硅橡膠是指(zhi)主鏈由硅(gui)和氧原子交替構(gou)成(cheng)(cheng),硅(gui)原子上通(tong)(tong)常連(lian)有兩個有機基(ji)團的(de)橡(xiang)(xiang)膠(jiao)。普(pu)通(tong)(tong)的(de)硅(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)和少量乙烯(xi)基(ji)的(de)硅(gui)氧鏈節組成(cheng)(cheng)。苯基(ji)的(de)引(yin)入可(ke)提高(gao)(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)高(gao)(gao)(gao)、低溫性(xing)(xing)(xing)能,三氟丙基(ji)及氰(qing)基(ji)的(de)引(yin)入則(ze)可(ke)提高(gao)(gao)(gao)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)溫及耐(nai)油性(xing)(xing)(xing)能。硅(gui)橡(xiang)(xiang)膠(jiao)耐(nai)低溫性(xing)(xing)(xing)能良好(hao),一(yi)般在-55℃下仍能工(gong)(gong)作(zuo)(zuo)。引(yin)入苯基(ji)后,可(ke)達-73℃。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)耐(nai)熱性(xing)(xing)(xing)能也(ye)很突(tu)出,在180℃下可(ke)長(chang)期工(gong)(gong)作(zuo)(zuo),稍高(gao)(gao)(gao)于200℃也(ye)能承(cheng)受數周(zhou)或(huo)更長(chang)時間(jian)仍有彈(dan)性(xing)(xing)(xing),瞬(shun)時可(ke)耐(nai)300℃以上的(de)高(gao)(gao)(gao)溫。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)透(tou)氣(qi)性(xing)(xing)(xing)好(hao),氧氣(qi)透(tou)過率在合(he)(he)成(cheng)(cheng)聚合(he)(he)物中是較高(gao)(gao)(gao)的(de)。此外,硅(gui)橡(xiang)(xiang)膠(jiao)還具(ju)有生(sheng)理惰性(xing)(xing)(xing)、不會導致凝(ning)血的(de)突(tu)出特性(xing)(xing)(xing),因此在醫(yi)用領域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)分類的方(fang)法很(hen)多(duo),通(tong)常(chang)按(an)(an)固(gu)化前(qian)的形態分為(wei)(wei)固(gu)體(ti)(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)和液體(ti)(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)硫(liu)化溫(wen)(wen)度分為(wei)(wei)室溫(wen)(wen)硫(liu)化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),高(gao)溫(wen)(wen)硫(liu)化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)所(suo)用(yong)(yong)單體(ti)(ti)的不(bu)同,可分為(wei)(wei)甲(jia)基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲(jia)基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟(fu)硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)等(deng);按(an)(an)性能和用(yong)(yong)途(tu)的不(bu)同又可分為(wei)(wei)通(tong)用(yong)(yong)型(xing)、超耐低溫(wen)(wen)型(xing)、超耐高(gao)溫(wen)(wen)型(xing)、高(gao)強(qiang)力型(xing)、耐油型(xing)、醫用(yong)(yong)型(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)膠(jiao)(jiao)早期(qi)是由美國(guo)以三氯化鐵為催(cui)化劑合成的(de)。1945年(nian)(nian),硅(gui)橡(xiang)膠(jiao)(jiao)產品問世(shi)。1948年(nian)(nian),采(cai)用高(gao)比表面(mian)積(ji)的(de)氣相(xiang)法(fa)白炭(tan)黑補(bu)強的(de)硅(gui)橡(xiang)膠(jiao)(jiao)研(yan)制成功,使硅(gui)橡(xiang)膠(jiao)(jiao)的(de)性能(neng)躍升到實(shi)用階段,奠(dian)定了現代硅(gui)橡(xiang)膠(jiao)(jiao)生(sheng)產技術的(de)基礎(chu)。從二甲基二氯硅(gui)烷(wan)合成開(kai)始生(sheng)產硅(gui)橡(xiang)膠(jiao)(jiao)的(de)國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)工(gong)業化研(yan)究(jiu)始于(yu)1957年(nian)(nian),多家研(yan)究(jiu)所和企業陸續開(kai)發出各種硅(gui)橡(xiang)膠(jiao)(jiao)。到2003年(nian)(nian)底(di),中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)生(sheng)產能(neng)力為135千(qian)噸,其中(zhong)高(gao)溫膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)(gao)溫硫(liu)(liu)化(hua)(hua)(hua)硅橡(xiang)(xiang)膠(jiao)是(shi)指聚硅氧(yang)烷變成彈性(xing)體的(de)(de)(de)過程是(shi)經(jing)過高(gao)(gao)溫(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)成型(xing)(xing)的(de)(de)(de)。它主要以高(gao)(gao)分子量(liang)的(de)(de)(de)聚甲(jia)基乙(yi)烯(xi)基硅氧(yang)烷為(wei)生膠(jiao),混入補強(qiang)(qiang)填(tian)料、硫(liu)(liu)化(hua)(hua)(hua)劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓下(xia)硫(liu)(liu)化(hua)(hua)(hua)成彈性(xing)體。硅橡(xiang)(xiang)膠(jiao)的(de)(de)(de)補強(qiang)(qiang)主要是(shi)各種(zhong)類型(xing)(xing)的(de)(de)(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)的(de)(de)(de)強(qiang)(qiang)度增加(jia)(jia)數十(shi)倍。有時為(wei)了降低(di)成本或改善膠(jiao)料性(xing)能及賦予硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)各種(zhong)特(te)殊(shu)的(de)(de)(de)性(xing)能,也(ye)加(jia)(jia)入相應(ying)的(de)(de)(de)各種(zhong)添加(jia)(jia)劑(ji)。硫(liu)(liu)化(hua)(hua)(hua)劑(ji)是(shi)各種(zhong)有機(ji)過氧(yang)化(hua)(hua)(hua)物或加(jia)(jia)成反應(ying)催(cui)化(hua)(hua)(hua)劑(ji)。
加工成型方法如圖所示。一次硫(liu)化(hua)的(de)(de)目的(de)(de)是進行高(gao)分子鏈的(de)(de)交聯(lian)反應;二次硫(liu)化(hua)的(de)(de)目的(de)(de)是進行補充交聯(lian)、驅除硫(liu)化(hua)劑分解產物和(he)其他(ta)揮(hui)發性(xing)化(hua)合物以穩定硫(liu)化(hua)膠(jiao)的(de)(de)各項(xiang)性(xing)能。常用的(de)(de)設備(bei)有開放(fang)式(shi)煉(lian)(lian)膠(jiao)機、捏(nie)合機及真空密(mi)煉(lian)(lian)機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特(te)征是高溫(wen)(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅(jin)是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)高溫(wen)(wen)(wen)(wen)(wen)環境下(xia),硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持(chi)一(yi)定的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面(mian)硬(ying)度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻(bo)璃化溫(wen)(wen)(wen)(wen)(wen)度(du)一(yi)般(ban)為(wei)-70~-50℃,特(te)殊(shu)配方可達-100℃,表明其低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)。這對航空、宇航工(gong)業的(de)(de)(de)意義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)、臭氧(yang)及紫外(wai)線等十分穩(wen)定,在不(bu)加(jia)任(ren)何添加(jia)劑的(de)(de)(de)情況下(xia),就具有優(you)良的(de)(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有優(you)異(yi)的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下(xia)的(de)(de)(de)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差(cha),但在150℃的(de)(de)(de)高溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)(wen)下(xia),其物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于(yu)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有中(zhong)等的(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對空氣、氮(dan)、氧(yang)、二氧(yang)化碳等氣體的(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅(xiu),與人體組織不(bu)粘(zhan)連(lian),具有抗凝血作(zuo)用(yong),對肌體組織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)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)(qi)(qi)車(che)(che)工(gong)業協會統計,2012年,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產銷(xiao)分別達(da)(da)到1927.18萬輛(liang)和(he)1930.64萬輛(liang),同(tong)比(bi)分別增(zeng)(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業硅(gui)(gui)橡(xiang)膠的(de)(de)(de)用(yong)(yong)量約(yue)達(da)(da)2.0萬t。根據觀研(yan)天下的(de)(de)(de)新研(yan)究,增(zeng)(zeng)加(jia)有(you)機硅(gui)(gui)材料在(zai)(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部件(jian)(jian)方面的(de)(de)(de)用(yong)(yong)量,可以(yi)大(da)幅度(du)提高(gao)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)(de)安全性能,因(yin)此(ci),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產量和(he)單(dan)車(che)(che)用(yong)(yong)量水平(ping)的(de)(de)(de)提高(gao)都(dou)將推動汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業對(dui)硅(gui)(gui)橡(xiang)膠需求(qiu)的(de)(de)(de)增(zeng)(zeng)加(jia)。國(guo)家(jia)鼓勵自主(zhu)品(pin)(pin)牌的(de)(de)(de)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)發展(zhan),關鍵汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部件(jian)(jian)實現自主(zhu)化(hua),《2012年度(du)黨(dang)政(zheng)機關公務用(yong)(yong)車(che)(che)選用(yong)(yong)車(che)(che)型目(mu)錄(征求(qiu)意(yi)見稿)》為(wei)(wei)自主(zhu)品(pin)(pin)牌擴大(da)在(zai)(zai)政(zheng)府采(cai)購(gou)的(de)(de)(de)市場份額,為(wei)(wei)改變目(mu)前國(guo)內政(zheng)府采(cai)購(gou)以(yi)合資品(pin)(pin)牌產品(pin)(pin)為(wei)(wei)主(zhu)的(de)(de)(de)局(ju)面提供了保障。促(cu)進自主(zhu)品(pin)(pin)牌發展(zhan),國(guo)產汽(qi)(qi)(qi)(qi)(qi)車(che)(che)業的(de)(de)(de)繁(fan)榮將為(wei)(wei)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)膠的(de)(de)(de)應用(yong)(yong)提供有(you)力保障。預測(ce)未來(lai)3年,我國(guo)室溫硫化(hua)硅(gui)(gui)橡(xiang)膠在(zai)(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)行業將以(yi)年均20%增(zeng)(zeng)長(chang)。
此外(wai),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的非石(shi)油(you)(you)基合成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,約占非石(shi)油(you)(you)基合成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠消費量的98%。但因(yin)為石(shi)油(you)(you)價格的大(da)幅上(shang)漲(zhang),同(tong)時我(wo)國在硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的關鍵原(yuan)料有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單體的生產(chan)技術方(fang)面取得(de)突(tu)破,有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單體的生產(chan)技術在2005年前被(bei)幾(ji)家(jia)跨國公司壟斷,但目前我(wo)國已發展(zhan)(zhan)成(cheng)(cheng)(cheng)為全球有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)單體第1大(da)國,這(zhe)2個方(fang)面原(yuan)因(yin)使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的價格從2011年起開始(shi)低于石(shi)油(you)(you)基合成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,僅約為大(da)宗石(shi)油(you)(you)基橡(xiang)(xiang)膠的80%~90%,成(cheng)(cheng)(cheng)為廉(lian)價的合成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,并開始(shi)大(da)規模替代(dai)石(shi)油(you)(you)基合成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠。這(zhe)將極大(da)拓展(zhan)(zhan)有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)業的市場空(kong)間,同(tong)時將帶動硅(gui)(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)(gui)(gui)樹脂等其他有(you)機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)品的消費。