硅橡膠是(shi)指主鏈(lian)由硅(gui)(gui)和(he)氧原(yuan)子交替構成(cheng),硅(gui)(gui)原(yuan)子上(shang)通常連有兩個有機基(ji)團的橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主要由含甲基(ji)和(he)少量乙烯基(ji)的硅(gui)(gui)氧鏈(lian)節組(zu)成(cheng)。苯基(ji)的引入可提高(gao)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐高(gao)、低溫(wen)性(xing)能(neng)(neng)(neng),三氟丙基(ji)及(ji)氰(qing)基(ji)的引入則可提高(gao)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐溫(wen)及(ji)耐油性(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低溫(wen)性(xing)能(neng)(neng)(neng)良好(hao),一般在(zai)-55℃下(xia)仍能(neng)(neng)(neng)工(gong)作。引入苯基(ji)后,可達(da)-73℃。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐熱性(xing)能(neng)(neng)(neng)也(ye)很突出(chu)(chu),在(zai)180℃下(xia)可長期(qi)工(gong)作,稍(shao)高(gao)于200℃也(ye)能(neng)(neng)(neng)承受(shou)數周或更(geng)長時間仍有彈性(xing),瞬時可耐300℃以上(shang)的高(gao)溫(wen)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的透氣(qi)性(xing)好(hao),氧氣(qi)透過率在(zai)合成(cheng)聚合物中是(shi)較(jiao)高(gao)的。此外(wai),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有生理惰性(xing)、不會(hui)導致凝血的突出(chu)(chu)特性(xing),因(yin)此在(zai)醫用(yong)領域(yu)應用(yong)廣(guang)泛。
主要品種
硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類的(de)(de)方法很(hen)多,通(tong)常按固(gu)化前的(de)(de)形態分(fen)為(wei)固(gu)體(ti)(ti)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和液(ye)體(ti)(ti)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按硫(liu)化溫(wen)(wen)(wen)度分(fen)為(wei)室(shi)溫(wen)(wen)(wen)硫(liu)化硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高溫(wen)(wen)(wen)硫(liu)化硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按所用(yong)單體(ti)(ti)的(de)(de)不同,可分(fen)為(wei)甲(jia)基(ji)(ji)(ji)乙(yi)烯(xi)(xi)基(ji)(ji)(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲(jia)基(ji)(ji)(ji)苯基(ji)(ji)(ji)乙(yi)烯(xi)(xi)基(ji)(ji)(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟(fu)硅,腈硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng);按性能和用(yong)途的(de)(de)不同又(you)可分(fen)為(wei)通(tong)用(yong)型(xing)(xing)、超耐(nai)低溫(wen)(wen)(wen)型(xing)(xing)、超耐(nai)高溫(wen)(wen)(wen)型(xing)(xing)、高強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由美(mei)國(guo)以三氯化(hua)鐵為催化(hua)劑合成的。1945年(nian)(nian),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世。1948年(nian)(nian),采用高(gao)比表面積的氣相(xiang)法白炭黑補強的硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研制成功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的性能(neng)躍升(sheng)到實用階(jie)段,奠定了(le)現代(dai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)技術的基礎。從二甲(jia)基二氯硅(gui)(gui)(gui)烷合成開始生(sheng)(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的國(guo)家有美(mei)國(guo)。俄羅(luo)斯、德國(guo)、日本、韓國(guo)和中(zhong)(zhong)國(guo)等。中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的工業(ye)化(hua)研究始于(yu)1957年(nian)(nian),多家研究所和企(qi)業(ye)陸(lu)續開發出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底,中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)能(neng)力為135千噸(dun)(dun),其中(zhong)(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千噸(dun)(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)化(hua)(hua)硅橡(xiang)膠(jiao)是(shi)(shi)指(zhi)聚硅氧(yang)(yang)烷(wan)變成彈(dan)性(xing)體的(de)過(guo)程(cheng)是(shi)(shi)經過(guo)高(gao)溫(110-170℃)硫(liu)(liu)化(hua)(hua)成型的(de)。它主(zhu)要以高(gao)分子(zi)量的(de)聚甲基乙烯基硅氧(yang)(yang)烷(wan)為(wei)生膠(jiao),混入補強(qiang)填料、硫(liu)(liu)化(hua)(hua)劑等,在加熱加壓(ya)下硫(liu)(liu)化(hua)(hua)成彈(dan)性(xing)體。硅橡(xiang)膠(jiao)的(de)補強(qiang)主(zhu)要是(shi)(shi)各(ge)種(zhong)類型的(de)白炭黑(hei),可使(shi)硫(liu)(liu)化(hua)(hua)膠(jiao)的(de)強(qiang)度增(zeng)加數十(shi)倍。有時為(wei)了降低成本或改(gai)善膠(jiao)料性(xing)能(neng)及(ji)賦予硫(liu)(liu)化(hua)(hua)膠(jiao)各(ge)種(zhong)特殊的(de)性(xing)能(neng),也(ye)加入相(xiang)應(ying)(ying)的(de)各(ge)種(zhong)添加劑。硫(liu)(liu)化(hua)(hua)劑是(shi)(shi)各(ge)種(zhong)有機過(guo)氧(yang)(yang)化(hua)(hua)物或加成反應(ying)(ying)催化(hua)(hua)劑。
加工成型方法如(ru)圖所(suo)示。一次硫化(hua)的目(mu)的是進(jin)行高分(fen)子鏈的交聯(lian)反應;二(er)次硫化(hua)的目(mu)的是進(jin)行補充交聯(lian)、驅(qu)除(chu)硫化(hua)劑分(fen)解產物和其他(ta)揮發性化(hua)合物以(yi)穩定(ding)硫化(hua)膠的各(ge)項性能(neng)。常用的設備(bei)有開放式煉膠機(ji)、捏合機(ji)及真空(kong)密煉機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)(de)特征(zheng)是高溫(wen)(wen)(wen)穩定性(xing)(xing)(xing),雖然(ran)(ran)常(chang)溫(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)強度僅(jin)是天(tian)然(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)(yi)半,但在(zai)200℃以(yi)上的(de)(de)(de)高溫(wen)(wen)(wen)環境下(xia)(xia),硅橡(xiang)膠(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)保持(chi)一(yi)(yi)定的(de)(de)(de)柔(rou)韌(ren)性(xing)(xing)(xing)、回彈性(xing)(xing)(xing)和(he)(he)表面硬度,且(qie)力學(xue)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)(wu)明(ming)顯變化。(2)低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)度一(yi)(yi)般(ban)為-70~-50℃,特殊配方可(ke)達-100℃,表明(ming)其(qi)低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)(you)異。這對(dui)(dui)航空(kong)、宇航工(gong)業的(de)(de)(de)意義重大。(3)耐(nai)(nai)(nai)候(hou)性(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)(dui)氧(yang)、臭氧(yang)及紫外(wai)線等十分穩定,在(zai)不加任何添加劑的(de)(de)(de)情況下(xia)(xia),就(jiu)具有優(you)(you)良的(de)(de)(de)耐(nai)(nai)(nai)候(hou)性(xing)(xing)(xing)。(4)電(dian)(dian)氣(qi)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)具有優(you)(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)(nai)電(dian)(dian)暈性(xing)(xing)(xing)和(he)(he)耐(nai)(nai)(nai)電(dian)(dian)弧性(xing)(xing)(xing)也非常(chang)好。(5)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比(bi)通用橡(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)高溫(wen)(wen)(wen)和(he)(he)-50℃的(de)(de)(de)低(di)(di)溫(wen)(wen)(wen)下(xia)(xia),其(qi)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)(you)于通用橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油(you)及化學(xue)試劑性(xing)(xing)(xing)。普通硅橡(xiang)膠(jiao)(jiao)(jiao)具有中等的(de)(de)(de)耐(nai)(nai)(nai)油(you)、耐(nai)(nai)(nai)溶劑性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)對(dui)(dui)空(kong)氣(qi)、氮、氧(yang)、二(er)氧(yang)化碳等氣(qi)體的(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)比(bi)天(tian)然(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)高出30-50倍。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅,與人體組織不粘連,具有抗凝血作用,對(dui)(dui)肌體組織的(de)(de)(de)反(fan)應性(xing)(xing)(xing)非常(chang)少。特別適合作為醫用材(cai)料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)車(che)工業協會統計(ji),2012年,汽(qi)(qi)車(che)產銷分別(bie)達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)工業硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)用(yong)(yong)(yong)量約達2.0萬(wan)t。根據觀研天(tian)下的(de)(de)(de)(de)新研究(jiu),增(zeng)加(jia)有機硅(gui)材料在(zai)汽(qi)(qi)車(che)零(ling)部件方面的(de)(de)(de)(de)用(yong)(yong)(yong)量,可(ke)以(yi)大幅度(du)(du)提高汽(qi)(qi)車(che)的(de)(de)(de)(de)安全性(xing)能(neng),因(yin)此(ci),汽(qi)(qi)車(che)產量和單車(che)用(yong)(yong)(yong)量水平的(de)(de)(de)(de)提高都將推(tui)動(dong)汽(qi)(qi)車(che)工業對硅(gui)橡(xiang)膠(jiao)(jiao)需求(qiu)的(de)(de)(de)(de)增(zeng)加(jia)。國(guo)(guo)家(jia)鼓勵自(zi)主(zhu)品(pin)牌(pai)的(de)(de)(de)(de)汽(qi)(qi)車(che)發展,關(guan)鍵汽(qi)(qi)車(che)零(ling)部件實現(xian)自(zi)主(zhu)化,《2012年度(du)(du)黨政機關(guan)公務用(yong)(yong)(yong)車(che)選用(yong)(yong)(yong)車(che)型目(mu)(mu)錄(征求(qiu)意見(jian)稿)》為(wei)(wei)自(zi)主(zhu)品(pin)牌(pai)擴大在(zai)政府(fu)采購的(de)(de)(de)(de)市場份額,為(wei)(wei)改變目(mu)(mu)前(qian)國(guo)(guo)內政府(fu)采購以(yi)合資品(pin)牌(pai)產品(pin)為(wei)(wei)主(zhu)的(de)(de)(de)(de)局面提供了(le)保障。促進自(zi)主(zhu)品(pin)牌(pai)發展,國(guo)(guo)產汽(qi)(qi)車(che)業的(de)(de)(de)(de)繁榮(rong)將為(wei)(wei)汽(qi)(qi)車(che)膠(jiao)(jiao)的(de)(de)(de)(de)應用(yong)(yong)(yong)提供有力保障。預測(ce)未來3年,我(wo)國(guo)(guo)室溫硫化硅(gui)橡(xiang)膠(jiao)(jiao)在(zai)汽(qi)(qi)車(che)行業將以(yi)年均20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)是重要的(de)(de)非石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),約占非石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)消費量(liang)的(de)(de)98%。但因為(wei)石(shi)(shi)油(you)價格的(de)(de)大(da)幅(fu)上漲,同時我國(guo)在硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)關鍵原料有機(ji)硅(gui)(gui)單體(ti)的(de)(de)生產(chan)技術方(fang)面(mian)取得(de)突破,有機(ji)硅(gui)(gui)單體(ti)的(de)(de)生產(chan)技術在2005年(nian)前被(bei)幾家跨國(guo)公(gong)司壟(long)斷,但目(mu)前我國(guo)已發(fa)展(zhan)成(cheng)為(wei)全(quan)球有機(ji)硅(gui)(gui)單體(ti)第(di)1大(da)國(guo),這2個方(fang)面(mian)原因使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)價格從(cong)2011年(nian)起開始(shi)低于石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),僅約為(wei)大(da)宗石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為(wei)廉價的(de)(de)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),并開始(shi)大(da)規模替代石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。這將極(ji)大(da)拓展(zhan)有機(ji)硅(gui)(gui)產(chan)業的(de)(de)市場(chang)空間,同時將帶動硅(gui)(gui)油(you)、硅(gui)(gui)烷偶聯(lian)劑和硅(gui)(gui)樹脂等其他(ta)有機(ji)硅(gui)(gui)產(chan)品的(de)(de)消費。