
硅橡膠是(shi)指主鏈(lian)由硅(gui)(gui)(gui)和(he)氧(yang)(yang)原子(zi)交替構(gou)成,硅(gui)(gui)(gui)原子(zi)上(shang)通常連(lian)有(you)兩個(ge)有(you)機(ji)基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)(xiang)膠(jiao)。普(pu)通的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)主要由含(han)甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧(yang)(yang)鏈(lian)節組成。苯基(ji)(ji)的(de)(de)(de)引入可提高硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)耐高、低溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)(ji)及氰(qing)基(ji)(ji)的(de)(de)(de)引入則可提高硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)耐溫(wen)及耐油性(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)耐低溫(wen)性(xing)能(neng)(neng)良好(hao),一(yi)般在(zai)(zai)-55℃下仍(reng)能(neng)(neng)工作。引入苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)耐熱性(xing)能(neng)(neng)也(ye)很突(tu)(tu)出(chu),在(zai)(zai)180℃下可長期工作,稍高于200℃也(ye)能(neng)(neng)承(cheng)受數周或更長時間仍(reng)有(you)彈性(xing),瞬時可耐300℃以上(shang)的(de)(de)(de)高溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)透(tou)氣(qi)(qi)性(xing)好(hao),氧(yang)(yang)氣(qi)(qi)透(tou)過率在(zai)(zai)合成聚(ju)合物中是(shi)較高的(de)(de)(de)。此(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)還具有(you)生理惰性(xing)、不會導致凝(ning)血的(de)(de)(de)突(tu)(tu)出(chu)特性(xing),因(yin)此(ci)在(zai)(zai)醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)(gui)橡膠(jiao)分(fen)(fen)類(lei)的(de)方法(fa)很多,通常按固(gu)化(hua)前的(de)形態(tai)分(fen)(fen)為固(gu)體(ti)硅(gui)(gui)(gui)橡膠(jiao)和液體(ti)硅(gui)(gui)(gui)橡膠(jiao);按硫(liu)化(hua)溫(wen)(wen)度(du)分(fen)(fen)為室溫(wen)(wen)硫(liu)化(hua)硅(gui)(gui)(gui)橡膠(jiao),高(gao)溫(wen)(wen)硫(liu)化(hua)硅(gui)(gui)(gui)橡膠(jiao);按所用(yong)單(dan)體(ti)的(de)不同,可(ke)分(fen)(fen)為甲基乙(yi)烯(xi)基硅(gui)(gui)(gui)橡膠(jiao),甲基苯基乙(yi)烯(xi)基硅(gui)(gui)(gui)橡膠(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡膠(jiao)等;按性能和用(yong)途的(de)不同又(you)可(ke)分(fen)(fen)為通用(yong)型(xing)(xing)(xing)、超耐(nai)低溫(wen)(wen)型(xing)(xing)(xing)、超耐(nai)高(gao)溫(wen)(wen)型(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)、耐(nai)油型(xing)(xing)(xing)、醫用(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)早期(qi)是由美國(guo)以三氯(lv)化鐵(tie)為催(cui)化劑(ji)合成(cheng)的。1945年(nian),硅(gui)(gui)(gui)橡(xiang)膠(jiao)產(chan)品(pin)問世。1948年(nian),采用高比表面積(ji)的氣(qi)相法白(bai)炭黑補強的硅(gui)(gui)(gui)橡(xiang)膠(jiao)研制成(cheng)功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)的性(xing)能(neng)躍升到實用階(jie)段,奠定了現代硅(gui)(gui)(gui)橡(xiang)膠(jiao)生(sheng)(sheng)產(chan)技術的基(ji)礎(chu)。從二甲(jia)基(ji)二氯(lv)硅(gui)(gui)(gui)烷(wan)合成(cheng)開(kai)始生(sheng)(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本(ben)、韓國(guo)和(he)中(zhong)(zhong)國(guo)等(deng)。中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的工業化研究(jiu)始于1957年(nian),多家研究(jiu)所和(he)企(qi)業陸續(xu)開(kai)發(fa)出各(ge)種硅(gui)(gui)(gui)橡(xiang)膠(jiao)。到2003年(nian)底(di),中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)生(sheng)(sheng)產(chan)能(neng)力為135千噸(dun),其中(zhong)(zhong)高溫膠(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)化(hua)(hua)硅橡膠(jiao)(jiao)是指聚硅氧烷變成(cheng)(cheng)(cheng)彈(dan)性體的(de)過(guo)程(cheng)是經過(guo)高(gao)溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)(cheng)型(xing)的(de)。它主要(yao)以高(gao)分(fen)子量(liang)的(de)聚甲基(ji)乙烯基(ji)硅氧烷為生膠(jiao)(jiao),混入補強(qiang)填料、硫(liu)(liu)化(hua)(hua)劑等,在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)(cheng)彈(dan)性體。硅橡膠(jiao)(jiao)的(de)補強(qiang)主要(yao)是各種類型(xing)的(de)白炭(tan)黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)的(de)強(qiang)度增加(jia)數十(shi)倍。有時為了(le)降低成(cheng)(cheng)(cheng)本或(huo)改(gai)善膠(jiao)(jiao)料性能及賦(fu)予硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)各種特殊的(de)性能,也加(jia)入相(xiang)應的(de)各種添(tian)加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是各種有機過(guo)氧化(hua)(hua)物或(huo)加(jia)成(cheng)(cheng)(cheng)反應催化(hua)(hua)劑。
加工成型方法(fa)如圖所示。一次硫(liu)化(hua)(hua)(hua)的(de)(de)(de)(de)目的(de)(de)(de)(de)是進行(xing)高分(fen)子(zi)鏈的(de)(de)(de)(de)交(jiao)聯反應;二次硫(liu)化(hua)(hua)(hua)的(de)(de)(de)(de)目的(de)(de)(de)(de)是進行(xing)補充交(jiao)聯、驅(qu)除硫(liu)化(hua)(hua)(hua)劑分(fen)解產物(wu)和其他揮(hui)發性化(hua)(hua)(hua)合(he)物(wu)以(yi)穩定(ding)硫(liu)化(hua)(hua)(hua)膠的(de)(de)(de)(de)各項(xiang)性能。常(chang)用(yong)的(de)(de)(de)(de)設備(bei)有開放式煉膠機(ji)、捏合(he)機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著(zhu)的特(te)征是高(gao)溫(wen)穩(wen)定(ding)(ding)性(xing)(xing)(xing),雖然常(chang)溫(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的強度(du)僅是天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或(huo)某(mou)些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的一(yi)半(ban),但在200℃以上的高(gao)溫(wen)環境下(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一(yi)定(ding)(ding)的柔(rou)韌(ren)性(xing)(xing)(xing)、回彈性(xing)(xing)(xing)和表面硬(ying)度(du),且(qie)力學(xue)(xue)性(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化。(2)低溫(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的玻(bo)璃化溫(wen)度(du)一(yi)般為-70~-50℃,特(te)殊配方可達-100℃,表明其(qi)(qi)低溫(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這(zhe)對(dui)航空、宇航工業(ye)的意義重大。(3)耐候性(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)氧、臭氧及紫(zi)外線等(deng)十分(fen)穩(wen)定(ding)(ding),在不加任(ren)何添加劑(ji)的情況下(xia),就具有(you)優(you)良的耐候性(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)優(you)異的絕緣(yuan)性(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)和耐電(dian)弧性(xing)(xing)(xing)也(ye)非常(chang)好。(5)物理機械性(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)下(xia)的物理機械性(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的高(gao)溫(wen)和-50℃的低溫(wen)下(xia),其(qi)(qi)物理機械性(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐油及化學(xue)(xue)試劑(ji)性(xing)(xing)(xing)。普通(tong)(tong)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)中(zhong)等(deng)的耐油、耐溶劑(ji)性(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣、氮、氧、二(er)氧化碳等(deng)氣體的透氣性(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生(sheng)理惰性(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒(du),無(wu)味,無(wu)嗅,與(yu)人體組(zu)織(zhi)不粘(zhan)連,具有(you)抗凝(ning)血(xue)作用(yong)(yong),對(dui)肌體組(zu)織(zhi)的反應性(xing)(xing)(xing)非常(chang)少(shao)。特(te)別適合作為醫用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)協會統計,2012年,汽(qi)(qi)(qi)車(che)產銷分別(bie)達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)硅橡膠(jiao)的(de)(de)用(yong)(yong)量(liang)約達2.0萬(wan)t。根據觀(guan)研天下的(de)(de)新研究,增(zeng)加有機(ji)硅材(cai)料在汽(qi)(qi)(qi)車(che)零部(bu)件(jian)方面的(de)(de)用(yong)(yong)量(liang),可以(yi)大(da)幅度提(ti)高汽(qi)(qi)(qi)車(che)的(de)(de)安全性能,因此(ci),汽(qi)(qi)(qi)車(che)產量(liang)和單車(che)用(yong)(yong)量(liang)水(shui)平的(de)(de)提(ti)高都(dou)將推動汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)對硅橡膠(jiao)需求的(de)(de)增(zeng)加。國(guo)家鼓勵自主(zhu)(zhu)品牌的(de)(de)汽(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)車(che)零部(bu)件(jian)實(shi)現自主(zhu)(zhu)化,《2012年度黨政(zheng)機(ji)關公務用(yong)(yong)車(che)選用(yong)(yong)車(che)型(xing)目錄(征求意見稿)》為(wei)自主(zhu)(zhu)品牌擴大(da)在政(zheng)府采購的(de)(de)市場份額,為(wei)改變目前(qian)國(guo)內政(zheng)府采購以(yi)合資品牌產品為(wei)主(zhu)(zhu)的(de)(de)局面提(ti)供了保障。促進(jin)自主(zhu)(zhu)品牌發展,國(guo)產汽(qi)(qi)(qi)車(che)業(ye)(ye)的(de)(de)繁榮將為(wei)汽(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)應用(yong)(yong)提(ti)供有力保障。預(yu)測未來3年,我國(guo)室溫硫化硅橡膠(jiao)在汽(qi)(qi)(qi)車(che)行業(ye)(ye)將以(yi)年均(jun)20%增(zeng)長。
此(ci)外,硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)是重(zhong)要的(de)(de)(de)非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao)消(xiao)費量(liang)的(de)(de)(de)98%。但(dan)因為(wei)(wei)石(shi)(shi)油(you)(you)價格(ge)的(de)(de)(de)大幅上漲,同時我(wo)國(guo)(guo)在(zai)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)(de)(de)關(guan)鍵原料有(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技(ji)(ji)術(shu)方面取得突破,有(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技(ji)(ji)術(shu)在(zai)2005年(nian)前被幾家跨國(guo)(guo)公(gong)司壟斷,但(dan)目(mu)前我(wo)國(guo)(guo)已發展成(cheng)為(wei)(wei)全球有(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體第1大國(guo)(guo),這2個方面原因使硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)(de)(de)價格(ge)從(cong)2011年(nian)起開始(shi)低于(yu)石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao),僅約為(wei)(wei)大宗石(shi)(shi)油(you)(you)基橡膠(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)為(wei)(wei)廉價的(de)(de)(de)合(he)成(cheng)橡膠(jiao)(jiao),并開始(shi)大規模(mo)替代(dai)石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao)。這將極大拓展有(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)業的(de)(de)(de)市場空間(jian),同時將帶動(dong)硅(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)烷偶聯(lian)劑和硅(gui)(gui)(gui)(gui)樹脂等其他(ta)有(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)品的(de)(de)(de)消(xiao)費。