硅橡膠是(shi)指主鏈由(you)硅(gui)(gui)和氧(yang)原子(zi)交替構成,硅(gui)(gui)原子(zi)上(shang)通(tong)常連(lian)有(you)(you)兩個有(you)(you)機基(ji)(ji)(ji)團的(de)橡(xiang)膠(jiao)(jiao)(jiao)。普通(tong)的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)主要(yao)由(you)含(han)甲基(ji)(ji)(ji)和少量乙烯基(ji)(ji)(ji)的(de)硅(gui)(gui)氧(yang)鏈節(jie)組(zu)成。苯基(ji)(ji)(ji)的(de)引(yin)(yin)入可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)(nai)高(gao)(gao)、低溫性(xing)(xing)能(neng),三氟丙基(ji)(ji)(ji)及(ji)氰基(ji)(ji)(ji)的(de)引(yin)(yin)入則可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)(nai)溫及(ji)耐(nai)(nai)油性(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)耐(nai)(nai)低溫性(xing)(xing)能(neng)良(liang)好,一(yi)般在(zai)-55℃下仍(reng)能(neng)工作。引(yin)(yin)入苯基(ji)(ji)(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)(nai)熱(re)性(xing)(xing)能(neng)也很突(tu)出(chu),在(zai)180℃下可長期工作,稍高(gao)(gao)于(yu)200℃也能(neng)承受數周(zhou)或更長時(shi)間仍(reng)有(you)(you)彈性(xing)(xing),瞬(shun)時(shi)可耐(nai)(nai)300℃以上(shang)的(de)高(gao)(gao)溫。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)透(tou)氣性(xing)(xing)好,氧(yang)氣透(tou)過率在(zai)合成聚合物中(zhong)是(shi)較高(gao)(gao)的(de)。此外(wai),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)還具(ju)有(you)(you)生(sheng)理(li)惰性(xing)(xing)、不會(hui)導致凝血的(de)突(tu)出(chu)特性(xing)(xing),因此在(zai)醫用領域應用廣(guang)泛。
主要品種(zhong)
硅橡(xiang)膠(jiao)分類的方(fang)法(fa)很(hen)多,通(tong)常按固化(hua)
前的形(xing)態分(fen)為固體(ti)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液體(ti)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)硫化溫(wen)度分(fen)為室(shi)溫(wen)硫化硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高溫(wen)硫化硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)所(suo)用(yong)單體(ti)的不(bu)同(tong)(tong),可(ke)分(fen)為甲(jia)基乙(yi)烯(xi)基硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲(jia)基苯(ben)基乙(yi)烯(xi)基硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅,腈硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等(deng);按(an)性能和用(yong)途的不(bu)同(tong)(tong)又可(ke)分(fen)為通用(yong)型、超耐低(di)溫(wen)型、超耐高溫(wen)型、高強(qiang)力(li)型、耐油型、醫用(yong)型等(deng)等(deng)。
發展史(shi)
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期是由美國(guo)(guo)以三(san)氯化(hua)鐵為(wei)催化(hua)劑(ji)合成的。1945年(nian)(nian),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產(chan)(chan)(chan)品問世。1948年(nian)(nian),采用高比表面積(ji)的氣相法白炭黑補強(qiang)的硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研制成功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性能(neng)躍升到實用階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)(sheng)產(chan)(chan)(chan)技(ji)術的基(ji)礎。從二(er)甲基(ji)二(er)氯硅(gui)(gui)烷合成開始生(sheng)(sheng)產(chan)(chan)(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國(guo)(guo)家有(you)美國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)(zhong)國(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業化(hua)研究始于(yu)1957年(nian)(nian),多家研究所和企業陸續開發出各種(zhong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年(nian)(nian)底,中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)(sheng)產(chan)(chan)(chan)能(neng)力為(wei)135千(qian)噸,其中(zhong)(zhong)高溫膠(jiao)100千(qian)噸。
高溫(wen)硫化硅橡膠
高(gao)溫硫(liu)化(hua)(hua)硅橡膠是(shi)指聚硅氧烷變成(cheng)彈(dan)性(xing)體的(de)過(guo)(guo)程是(shi)經(jing)過(guo)(guo)高(gao)溫(110-170℃)硫(liu)化(hua)(hua)成(cheng)型的(de)。它主(zhu)要以(yi)高(gao)分子(zi)量的(de)聚甲基乙烯基硅氧烷為生膠,混入補強(qiang)填料(liao)(liao)、硫(liu)化(hua)(hua)劑等,在加熱(re)加壓下(xia)硫(liu)化(hua)(hua)成(cheng)彈(dan)性(xing)體。硅橡膠的(de)補強(qiang)主(zhu)要是(shi)各(ge)(ge)種類(lei)型的(de)白炭黑(hei),可使硫(liu)化(hua)(hua)膠的(de)強(qiang)度增加數十(shi)倍。有時為了降低(di)成(cheng)本(ben)或改善膠料(liao)(liao)性(xing)能及賦予硫(liu)化(hua)(hua)膠各(ge)(ge)種特殊的(de)性(xing)能,也(ye)加入相應(ying)的(de)各(ge)(ge)種添(tian)加劑。硫(liu)化(hua)(hua)劑是(shi)各(ge)(ge)種有機過(guo)(guo)氧化(hua)(hua)物或加成(cheng)反應(ying)催化(hua)(hua)劑。
加(jia)工成型方(fang)法如(ru)圖所(suo)示。一次硫(liu)化(hua)的目的是進(jin)行高分子鏈的交聯反應(ying);二次硫(liu)化(hua)的目的是進(jin)行補充(chong)交聯、驅除硫(liu)化(hua)劑分解(jie)產物(wu)和其他揮發性(xing)化(hua)合物(wu)以穩定硫(liu)化(hua)膠的各項性(xing)能。常用(yong)的設備(bei)有(you)開放式煉膠機、捏合機及(ji)真(zhen)空密煉機。
主要性(xing)能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)特(te)征是高溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)強(qiang)度僅(jin)是天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)一半,但在(zai)(zai)(zai)200℃以上的(de)(de)(de)(de)高溫(wen)(wen)(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持一定(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬(ying)度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明(ming)顯(xian)變化(hua)。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)玻(bo)璃化(hua)溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊(shu)配(pei)方可(ke)達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異(yi)。這對航空(kong)、宇航工業的(de)(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及紫外線等(deng)十分穩定(ding),在(zai)(zai)(zai)不(bu)加(jia)任(ren)何添加(jia)劑(ji)的(de)(de)(de)(de)情況下,就具(ju)(ju)有(you)優良的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)優異(yi)的(de)(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)電(dian)(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)(wen)下的(de)(de)(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通(tong)用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)(zai)(zai)150℃的(de)(de)(de)(de)高溫(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)低(di)溫(wen)(wen)(wen)下,其物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通(tong)用橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)油及化(hua)學試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)中等(deng)的(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對空(kong)氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)碳(tan)等(deng)氣(qi)體(ti)的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高出(chu)30-50倍。(8)生理惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒(du),無(wu)味,無(wu)嗅,與人(ren)體(ti)組織不(bu)粘連,具(ju)(ju)有(you)抗凝(ning)血作(zuo)用,對肌體(ti)組織的(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特(te)別適合(he)(he)作(zuo)為醫用材料(liao)。
硅橡(xiang)膠的用(yong)量
據(ju)中國(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工業(ye)(ye)協會統(tong)計,2012年,汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)產(chan)銷分別達到1927.18萬輛和(he)1930.64萬輛,同比分別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工業(ye)(ye)硅(gui)(gui)橡膠的(de)(de)(de)用(yong)量(liang)約達2.0萬t。根(gen)據(ju)觀研天下(xia)的(de)(de)(de)新研究,增(zeng)加(jia)有機(ji)硅(gui)(gui)材料在汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部(bu)件(jian)方面的(de)(de)(de)用(yong)量(liang),可以(yi)大幅度提(ti)(ti)高汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)的(de)(de)(de)安(an)全性能,因此,汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)產(chan)量(liang)和(he)單車(che)(che)(che)(che)用(yong)量(liang)水平的(de)(de)(de)提(ti)(ti)高都將推動汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工業(ye)(ye)對硅(gui)(gui)橡膠需求(qiu)的(de)(de)(de)增(zeng)加(jia)。國(guo)(guo)家鼓勵自(zi)主品(pin)牌的(de)(de)(de)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)發展,關鍵(jian)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部(bu)件(jian)實現(xian)自(zi)主化,《2012年度黨(dang)政(zheng)機(ji)關公務用(yong)車(che)(che)(che)(che)選(xuan)用(yong)車(che)(che)(che)(che)型目錄(征求(qiu)意見稿)》為自(zi)主品(pin)牌擴大在政(zheng)府采購(gou)的(de)(de)(de)市場份額,為改變(bian)目前國(guo)(guo)內政(zheng)府采購(gou)以(yi)合資品(pin)牌產(chan)品(pin)為主的(de)(de)(de)局面提(ti)(ti)供了保障。促進自(zi)主品(pin)牌發展,國(guo)(guo)產(chan)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)業(ye)(ye)的(de)(de)(de)繁榮將為汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)膠的(de)(de)(de)應用(yong)提(ti)(ti)供有力保障。預測未(wei)來3年,我國(guo)(guo)室溫硫化硅(gui)(gui)橡膠在汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)行業(ye)(ye)將以(yi)年均20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重要的(de)(de)(de)非石(shi)油(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消費(fei)量的(de)(de)(de)98%。但因(yin)為(wei)石(shi)油(you)價(jia)格的(de)(de)(de)大幅上漲(zhang),同時我國(guo)在硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關(guan)鍵原(yuan)料有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體的(de)(de)(de)生產(chan)(chan)技(ji)術(shu)方面取(qu)得突破,有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體的(de)(de)(de)生產(chan)(chan)技(ji)術(shu)在2005年前(qian)被幾家跨國(guo)公司壟斷,但目(mu)前(qian)我國(guo)已發展成(cheng)(cheng)為(wei)全球(qiu)有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)單體第1大國(guo),這2個方面原(yuan)因(yin)使硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價(jia)格從(cong)2011年起開始(shi)低于石(shi)油(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大宗石(shi)油(you)基橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉價(jia)的(de)(de)(de)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始(shi)大規模替(ti)代石(shi)油(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大拓展有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)(chan)業(ye)的(de)(de)(de)市場空間,同時將帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)樹脂等其他有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)(chan)品(pin)的(de)(de)(de)消費(fei)。