
硅橡膠是指(zhi)主(zhu)鏈由(you)硅(gui)(gui)(gui)(gui)(gui)和氧原子交替(ti)構成(cheng),硅(gui)(gui)(gui)(gui)(gui)原子上(shang)通常連有(you)兩個有(you)機基(ji)團的橡(xiang)膠。普(pu)通的硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠主(zhu)要由(you)含甲基(ji)和少量乙烯基(ji)的硅(gui)(gui)(gui)(gui)(gui)氧鏈節組成(cheng)。苯(ben)基(ji)的引(yin)(yin)入(ru)可(ke)提高(gao)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的耐高(gao)、低溫(wen)性(xing)能,三氟丙基(ji)及氰基(ji)的引(yin)(yin)入(ru)則可(ke)提高(gao)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的耐溫(wen)及耐油性(xing)能。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠耐低溫(wen)性(xing)能良好(hao),一般在-55℃下仍(reng)能工作(zuo)。引(yin)(yin)入(ru)苯(ben)基(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的耐熱性(xing)能也很突出,在180℃下可(ke)長期(qi)工作(zuo),稍高(gao)于200℃也能承(cheng)受數(shu)周或(huo)更長時間仍(reng)有(you)彈性(xing),瞬時可(ke)耐300℃以上(shang)的高(gao)溫(wen)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的透(tou)氣性(xing)好(hao),氧氣透(tou)過率(lv)在合成(cheng)聚合物中(zhong)是較高(gao)的。此外(wai),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠還具有(you)生理惰性(xing)、不(bu)會導致凝血的突出特性(xing),因此在醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)分類的(de)(de)方法很多,通(tong)常按固化(hua)前的(de)(de)形態分為固體硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)和液(ye)體硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao);按硫(liu)化(hua)溫(wen)(wen)度分為室溫(wen)(wen)硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao),高溫(wen)(wen)硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao);按所用單體的(de)(de)不(bu)同,可分為甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)(jiao)等(deng);按性(xing)能(neng)和用途的(de)(de)不(bu)同又可分為通(tong)用型(xing)(xing)、超耐(nai)(nai)低溫(wen)(wen)型(xing)(xing)、超耐(nai)(nai)高溫(wen)(wen)型(xing)(xing)、高強力(li)型(xing)(xing)、耐(nai)(nai)油型(xing)(xing)、醫(yi)用型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早(zao)期(qi)是由美國以三氯化鐵為催化劑合(he)(he)成(cheng)(cheng)的。1945年,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世(shi)。1948年,采用(yong)高比表(biao)面積的氣(qi)相(xiang)法白炭黑補強的硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使(shi)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的性能躍升到實用(yong)階段,奠(dian)定了現(xian)代(dai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術(shu)的基(ji)礎。從(cong)二甲基(ji)二氯硅(gui)(gui)(gui)烷(wan)合(he)(he)成(cheng)(cheng)開始(shi)(shi)生產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的國家有美國。俄羅斯、德(de)國、日本、韓國和中國等。中國硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的工業化研(yan)究始(shi)(shi)于1957年,多家研(yan)究所和企業陸續開發(fa)出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到2003年底,中國硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)能力為135千噸(dun),其(qi)中高溫(wen)膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)(hua)硅橡膠(jiao)是指聚硅氧(yang)烷(wan)變成(cheng)彈(dan)性(xing)(xing)(xing)體的(de)過程是經過高(gao)溫(110-170℃)硫(liu)化(hua)(hua)成(cheng)型(xing)(xing)的(de)。它主(zhu)要(yao)(yao)以高(gao)分子量的(de)聚甲基乙烯基硅氧(yang)烷(wan)為生膠(jiao),混(hun)入補(bu)強填料(liao)、硫(liu)化(hua)(hua)劑(ji)等,在(zai)加熱(re)加壓下(xia)硫(liu)化(hua)(hua)成(cheng)彈(dan)性(xing)(xing)(xing)體。硅橡膠(jiao)的(de)補(bu)強主(zhu)要(yao)(yao)是各種類(lei)型(xing)(xing)的(de)白炭黑(hei),可(ke)使硫(liu)化(hua)(hua)膠(jiao)的(de)強度(du)增(zeng)加數十(shi)倍。有(you)時為了降低成(cheng)本或改善膠(jiao)料(liao)性(xing)(xing)(xing)能及賦予(yu)硫(liu)化(hua)(hua)膠(jiao)各種特殊的(de)性(xing)(xing)(xing)能,也加入相(xiang)應的(de)各種添加劑(ji)。硫(liu)化(hua)(hua)劑(ji)是各種有(you)機(ji)過氧(yang)化(hua)(hua)物或加成(cheng)反應催化(hua)(hua)劑(ji)。
加工成型方法(fa)如圖所(suo)示。一(yi)次(ci)硫(liu)化(hua)的目(mu)的是進行高分子鏈的交聯(lian)反(fan)應;二次(ci)硫(liu)化(hua)的目(mu)的是進行補充交聯(lian)、驅(qu)除硫(liu)化(hua)劑分解產物和其他(ta)揮發性化(hua)合物以穩(wen)定硫(liu)化(hua)膠的各項性能。常用的設備有(you)開放式煉膠機、捏合機及真空密(mi)煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠顯著的(de)(de)(de)特征是高(gao)溫(wen)(wen)(wen)(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)強(qiang)度僅是天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)一(yi)半(ban),但在200℃以上(shang)的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)環境下(xia)(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠仍能(neng)(neng)保持(chi)一(yi)定(ding)的(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)和表面(mian)硬(ying)度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明(ming)顯變化(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)(wen)(wen)度一(yi)般為(wei)-70~-50℃,特殊配方可達(da)-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對航空(kong)(kong)、宇(yu)航工(gong)業的(de)(de)(de)意(yi)義重大。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠中Si-O-Si鍵對氧、臭氧及(ji)紫外線(xian)等(deng)十(shi)分穩(wen)定(ding),在不加任(ren)何添加劑的(de)(de)(de)情(qing)況下(xia)(xia),就具(ju)有(you)優良的(de)(de)(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠具(ju)有(you)優異的(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠常(chang)(chang)溫(wen)(wen)(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠差(cha),但在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)(wen)下(xia)(xia),其物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠。(6)耐油及(ji)化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠具(ju)有(you)中等(deng)的(de)(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠對空(kong)(kong)氣、氮、氧、二氧化(hua)碳(tan)等(deng)氣體(ti)的(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠無毒,無味,無嗅,與(yu)人體(ti)組織不粘連,具(ju)有(you)抗凝血(xue)作(zuo)用(yong),對肌體(ti)組織的(de)(de)(de)反(fan)應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特別適合作(zuo)為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)協會(hui)統計(ji),2012年,汽(qi)(qi)(qi)車(che)(che)產銷分別達到1927.18萬輛和(he)1930.64萬輛,同(tong)比分別增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)(de)用量(liang)(liang)約達2.0萬t。根據觀研天下的(de)(de)(de)新研究,增(zeng)加有(you)機硅(gui)(gui)(gui)材(cai)料在汽(qi)(qi)(qi)車(che)(che)零部件(jian)方(fang)面的(de)(de)(de)用量(liang)(liang),可以(yi)大(da)幅度(du)(du)提(ti)高汽(qi)(qi)(qi)車(che)(che)的(de)(de)(de)安全(quan)性能,因(yin)此,汽(qi)(qi)(qi)車(che)(che)產量(liang)(liang)和(he)單車(che)(che)用量(liang)(liang)水平的(de)(de)(de)提(ti)高都將推動汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)對硅(gui)(gui)(gui)橡膠(jiao)需求的(de)(de)(de)增(zeng)加。國(guo)家鼓勵自(zi)主品(pin)牌(pai)的(de)(de)(de)汽(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)車(che)(che)零部件(jian)實現自(zi)主化,《2012年度(du)(du)黨政機關公務用車(che)(che)選用車(che)(che)型目(mu)錄(征求意見(jian)稿)》為自(zi)主品(pin)牌(pai)擴大(da)在政府采購的(de)(de)(de)市場(chang)份額,為改變目(mu)前國(guo)內(nei)政府采購以(yi)合資品(pin)牌(pai)產品(pin)為主的(de)(de)(de)局面提(ti)供(gong)了保(bao)障。促(cu)進自(zi)主品(pin)牌(pai)發展,國(guo)產汽(qi)(qi)(qi)車(che)(che)業(ye)(ye)的(de)(de)(de)繁榮將為汽(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)(de)(de)應用提(ti)供(gong)有(you)力保(bao)障。預測(ce)未來(lai)3年,我國(guo)室溫硫化硅(gui)(gui)(gui)橡膠(jiao)在汽(qi)(qi)(qi)車(che)(che)行業(ye)(ye)將以(yi)年均20%增(zeng)長。
此外,硅(gui)橡(xiang)(xiang)膠(jiao)是重(zhong)要的(de)(de)(de)(de)非石(shi)油(you)基(ji)(ji)合(he)成橡(xiang)(xiang)膠(jiao),約占(zhan)非石(shi)油(you)基(ji)(ji)合(he)成橡(xiang)(xiang)膠(jiao)消費(fei)量的(de)(de)(de)(de)98%。但因為(wei)(wei)石(shi)油(you)價(jia)格的(de)(de)(de)(de)大(da)幅上漲,同(tong)時(shi)我國(guo)在(zai)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)關鍵原料有(you)機(ji)(ji)(ji)硅(gui)單體(ti)(ti)的(de)(de)(de)(de)生產技(ji)(ji)術(shu)方(fang)面取得突破,有(you)機(ji)(ji)(ji)硅(gui)單體(ti)(ti)的(de)(de)(de)(de)生產技(ji)(ji)術(shu)在(zai)2005年前(qian)被幾家跨(kua)國(guo)公司壟斷,但目前(qian)我國(guo)已發(fa)展(zhan)成為(wei)(wei)全球(qiu)有(you)機(ji)(ji)(ji)硅(gui)單體(ti)(ti)第(di)1大(da)國(guo),這2個(ge)方(fang)面原因使硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)價(jia)格從2011年起開始低于石(shi)油(you)基(ji)(ji)合(he)成橡(xiang)(xiang)膠(jiao),僅(jin)約為(wei)(wei)大(da)宗石(shi)油(you)基(ji)(ji)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)80%~90%,成為(wei)(wei)廉(lian)價(jia)的(de)(de)(de)(de)合(he)成橡(xiang)(xiang)膠(jiao),并開始大(da)規模(mo)替代石(shi)油(you)基(ji)(ji)合(he)成橡(xiang)(xiang)膠(jiao)。這將(jiang)極大(da)拓展(zhan)有(you)機(ji)(ji)(ji)硅(gui)產業的(de)(de)(de)(de)市場空間,同(tong)時(shi)將(jiang)帶動硅(gui)油(you)、硅(gui)烷(wan)偶聯劑和硅(gui)樹脂等其他有(you)機(ji)(ji)(ji)硅(gui)產品的(de)(de)(de)(de)消費(fei)。