硅橡膠是指主(zhu)鏈由(you)硅(gui)(gui)(gui)(gui)和(he)氧原子交替構成(cheng),硅(gui)(gui)(gui)(gui)原子上通常連有(you)(you)兩個有(you)(you)機基團的(de)(de)(de)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)主(zhu)要由(you)含甲基和(he)少量乙烯基的(de)(de)(de)硅(gui)(gui)(gui)(gui)氧鏈節(jie)組成(cheng)。苯基的(de)(de)(de)引入(ru)可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐高(gao)、低溫性(xing)能,三(san)氟(fu)丙基及(ji)氰(qing)基的(de)(de)(de)引入(ru)則可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐溫及(ji)耐油(you)性(xing)能。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低溫性(xing)能良(liang)好,一般在-55℃下仍能工(gong)作。引入(ru)苯基后,可達-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐熱性(xing)能也(ye)很突(tu)(tu)出,在180℃下可長期工(gong)作,稍高(gao)于200℃也(ye)能承受(shou)數周或更長時間仍有(you)(you)彈性(xing),瞬(shun)時可耐300℃以上的(de)(de)(de)高(gao)溫。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)透(tou)氣(qi)性(xing)好,氧氣(qi)透(tou)過(guo)率在合(he)(he)成(cheng)聚合(he)(he)物中(zhong)是較高(gao)的(de)(de)(de)。此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)還具(ju)有(you)(you)生(sheng)理惰(duo)性(xing)、不會導致凝血的(de)(de)(de)突(tu)(tu)出特(te)性(xing),因此在醫用(yong)領(ling)域應用(yong)廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)分(fen)類的方法很多,通(tong)常按(an)固(gu)化(hua)前的形態分(fen)為(wei)固(gu)體(ti)(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)和(he)液體(ti)(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)硫化(hua)溫(wen)度分(fen)為(wei)室溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao),高溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)所用單體(ti)(ti)的不同,可分(fen)為(wei)甲基乙烯(xi)基硅(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基苯基乙烯(xi)基硅(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)等;按(an)性能和(he)用途的不同又可分(fen)為(wei)通(tong)用型(xing)(xing)、超耐(nai)低溫(wen)型(xing)(xing)、超耐(nai)高溫(wen)型(xing)(xing)、高強力(li)型(xing)(xing)、耐(nai)油(you)型(xing)(xing)、醫用型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)早期是由美(mei)國(guo)(guo)以三氯化鐵為催化劑(ji)合(he)成(cheng)的(de)。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)產(chan)品問世。1948年(nian),采(cai)用高比表(biao)面積(ji)的(de)氣相法白炭黑補強(qiang)的(de)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)研(yan)制成(cheng)功,使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)性能躍升到實用階段,奠(dian)定了現(xian)代硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)技術的(de)基(ji)(ji)礎。從二甲(jia)基(ji)(ji)二氯硅(gui)(gui)(gui)烷合(he)成(cheng)開始(shi)生(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)(guo)家有美(mei)國(guo)(guo)。俄羅斯、德(de)國(guo)(guo)、日(ri)本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)(ye)化研(yan)究(jiu)(jiu)始(shi)于(yu)1957年(nian),多家研(yan)究(jiu)(jiu)所和企業(ye)(ye)陸(lu)續開發(fa)出各種(zhong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)能力為135千(qian)噸(dun),其中(zhong)高溫膠(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)化(hua)(hua)硅橡(xiang)膠(jiao)是(shi)指聚硅氧烷變(bian)成(cheng)彈性(xing)體(ti)的(de)過程是(shi)經過高(gao)溫(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)型的(de)。它主(zhu)要(yao)以高(gao)分子量的(de)聚甲基(ji)(ji)乙烯基(ji)(ji)硅氧烷為生膠(jiao),混入補強(qiang)填(tian)料、硫(liu)(liu)化(hua)(hua)劑(ji)等(deng),在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)彈性(xing)體(ti)。硅橡(xiang)膠(jiao)的(de)補強(qiang)主(zhu)要(yao)是(shi)各種類型的(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)的(de)強(qiang)度(du)增加(jia)數十倍。有時(shi)為了降(jiang)低成(cheng)本或改善膠(jiao)料性(xing)能(neng)及賦予(yu)硫(liu)(liu)化(hua)(hua)膠(jiao)各種特殊的(de)性(xing)能(neng),也(ye)加(jia)入相應(ying)(ying)的(de)各種添加(jia)劑(ji)。硫(liu)(liu)化(hua)(hua)劑(ji)是(shi)各種有機過氧化(hua)(hua)物或加(jia)成(cheng)反(fan)應(ying)(ying)催化(hua)(hua)劑(ji)。
加工成(cheng)型方法如圖所示。一(yi)次硫(liu)化(hua)的(de)目的(de)是進行(xing)(xing)高分(fen)子(zi)鏈的(de)交聯反應;二次硫(liu)化(hua)的(de)目的(de)是進行(xing)(xing)補充交聯、驅除硫(liu)化(hua)劑分(fen)解產(chan)物和(he)其他揮發性化(hua)合物以穩(wen)定硫(liu)化(hua)膠的(de)各項性能。常(chang)用的(de)設備有開放(fang)式煉(lian)膠機、捏(nie)合機及真空(kong)密(mi)煉(lian)機。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)特征是(shi)高溫(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)常溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)強(qiang)度(du)僅是(shi)天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)一(yi)半,但在(zai)200℃以上(shang)的(de)(de)(de)(de)高溫(wen)(wen)環境(jing)下(xia)(xia),硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保(bao)持一(yi)定(ding)(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無明顯變化(hua)(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)(hua)溫(wen)(wen)度(du)一(yi)般(ban)為-70~-50℃,特殊(shu)配方可達(da)-100℃,表明其(qi)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)異。這對(dui)(dui)航(hang)空(kong)、宇航(hang)工業(ye)的(de)(de)(de)(de)意義(yi)重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧、臭氧及紫(zi)外線(xian)等(deng)十分穩定(ding)(ding),在(zai)不加(jia)(jia)任(ren)何添加(jia)(jia)劑的(de)(de)(de)(de)情況下(xia)(xia),就(jiu)具有優(you)(you)良的(de)(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具有優(you)(you)異的(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)(xing)(xing)和耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)下(xia)(xia)的(de)(de)(de)(de)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)(de)高溫(wen)(wen)和-50℃的(de)(de)(de)(de)低溫(wen)(wen)下(xia)(xia),其(qi)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)于通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐油及化(hua)(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具有中等(deng)的(de)(de)(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空(kong)氣(qi)、氮、氧、二氧化(hua)(hua)碳等(deng)氣(qi)體(ti)的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)比天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高出30-50倍。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無毒,無味,無嗅,與人體(ti)組織(zhi)不粘(zhan)連,具有抗凝血作用(yong)(yong),對(dui)(dui)肌體(ti)組織(zhi)的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)非(fei)常少。特別適(shi)合(he)作為醫用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)車(che)(che)工(gong)業協會統計(ji),2012年(nian),汽(qi)(qi)車(che)(che)產(chan)銷分別(bie)達(da)到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同比分別(bie)增(zeng)(zeng)長4.63%和(he)4.33%,汽(qi)(qi)車(che)(che)工(gong)業硅橡膠(jiao)的(de)用(yong)(yong)(yong)量約達(da)2.0萬(wan)t。根據觀研天下的(de)新研究,增(zeng)(zeng)加(jia)有(you)機硅材(cai)料在汽(qi)(qi)車(che)(che)零部件(jian)方面的(de)用(yong)(yong)(yong)量,可(ke)以(yi)大幅(fu)度提(ti)高(gao)汽(qi)(qi)車(che)(che)的(de)安全性能,因此(ci),汽(qi)(qi)車(che)(che)產(chan)量和(he)單車(che)(che)用(yong)(yong)(yong)量水平的(de)提(ti)高(gao)都將(jiang)推動(dong)汽(qi)(qi)車(che)(che)工(gong)業對硅橡膠(jiao)需(xu)求的(de)增(zeng)(zeng)加(jia)。國(guo)(guo)家鼓勵自主品(pin)牌(pai)的(de)汽(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)車(che)(che)零部件(jian)實現(xian)自主化(hua),《2012年(nian)度黨(dang)政(zheng)(zheng)機關公(gong)務用(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)車(che)(che)型目錄(征求意見稿)》為自主品(pin)牌(pai)擴(kuo)大在政(zheng)(zheng)府采購的(de)市場份額,為改變目前國(guo)(guo)內政(zheng)(zheng)府采購以(yi)合資(zi)品(pin)牌(pai)產(chan)品(pin)為主的(de)局(ju)面提(ti)供(gong)了(le)保障。促進自主品(pin)牌(pai)發展,國(guo)(guo)產(chan)汽(qi)(qi)車(che)(che)業的(de)繁榮將(jiang)為汽(qi)(qi)車(che)(che)膠(jiao)的(de)應用(yong)(yong)(yong)提(ti)供(gong)有(you)力保障。預測(ce)未來3年(nian),我國(guo)(guo)室溫硫化(hua)硅橡膠(jiao)在汽(qi)(qi)車(che)(che)行業將(jiang)以(yi)年(nian)均(jun)20%增(zeng)(zeng)長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要的非(fei)石油基合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非(fei)石油基合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消(xiao)費(fei)量(liang)的98%。但因為(wei)(wei)(wei)石油價格的大(da)幅上漲,同時我(wo)國在硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的關鍵原料有(you)機(ji)(ji)硅(gui)(gui)單體的生產(chan)技術方面取(qu)得(de)突破,有(you)機(ji)(ji)硅(gui)(gui)單體的生產(chan)技術在2005年(nian)前(qian)被(bei)幾(ji)家跨國公司壟斷(duan),但目前(qian)我(wo)國已(yi)發展(zhan)成(cheng)(cheng)為(wei)(wei)(wei)全球(qiu)有(you)機(ji)(ji)硅(gui)(gui)單體第1大(da)國,這2個(ge)方面原因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的價格從2011年(nian)起(qi)開(kai)始低于石油基合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅約為(wei)(wei)(wei)大(da)宗石油基橡(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)(cheng)為(wei)(wei)(wei)廉價的合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并(bing)開(kai)始大(da)規模(mo)替代(dai)石油基合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將極大(da)拓展(zhan)有(you)機(ji)(ji)硅(gui)(gui)產(chan)業的市場空間(jian),同時將帶動硅(gui)(gui)油、硅(gui)(gui)烷(wan)偶聯(lian)劑和硅(gui)(gui)樹脂等其他有(you)機(ji)(ji)硅(gui)(gui)產(chan)品的消(xiao)費(fei)。