wen)(wen)下(xia)的(de)(de)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)高(gao)溫(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)下(xia),其(qi)物(wu)(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于(yu)通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐油及(ji)化(hua)學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)中等的(de)(de)耐油、耐溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體(ti)(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)下(xia)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)對空氣、氮、氧(yang)、二氧(yang)化(hua)碳等氣體(ti)(ti)(ti)的(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人(ren)體(ti)(ti)(ti)組織(zhi)不粘連,具(ju)(ju)有(you)(you)抗凝血作用(yong),對肌體(ti)(ti)(ti)組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別(bie)適合作為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)(che)工業(ye)(ye)(ye)協(xie)會統(tong)計,2012年,汽(qi)(qi)(qi)車(che)(che)(che)產銷(xiao)分(fen)別(bie)達到1927.18萬輛和(he)1930.64萬輛,同比分(fen)別(bie)增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)(che)工業(ye)(ye)(ye)硅橡(xiang)(xiang)膠的(de)(de)(de)用(yong)量(liang)(liang)約達2.0萬t。根據觀研(yan)天下的(de)(de)(de)新研(yan)究(jiu),增(zeng)加有(you)機硅材料在汽(qi)(qi)(qi)車(che)(che)(che)零部件方面的(de)(de)(de)用(yong)量(liang)(liang),可以(yi)大(da)幅(fu)度提高汽(qi)(qi)(qi)車(che)(che)(che)的(de)(de)(de)安全性能,因此(ci),汽(qi)(qi)(qi)車(che)(che)(che)產量(liang)(liang)和(he)單車(che)(che)(che)用(yong)量(liang)(liang)水平的(de)(de)(de)提高都將(jiang)推動汽(qi)(qi)(qi)車(che)(che)(che)工業(ye)(ye)(ye)對(dui)硅橡(xiang)(xiang)膠需(xu)求的(de)(de)(de)增(zeng)加。國(guo)(guo)家鼓勵自主品(pin)(pin)牌的(de)(de)(de)汽(qi)(qi)(qi)車(che)(che)(che)發(fa)展,關(guan)鍵汽(qi)(qi)(qi)車(che)(che)(che)零部件實現自主化,《2012年度黨政(zheng)機關(guan)公務用(yong)車(che)(che)(che)選(xuan)用(yong)車(che)(che)(che)型目(mu)錄(征求意見稿)》為(wei)自主品(pin)(pin)牌擴大(da)在政(zheng)府(fu)采購(gou)的(de)(de)(de)市(shi)場份額,為(wei)改(gai)變目(mu)前(qian)國(guo)(guo)內(nei)政(zheng)府(fu)采購(gou)以(yi)合資品(pin)(pin)牌產品(pin)(pin)為(wei)主的(de)(de)(de)局面提供(gong)了保障。促(cu)進(jin)自主品(pin)(pin)牌發(fa)展,國(guo)(guo)產汽(qi)(qi)(qi)車(che)(che)(che)業(ye)(ye)(ye)的(de)(de)(de)繁榮將(jiang)為(wei)汽(qi)(qi)(qi)車(che)(che)(che)膠的(de)(de)(de)應用(yong)提供(gong)有(you)力保障。預測(ce)未來3年,我國(guo)(guo)室溫硫化硅橡(xiang)(xiang)膠在汽(qi)(qi)(qi)車(che)(che)(che)行業(ye)(ye)(ye)將(jiang)以(yi)年均20%增(zeng)長。
此外,硅(gui)橡膠(jiao)(jiao)是重要的非石(shi)(shi)油(you)(you)(you)基合成橡膠(jiao)(jiao),約占(zhan)非石(shi)(shi)油(you)(you)(you)基合成橡膠(jiao)(jiao)消費量的98%。但(dan)因(yin)為石(shi)(shi)油(you)(you)(you)價格(ge)的大幅上漲,同時我國(guo)(guo)(guo)在(zai)硅(gui)橡膠(jiao)(jiao)的關鍵原(yuan)料有機硅(gui)單體的生(sheng)產(chan)技(ji)術方面取得突破,有機硅(gui)單體的生(sheng)產(chan)技(ji)術在(zai)2005年前被幾家跨國(guo)(guo)(guo)公司壟斷(duan),但(dan)目前我國(guo)(guo)(guo)已發(fa)展(zhan)(zhan)成為全球有機硅(gui)單體第1大國(guo)(guo)(guo),這2個方面原(yuan)因(yin)使硅(gui)橡膠(jiao)(jiao)的價格(ge)從(cong)2011年起(qi)開(kai)始(shi)低(di)于石(shi)(shi)油(you)(you)(you)基合成橡膠(jiao)(jiao),僅約為大宗石(shi)(shi)油(you)(you)(you)基橡膠(jiao)(jiao)的80%~90%,成為廉價的合成橡膠(jiao)(jiao),并(bing)開(kai)始(shi)大規模替代石(shi)(shi)油(you)(you)(you)基合成橡膠(jiao)(jiao)。這將極大拓展(zhan)(zhan)有機硅(gui)產(chan)業的市場(chang)空(kong)間,同時將帶動(dong)硅(gui)油(you)(you)(you)、硅(gui)烷偶(ou)聯劑和硅(gui)樹脂(zhi)等其他(ta)有機硅(gui)產(chan)品的消費。