
硅橡膠是(shi)指主鏈由硅(gui)(gui)(gui)和氧原子交替構(gou)成,硅(gui)(gui)(gui)原子上通常連有(you)(you)兩個有(you)(you)機基(ji)(ji)團的(de)(de)(de)(de)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。普通的(de)(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)主要由含甲(jia)基(ji)(ji)和少量乙烯基(ji)(ji)的(de)(de)(de)(de)硅(gui)(gui)(gui)氧鏈節(jie)組(zu)成。苯基(ji)(ji)的(de)(de)(de)(de)引入(ru)可提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)耐(nai)(nai)高(gao)、低(di)溫性(xing)能(neng)(neng)(neng),三氟丙(bing)基(ji)(ji)及(ji)氰基(ji)(ji)的(de)(de)(de)(de)引入(ru)則可提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)耐(nai)(nai)溫及(ji)耐(nai)(nai)油性(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)耐(nai)(nai)低(di)溫性(xing)能(neng)(neng)(neng)良好,一般在(zai)-55℃下(xia)仍能(neng)(neng)(neng)工作。引入(ru)苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)耐(nai)(nai)熱(re)性(xing)能(neng)(neng)(neng)也很突出,在(zai)180℃下(xia)可長期(qi)工作,稍(shao)高(gao)于200℃也能(neng)(neng)(neng)承受數周或更長時(shi)間仍有(you)(you)彈性(xing),瞬時(shi)可耐(nai)(nai)300℃以上的(de)(de)(de)(de)高(gao)溫。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)透(tou)氣性(xing)好,氧氣透(tou)過率在(zai)合成聚合物中是(shi)較高(gao)的(de)(de)(de)(de)。此(ci)外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)還(huan)具有(you)(you)生理惰(duo)性(xing)、不會導致凝(ning)血的(de)(de)(de)(de)突出特(te)性(xing),因(yin)此(ci)在(zai)醫用(yong)領域應用(yong)廣泛(fan)。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠分(fen)(fen)類的(de)方法很(hen)多,通常按固化(hua)前的(de)形態分(fen)(fen)為固體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠和液體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠;按硫化(hua)溫(wen)度(du)分(fen)(fen)為室溫(wen)硫化(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠,高溫(wen)硫化(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠;按所用單體的(de)不同,可(ke)分(fen)(fen)為甲基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠,甲基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠等;按性(xing)能(neng)和用途的(de)不同又可(ke)分(fen)(fen)為通用型(xing)、超耐(nai)低溫(wen)型(xing)、超耐(nai)高溫(wen)型(xing)、高強(qiang)力型(xing)、耐(nai)油型(xing)、醫(yi)用型(xing)等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)早(zao)期是由(you)美(mei)國(guo)(guo)以(yi)三氯化鐵為(wei)催化劑合(he)(he)成(cheng)的(de)。1945年(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)產品問世。1948年(nian),采(cai)用(yong)高(gao)比表(biao)面積的(de)氣相法白炭黑(hei)補強的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)研制成(cheng)功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)性能躍升到(dao)實用(yong)階段,奠(dian)定了(le)現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)(sheng)產技術的(de)基(ji)礎。從二甲基(ji)二氯硅(gui)(gui)烷(wan)合(he)(he)成(cheng)開(kai)(kai)始生(sheng)(sheng)產硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)國(guo)(guo)家(jia)(jia)有(you)美(mei)國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和(he)中(zhong)(zhong)國(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)工業化研究(jiu)始于1957年(nian),多家(jia)(jia)研究(jiu)所和(he)企(qi)業陸續開(kai)(kai)發出各種(zhong)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)底(di),中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)(sheng)產能力(li)為(wei)135千(qian)噸,其(qi)中(zhong)(zhong)高(gao)溫(wen)膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)硅橡膠是(shi)指聚硅氧(yang)烷(wan)變成(cheng)(cheng)彈性體的(de)(de)(de)(de)過程是(shi)經過高溫(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)型(xing)的(de)(de)(de)(de)。它主要(yao)以高分子(zi)量的(de)(de)(de)(de)聚甲基乙(yi)烯基硅氧(yang)烷(wan)為(wei)生(sheng)膠,混入補(bu)強(qiang)填料、硫(liu)(liu)化(hua)(hua)劑等,在加(jia)熱加(jia)壓(ya)下硫(liu)(liu)化(hua)(hua)成(cheng)(cheng)彈性體。硅橡膠的(de)(de)(de)(de)補(bu)強(qiang)主要(yao)是(shi)各(ge)種(zhong)類型(xing)的(de)(de)(de)(de)白(bai)炭黑(hei),可使硫(liu)(liu)化(hua)(hua)膠的(de)(de)(de)(de)強(qiang)度增加(jia)數(shu)十倍。有(you)時為(wei)了(le)降低成(cheng)(cheng)本或改善膠料性能及賦予硫(liu)(liu)化(hua)(hua)膠各(ge)種(zhong)特殊的(de)(de)(de)(de)性能,也加(jia)入相(xiang)應的(de)(de)(de)(de)各(ge)種(zhong)添加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是(shi)各(ge)種(zhong)有(you)機過氧(yang)化(hua)(hua)物(wu)或加(jia)成(cheng)(cheng)反(fan)應催化(hua)(hua)劑。
加工成(cheng)型方法如圖所示(shi)。一(yi)次(ci)硫(liu)化的目的是(shi)進(jin)行(xing)(xing)高分(fen)子(zi)鏈(lian)的交聯反應;二次(ci)硫(liu)化的目的是(shi)進(jin)行(xing)(xing)補充交聯、驅除硫(liu)化劑分(fen)解產物和其他揮發性化合(he)物以穩定硫(liu)化膠(jiao)的各(ge)項(xiang)性能。常(chang)用的設備有開放式煉膠(jiao)機、捏合(he)機及真空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯(xian)(xian)著的特(te)征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的強(qiang)度僅是(shi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或某(mou)些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的一半,但在200℃以上(shang)的高(gao)溫(wen)(wen)(wen)環(huan)境(jing)下(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一定(ding)的柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(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)無明顯(xian)(xian)變化(hua)。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的玻(bo)璃(li)化(hua)溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方可達-100℃,表明其(qi)(qi)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對航空、宇航工業(ye)的意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)、臭氧(yang)及紫(zi)外線(xian)等(deng)(deng)十(shi)分穩定(ding),在不(bu)(bu)加(jia)任(ren)何添加(jia)劑的情(qing)況下(xia)(xia),就具(ju)有(you)優(you)良的耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)優(you)異的絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)(xia)的物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)(bi)通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的高(gao)溫(wen)(wen)(wen)和(he)-50℃的低(di)溫(wen)(wen)(wen)下(xia)(xia),其(qi)(qi)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)中(zhong)等(deng)(deng)的耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對空氣、氮(dan)、氧(yang)、二(er)氧(yang)化(hua)碳(tan)等(deng)(deng)氣體的透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)(bi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無毒,無味,無嗅(xiu),與人(ren)體組織不(bu)(bu)粘連(lian),具(ju)有(you)抗凝血作(zuo)用,對肌體組織的反(fan)應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特(te)別適合作(zuo)為醫用材料。
硅橡膠的用量
據(ju)中國汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)協會統(tong)計(ji),2012年(nian),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)銷(xiao)分(fen)別(bie)達(da)到(dao)1927.18萬輛和(he)(he)1930.64萬輛,同比分(fen)別(bie)增(zeng)長4.63%和(he)(he)4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)硅(gui)(gui)橡(xiang)膠(jiao)的(de)用(yong)量(liang)約達(da)2.0萬t。根據(ju)觀研(yan)天下的(de)新研(yan)究,增(zeng)加有(you)機(ji)硅(gui)(gui)材料在(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零(ling)部件方面的(de)用(yong)量(liang),可以(yi)(yi)大(da)幅度提(ti)高汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)的(de)安全性能,因此(ci),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)量(liang)和(he)(he)單車(che)(che)(che)用(yong)量(liang)水平(ping)的(de)提(ti)高都將(jiang)推動汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)對硅(gui)(gui)橡(xiang)膠(jiao)需求的(de)增(zeng)加。國家鼓勵(li)自主(zhu)品(pin)牌(pai)的(de)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)發展,關鍵汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零(ling)部件實(shi)現自主(zhu)化,《2012年(nian)度黨政(zheng)機(ji)關公(gong)務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目錄(征求意(yi)見稿)》為自主(zhu)品(pin)牌(pai)擴大(da)在(zai)政(zheng)府采購的(de)市場份額,為改變目前國內政(zheng)府采購以(yi)(yi)合資品(pin)牌(pai)產(chan)品(pin)為主(zhu)的(de)局面提(ti)供了保(bao)障。促進(jin)自主(zhu)品(pin)牌(pai)發展,國產(chan)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)業(ye)(ye)(ye)的(de)繁榮將(jiang)為汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的(de)應用(yong)提(ti)供有(you)力(li)保(bao)障。預測(ce)未(wei)來3年(nian),我(wo)國室(shi)溫硫化硅(gui)(gui)橡(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)行業(ye)(ye)(ye)將(jiang)以(yi)(yi)年(nian)均20%增(zeng)長。
此(ci)外,硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)是重要的(de)非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)橡膠(jiao)(jiao)(jiao)(jiao),約(yue)占非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)橡膠(jiao)(jiao)(jiao)(jiao)消(xiao)(xiao)費量的(de)98%。但(dan)因(yin)為(wei)石(shi)(shi)油(you)價(jia)格(ge)的(de)大(da)幅上漲,同時我國在(zai)硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)關鍵原料有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體(ti)的(de)生(sheng)產技術方(fang)面(mian)(mian)取得突破,有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體(ti)的(de)生(sheng)產技術在(zai)2005年前(qian)被幾(ji)家跨(kua)國公(gong)司壟斷,但(dan)目前(qian)我國已發展(zhan)成(cheng)為(wei)全球有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體(ti)第1大(da)國,這(zhe)2個(ge)方(fang)面(mian)(mian)原因(yin)使硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)價(jia)格(ge)從2011年起開始(shi)低于(yu)石(shi)(shi)油(you)基(ji)合成(cheng)橡膠(jiao)(jiao)(jiao)(jiao),僅約(yue)為(wei)大(da)宗石(shi)(shi)油(you)基(ji)橡膠(jiao)(jiao)(jiao)(jiao)的(de)80%~90%,成(cheng)為(wei)廉(lian)價(jia)的(de)合成(cheng)橡膠(jiao)(jiao)(jiao)(jiao),并開始(shi)大(da)規模替代石(shi)(shi)油(you)基(ji)合成(cheng)橡膠(jiao)(jiao)(jiao)(jiao)。這(zhe)將(jiang)(jiang)極(ji)大(da)拓展(zhan)有(you)機(ji)(ji)硅(gui)(gui)(gui)產業(ye)的(de)市場空間,同時將(jiang)(jiang)帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹脂等其他有(you)機(ji)(ji)硅(gui)(gui)(gui)產品的(de)消(xiao)(xiao)費。