硅橡膠是(shi)指主鏈由(you)(you)硅(gui)(gui)(gui)和氧(yang)原子交替構成,硅(gui)(gui)(gui)原子上(shang)通(tong)常連有兩(liang)個(ge)有機基(ji)(ji)團的(de)橡(xiang)(xiang)膠。普通(tong)的(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠主要由(you)(you)含甲(jia)基(ji)(ji)和少(shao)量乙烯基(ji)(ji)的(de)硅(gui)(gui)(gui)氧(yang)鏈節組(zu)成。苯基(ji)(ji)的(de)引入(ru)可(ke)提(ti)高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)耐高(gao)、低(di)溫(wen)性(xing)(xing)(xing)能,三氟丙(bing)基(ji)(ji)及(ji)氰(qing)基(ji)(ji)的(de)引入(ru)則可(ke)提(ti)高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)耐溫(wen)及(ji)耐油性(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)(xiang)膠耐低(di)溫(wen)性(xing)(xing)(xing)能良好,一般在(zai)-55℃下(xia)仍能工(gong)作。引入(ru)苯基(ji)(ji)后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)耐熱性(xing)(xing)(xing)能也(ye)(ye)很(hen)突(tu)(tu)出,在(zai)180℃下(xia)可(ke)長期(qi)工(gong)作,稍高(gao)于200℃也(ye)(ye)能承受數周或(huo)更長時間仍有彈性(xing)(xing)(xing),瞬時可(ke)耐300℃以上(shang)的(de)高(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)透氣性(xing)(xing)(xing)好,氧(yang)氣透過率在(zai)合成聚(ju)合物中(zhong)是(shi)較高(gao)的(de)。此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠還具有生理惰性(xing)(xing)(xing)、不會導(dao)致(zhi)凝血的(de)突(tu)(tu)出特性(xing)(xing)(xing),因此在(zai)醫(yi)用領域(yu)應用廣(guang)泛。
主要品種
硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類的方法很(hen)多,通常按固(gu)化(hua)前的形態分(fen)為固(gu)體硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)和液體硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao);按硫化(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao),高溫(wen)硫化(hua)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao);按所(suo)用單(dan)體的不同(tong),可分(fen)為甲基乙烯(xi)基硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao),甲基苯基乙烯(xi)基硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅,腈硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng);按性能和用途的不同(tong)又可分(fen)為通用型、超耐(nai)低溫(wen)型、超耐(nai)高溫(wen)型、高強力(li)型、耐(nai)油型、醫用型等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由美(mei)國(guo)以三氯化鐵為催(cui)化劑合成(cheng)(cheng)的(de)。1945年,硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產品問世(shi)。1948年,采用高比表面積的(de)氣(qi)相法白炭黑補強的(de)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成(cheng)(cheng)功,使硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍(yue)升(sheng)到(dao)實用階段,奠定了現代(dai)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)(sheng)產技(ji)術的(de)基礎。從二(er)甲基二(er)氯硅(gui)烷(wan)合成(cheng)(cheng)開始生(sheng)(sheng)(sheng)產硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)家有美(mei)國(guo)。俄羅斯、德國(guo)、日本(ben)、韓國(guo)和中國(guo)等(deng)。中國(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)工(gong)業化研究始于1957年,多家研究所(suo)和企業陸續開發出各種硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年底,中國(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)(sheng)產能(neng)力為135千噸,其中高溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)(hua)(hua)硅(gui)橡膠是指聚硅(gui)氧(yang)(yang)烷變成彈(dan)性(xing)(xing)體的(de)(de)過程(cheng)是經過高溫(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)(hua)成型的(de)(de)。它主(zhu)要以高分(fen)子量的(de)(de)聚甲基(ji)乙烯(xi)基(ji)硅(gui)氧(yang)(yang)烷為生膠,混(hun)入補強填(tian)料、硫(liu)(liu)化(hua)(hua)(hua)(hua)劑等,在加熱加壓下硫(liu)(liu)化(hua)(hua)(hua)(hua)成彈(dan)性(xing)(xing)體。硅(gui)橡膠的(de)(de)補強主(zhu)要是各(ge)種類型的(de)(de)白(bai)炭黑,可使硫(liu)(liu)化(hua)(hua)(hua)(hua)膠的(de)(de)強度增加數十(shi)倍。有時(shi)為了降低成本或改善膠料性(xing)(xing)能及賦(fu)予硫(liu)(liu)化(hua)(hua)(hua)(hua)膠各(ge)種特殊(shu)的(de)(de)性(xing)(xing)能,也加入相應(ying)的(de)(de)各(ge)種添加劑。硫(liu)(liu)化(hua)(hua)(hua)(hua)劑是各(ge)種有機過氧(yang)(yang)化(hua)(hua)(hua)(hua)物或加成反(fan)應(ying)催化(hua)(hua)(hua)(hua)劑。
加工(gong)成型(xing)方(fang)法如圖(tu)所示。一次硫(liu)化(hua)(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)高(gao)分(fen)子鏈的(de)(de)(de)交(jiao)聯反應;二(er)次硫(liu)化(hua)(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)補(bu)充交(jiao)聯、驅除(chu)硫(liu)化(hua)(hua)(hua)劑(ji)分(fen)解產物(wu)和其(qi)他揮發(fa)性化(hua)(hua)(hua)合(he)(he)物(wu)以穩定(ding)硫(liu)化(hua)(hua)(hua)膠的(de)(de)(de)各項性能。常用的(de)(de)(de)設(she)備(bei)有(you)開放式(shi)煉膠機(ji)、捏合(he)(he)機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)強度僅是(shi)天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)或(huo)某些(xie)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)一(yi)半,但在200℃以上的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下(xia)(xia)(xia),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持一(yi)定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度,且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)(wu)明顯(xian)變化。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度一(yi)般為(wei)-70~-50℃,特(te)殊(shu)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)(neng)(neng)(neng)優異(yi)。這對(dui)(dui)航(hang)空、宇航(hang)工(gong)業的(de)(de)意義重大。(3)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)(dui)氧、臭氧及紫外線等(deng)十(shi)分穩定,在不加任何添加劑的(de)(de)情況下(xia)(xia)(xia),就具有(you)優良的(de)(de)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)具有(you)優異(yi)的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)的(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)低(di)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia),其物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通(tong)用(yong)(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油及化學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)具有(you)中(zhong)等(deng)的(de)(de)耐(nai)(nai)(nai)油、耐(nai)(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室(shi)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)對(dui)(dui)空氣(qi)、氮、氧、二氧化碳等(deng)氣(qi)體的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與(yu)人體組(zu)織不粘(zhan)連,具有(you)抗凝血(xue)作(zuo)用(yong)(yong),對(dui)(dui)肌體組(zu)織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特(te)別適(shi)合作(zuo)為(wei)醫用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)汽車(che)(che)(che)工(gong)業(ye)協會(hui)統計,2012年(nian)(nian),汽車(che)(che)(che)產(chan)(chan)銷分(fen)別達(da)到1927.18萬輛和(he)1930.64萬輛,同比(bi)分(fen)別增(zeng)長4.63%和(he)4.33%,汽車(che)(che)(che)工(gong)業(ye)硅橡膠(jiao)(jiao)的用量約(yue)達(da)2.0萬t。根據觀(guan)研天下的新研究(jiu),增(zeng)加有機硅材料在(zai)汽車(che)(che)(che)零部件(jian)方面的用量,可以大(da)幅度(du)提(ti)高(gao)汽車(che)(che)(che)的安(an)全性(xing)能,因此,汽車(che)(che)(che)產(chan)(chan)量和(he)單車(che)(che)(che)用量水平(ping)的提(ti)高(gao)都將推(tui)動(dong)汽車(che)(che)(che)工(gong)業(ye)對硅橡膠(jiao)(jiao)需求的增(zeng)加。國(guo)家(jia)鼓勵自主(zhu)品(pin)牌(pai)(pai)的汽車(che)(che)(che)發展(zhan),關(guan)鍵(jian)汽車(che)(che)(che)零部件(jian)實(shi)現自主(zhu)化,《2012年(nian)(nian)度(du)黨政機關(guan)公務用車(che)(che)(che)選用車(che)(che)(che)型目錄(征求意見稿)》為自主(zhu)品(pin)牌(pai)(pai)擴大(da)在(zai)政府采購(gou)的市(shi)場(chang)份額,為改變(bian)目前國(guo)內政府采購(gou)以合(he)資品(pin)牌(pai)(pai)產(chan)(chan)品(pin)為主(zhu)的局面提(ti)供了(le)保障(zhang)(zhang)。促進自主(zhu)品(pin)牌(pai)(pai)發展(zhan),國(guo)產(chan)(chan)汽車(che)(che)(che)業(ye)的繁榮將為汽車(che)(che)(che)膠(jiao)(jiao)的應用提(ti)供有力(li)保障(zhang)(zhang)。預(yu)測未(wei)來3年(nian)(nian),我國(guo)室溫硫化硅橡膠(jiao)(jiao)在(zai)汽車(che)(che)(che)行(xing)業(ye)將以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)橡(xiang)膠(jiao)是重要(yao)的(de)(de)(de)非(fei)石油基(ji)合成(cheng)(cheng)(cheng)橡(xiang)膠(jiao),約(yue)占非(fei)石油基(ji)合成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)消(xiao)費量的(de)(de)(de)98%。但(dan)因為石油價(jia)格(ge)的(de)(de)(de)大(da)(da)幅上漲,同(tong)時我(wo)國(guo)在硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)關鍵原(yuan)料有機(ji)硅(gui)單(dan)體(ti)的(de)(de)(de)生產(chan)技術方面取得突破(po),有機(ji)硅(gui)單(dan)體(ti)的(de)(de)(de)生產(chan)技術在2005年(nian)前被幾家(jia)跨國(guo)公司(si)壟(long)斷,但(dan)目(mu)前我(wo)國(guo)已發展(zhan)成(cheng)(cheng)(cheng)為全球有機(ji)硅(gui)單(dan)體(ti)第1大(da)(da)國(guo),這2個(ge)方面原(yuan)因使(shi)硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)價(jia)格(ge)從2011年(nian)起開始低于石油基(ji)合成(cheng)(cheng)(cheng)橡(xiang)膠(jiao),僅約(yue)為大(da)(da)宗(zong)石油基(ji)橡(xiang)膠(jiao)的(de)(de)(de)80%~90%,成(cheng)(cheng)(cheng)為廉價(jia)的(de)(de)(de)合成(cheng)(cheng)(cheng)橡(xiang)膠(jiao),并開始大(da)(da)規(gui)模(mo)替代石油基(ji)合成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)。這將極大(da)(da)拓展(zhan)有機(ji)硅(gui)產(chan)業的(de)(de)(de)市場空間,同(tong)時將帶動硅(gui)油、硅(gui)烷(wan)偶聯(lian)劑(ji)和硅(gui)樹(shu)脂(zhi)等其(qi)他(ta)有機(ji)硅(gui)產(chan)品的(de)(de)(de)消(xiao)費。