硅橡膠是指主(zhu)鏈由(you)硅(gui)和(he)氧(yang)原子(zi)交替構成,硅(gui)原子(zi)上通(tong)常連有(you)兩個有(you)機基(ji)(ji)團(tuan)的(de)橡膠(jiao)。普通(tong)的(de)硅(gui)橡膠(jiao)主(zhu)要由(you)含甲基(ji)(ji)和(he)少(shao)量(liang)乙烯基(ji)(ji)的(de)硅(gui)氧(yang)鏈節組成。苯基(ji)(ji)的(de)引(yin)入(ru)可(ke)(ke)提(ti)高(gao)(gao)硅(gui)橡膠(jiao)的(de)耐(nai)高(gao)(gao)、低溫(wen)(wen)性(xing)(xing)能(neng)(neng),三氟(fu)丙基(ji)(ji)及氰基(ji)(ji)的(de)引(yin)入(ru)則可(ke)(ke)提(ti)高(gao)(gao)硅(gui)橡膠(jiao)的(de)耐(nai)溫(wen)(wen)及耐(nai)油性(xing)(xing)能(neng)(neng)。硅(gui)橡膠(jiao)耐(nai)低溫(wen)(wen)性(xing)(xing)能(neng)(neng)良好(hao),一般(ban)在-55℃下(xia)仍能(neng)(neng)工作。引(yin)入(ru)苯基(ji)(ji)后,可(ke)(ke)達-73℃。硅(gui)橡膠(jiao)的(de)耐(nai)熱性(xing)(xing)能(neng)(neng)也很突出(chu),在180℃下(xia)可(ke)(ke)長期工作,稍高(gao)(gao)于200℃也能(neng)(neng)承受數周或更長時(shi)間仍有(you)彈(dan)性(xing)(xing),瞬(shun)時(shi)可(ke)(ke)耐(nai)300℃以上的(de)高(gao)(gao)溫(wen)(wen)。硅(gui)橡膠(jiao)的(de)透氣性(xing)(xing)好(hao),氧(yang)氣透過率在合成聚合物中是較高(gao)(gao)的(de)。此(ci)外(wai),硅(gui)橡膠(jiao)還具有(you)生理惰性(xing)(xing)、不會導(dao)致凝血的(de)突出(chu)特性(xing)(xing),因此(ci)在醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠(jiao)分類(lei)的(de)方(fang)法很多,通(tong)常按固化前的(de)形態分為固體硅(gui)(gui)(gui)橡(xiang)膠(jiao)和液(ye)體硅(gui)(gui)(gui)橡(xiang)膠(jiao);按硫(liu)化溫度(du)分為室(shi)溫硫(liu)化硅(gui)(gui)(gui)橡(xiang)膠(jiao),高溫硫(liu)化硅(gui)(gui)(gui)橡(xiang)膠(jiao);按所用單(dan)體的(de)不同(tong)(tong),可分為甲基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao),甲基(ji)(ji)苯(ben)基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠(jiao)等;按性能和用途的(de)不同(tong)(tong)又(you)可分為通(tong)用型(xing)、超耐(nai)低溫型(xing)、超耐(nai)高溫型(xing)、高強力(li)型(xing)、耐(nai)油(you)型(xing)、醫用型(xing)等等。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由(you)美國(guo)(guo)以三氯(lv)化(hua)(hua)鐵(tie)為催化(hua)(hua)劑合成(cheng)的(de)。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)品(pin)問(wen)世。1948年,采用高(gao)比表面積的(de)氣(qi)相(xiang)法(fa)白炭黑補強的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成(cheng)功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍升到實用階段,奠(dian)定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術的(de)基礎(chu)。從二甲基二氯(lv)硅(gui)(gui)烷合成(cheng)開始生產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)(guo)家(jia)有美國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)(zhong)國(guo)(guo)等(deng)。中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)工業化(hua)(hua)研究始于(yu)1957年,多家(jia)研究所和企業陸(lu)續開發出各種硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年底,中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)能(neng)力為135千噸(dun),其中(zhong)(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)(liu)化硅(gui)(gui)橡膠(jiao)是(shi)(shi)指聚(ju)硅(gui)(gui)氧(yang)(yang)烷變成(cheng)(cheng)彈性(xing)體(ti)的過程是(shi)(shi)經過高溫(110-170℃)硫(liu)(liu)化成(cheng)(cheng)型的。它主要以高分(fen)子量的聚(ju)甲基(ji)乙(yi)烯(xi)基(ji)硅(gui)(gui)氧(yang)(yang)烷為生(sheng)膠(jiao),混入補強填料(liao)、硫(liu)(liu)化劑等,在(zai)加(jia)熱加(jia)壓下硫(liu)(liu)化成(cheng)(cheng)彈性(xing)體(ti)。硅(gui)(gui)橡膠(jiao)的補強主要是(shi)(shi)各(ge)(ge)種(zhong)(zhong)類型的白炭黑,可使硫(liu)(liu)化膠(jiao)的強度增加(jia)數十(shi)倍。有時為了降(jiang)低(di)成(cheng)(cheng)本或改善膠(jiao)料(liao)性(xing)能(neng)(neng)及賦予硫(liu)(liu)化膠(jiao)各(ge)(ge)種(zhong)(zhong)特(te)殊的性(xing)能(neng)(neng),也加(jia)入相應的各(ge)(ge)種(zhong)(zhong)添加(jia)劑。硫(liu)(liu)化劑是(shi)(shi)各(ge)(ge)種(zhong)(zhong)有機過氧(yang)(yang)化物或加(jia)成(cheng)(cheng)反應催化劑。
加工成型(xing)方法如圖所示(shi)。一次硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)(xing)高(gao)分子鏈的(de)(de)(de)交聯反應;二次硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)(xing)補(bu)充交聯、驅除硫(liu)化(hua)劑分解(jie)產(chan)物和其他揮發性(xing)化(hua)合物以穩(wen)定硫(liu)化(hua)膠(jiao)的(de)(de)(de)各項(xiang)性(xing)能。常(chang)用的(de)(de)(de)設(she)備有開放式煉(lian)(lian)膠(jiao)機、捏合機及真(zhen)空密煉(lian)(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)膠(jiao)顯著的(de)(de)特(te)征(zheng)是高(gao)溫(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)的(de)(de)強(qiang)度(du)(du)(du)僅(jin)是天然(ran)橡(xiang)膠(jiao)或某些合成橡(xiang)膠(jiao)的(de)(de)一(yi)半,但(dan)在200℃以上的(de)(de)高(gao)溫(wen)(wen)環境下(xia)(xia),硅橡(xiang)膠(jiao)仍能(neng)(neng)(neng)保持一(yi)定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du)(du)(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅橡(xiang)膠(jiao)的(de)(de)玻(bo)璃化溫(wen)(wen)度(du)(du)(du)一(yi)般為-70~-50℃,特(te)殊配(pei)方可達-100℃,表明其(qi)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)。這對(dui)航空、宇航工業的(de)(de)意義(yi)重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)中(zhong)Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及紫外線等(deng)十分穩(wen)定,在不加任何(he)添加劑的(de)(de)情況下(xia)(xia),就(jiu)具(ju)(ju)(ju)有(you)優(you)良的(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)膠(jiao)具(ju)(ju)(ju)有(you)優(you)異(yi)的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)膠(jiao)常溫(wen)(wen)下(xia)(xia)的(de)(de)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通(tong)用(yong)(yong)橡(xiang)膠(jiao)差,但(dan)在150℃的(de)(de)高(gao)溫(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)下(xia)(xia),其(qi)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用(yong)(yong)橡(xiang)膠(jiao)。(6)耐(nai)(nai)油(you)及化學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅橡(xiang)膠(jiao)具(ju)(ju)(ju)有(you)中(zhong)等(deng)的(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)對(dui)空氣(qi)、氮、氧(yang)、二氧(yang)化碳等(deng)氣(qi)體的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)橡(xiang)膠(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅(xiu),與人體組織不粘連,具(ju)(ju)(ju)有(you)抗凝血(xue)作(zuo)用(yong)(yong),對(dui)肌(ji)體組織的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特(te)別適合作(zuo)為醫(yi)用(yong)(yong)材料。
硅橡膠的用量
據中(zhong)國(guo)(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)產(chan)銷分別達(da)到1927.18萬輛和1930.64萬輛,同比分別增長4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)硅(gui)橡膠(jiao)的用(yong)(yong)(yong)量(liang)約達(da)2.0萬t。根據觀研天下的新研究,增加(jia)有(you)機硅(gui)材料在汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部件方面(mian)的用(yong)(yong)(yong)量(liang),可以大(da)幅度提(ti)高(gao)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)的安全性能,因此,汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)產(chan)量(liang)和單車(che)(che)(che)(che)用(yong)(yong)(yong)量(liang)水平的提(ti)高(gao)都將(jiang)推(tui)動汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)工(gong)業(ye)(ye)對硅(gui)橡膠(jiao)需(xu)求(qiu)(qiu)的增加(jia)。國(guo)(guo)(guo)家鼓勵自(zi)主品(pin)牌的汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)發(fa)(fa)展,關鍵汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部件實現自(zi)主化,《2012年(nian)(nian)度黨政機關公務用(yong)(yong)(yong)車(che)(che)(che)(che)選用(yong)(yong)(yong)車(che)(che)(che)(che)型目(mu)錄(征(zheng)求(qiu)(qiu)意見稿)》為(wei)(wei)(wei)自(zi)主品(pin)牌擴(kuo)大(da)在政府(fu)(fu)采購的市場份額,為(wei)(wei)(wei)改變目(mu)前(qian)國(guo)(guo)(guo)內政府(fu)(fu)采購以合資品(pin)牌產(chan)品(pin)為(wei)(wei)(wei)主的局面(mian)提(ti)供(gong)了保障。促(cu)進自(zi)主品(pin)牌發(fa)(fa)展,國(guo)(guo)(guo)產(chan)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)業(ye)(ye)的繁榮將(jiang)為(wei)(wei)(wei)汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)膠(jiao)的應用(yong)(yong)(yong)提(ti)供(gong)有(you)力(li)保障。預(yu)測未來3年(nian)(nian),我國(guo)(guo)(guo)室溫硫化硅(gui)橡膠(jiao)在汽(qi)(qi)(qi)(qi)車(che)(che)(che)(che)行業(ye)(ye)將(jiang)以年(nian)(nian)均20%增長。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重(zhong)要的(de)(de)(de)非石(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消(xiao)費量的(de)(de)(de)98%。但因為石(shi)(shi)油價(jia)格(ge)的(de)(de)(de)大(da)(da)幅上漲,同時我(wo)國在硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關鍵原料有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體(ti)的(de)(de)(de)生產技(ji)術方面(mian)取得突(tu)破,有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體(ti)的(de)(de)(de)生產技(ji)術在2005年前(qian)被幾(ji)家跨國公司壟斷,但目(mu)前(qian)我(wo)國已發展成(cheng)(cheng)為全球有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體(ti)第1大(da)(da)國,這(zhe)2個方面(mian)原因使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價(jia)格(ge)從2011年起開始低(di)于石(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為大(da)(da)宗石(shi)(shi)油基(ji)(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)(cheng)為廉價(jia)的(de)(de)(de)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并(bing)開始大(da)(da)規模替代石(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將(jiang)極大(da)(da)拓展有(you)(you)機(ji)硅(gui)(gui)(gui)產業的(de)(de)(de)市場空間,同時將(jiang)帶動(dong)硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶聯(lian)劑和(he)硅(gui)(gui)(gui)樹脂等其他有(you)(you)機(ji)硅(gui)(gui)(gui)產品的(de)(de)(de)消(xiao)費。