硅橡膠是指主鏈(lian)由硅(gui)(gui)和(he)(he)氧(yang)原(yuan)(yuan)子(zi)交替構成(cheng),硅(gui)(gui)原(yuan)(yuan)子(zi)上通常連有(you)兩個有(you)機基(ji)(ji)團(tuan)的(de)(de)(de)(de)橡(xiang)膠(jiao)(jiao)(jiao)。普(pu)通的(de)(de)(de)(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)主要由含甲基(ji)(ji)和(he)(he)少量乙烯基(ji)(ji)的(de)(de)(de)(de)硅(gui)(gui)氧(yang)鏈(lian)節組成(cheng)。苯基(ji)(ji)的(de)(de)(de)(de)引(yin)入(ru)可(ke)(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐高、低(di)溫性(xing)能(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)(de)引(yin)入(ru)則可(ke)(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐溫及耐油性(xing)能(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)耐低(di)溫性(xing)能(neng)良好,一般在-55℃下(xia)(xia)仍能(neng)工(gong)作(zuo)。引(yin)入(ru)苯基(ji)(ji)后,可(ke)(ke)達(da)-73℃。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐熱性(xing)能(neng)也很突出,在180℃下(xia)(xia)可(ke)(ke)長期工(gong)作(zuo),稍(shao)高于(yu)200℃也能(neng)承(cheng)受數周(zhou)或更(geng)長時(shi)間(jian)仍有(you)彈(dan)性(xing),瞬(shun)時(shi)可(ke)(ke)耐300℃以上的(de)(de)(de)(de)高溫。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)透氣性(xing)好,氧(yang)氣透過率在合(he)成(cheng)聚合(he)物中是較高的(de)(de)(de)(de)。此(ci)外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)還具有(you)生理惰性(xing)、不會(hui)導(dao)致凝血的(de)(de)(de)(de)突出特性(xing),因此(ci)在醫用領域應用廣泛。
主要品種(zhong)
硅(gui)橡膠分(fen)類的方法很多(duo),通(tong)常按固化
前的形態分(fen)為固(gu)體硅橡(xiang)膠和液(ye)體硅橡(xiang)膠;按(an)硫化(hua)溫度分(fen)為室(shi)溫硫化(hua)硅橡(xiang)膠,高(gao)溫硫化(hua)硅橡(xiang)膠;按(an)所用單體的不(bu)同,可分(fen)為甲基(ji)(ji)乙(yi)烯基(ji)(ji)硅橡(xiang)膠,甲基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅橡(xiang)膠、氟硅,腈硅橡(xiang)膠等(deng);按(an)性能(neng)和用途的不(bu)同又(you)可分(fen)為通用型、超(chao)耐(nai)(nai)(nai)低溫型、超(chao)耐(nai)(nai)(nai)高(gao)溫型、高(gao)強力型、耐(nai)(nai)(nai)油型、醫用型等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由(you)美(mei)國(guo)以(yi)三(san)氯化(hua)鐵為(wei)催化(hua)劑合成(cheng)的。1945年(nian)(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品(pin)問世。1948年(nian)(nian),采用高比表面(mian)積的氣相法白炭黑補強的硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的性能躍升到實用階段(duan),奠定了現代(dai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產技術(shu)的基礎。從二(er)甲基二(er)氯硅(gui)烷合成(cheng)開(kai)始生(sheng)產硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)家有美(mei)國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的工(gong)業(ye)化(hua)研(yan)究始于1957年(nian)(nian),多家研(yan)究所和(he)企(qi)業(ye)陸(lu)續開(kai)發出各(ge)種(zhong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底,中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產能力為(wei)135千噸,其中(zhong)高溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫化(hua)硅(gui)橡膠(jiao)是(shi)指聚硅(gui)氧(yang)(yang)烷變成彈性體的過程是(shi)經過高溫(110-170℃)硫化(hua)成型的。它主要(yao)以高分子量的聚甲基(ji)乙烯基(ji)硅(gui)氧(yang)(yang)烷為(wei)生(sheng)膠(jiao),混入補強填(tian)料、硫化(hua)劑(ji)等(deng),在(zai)加熱加壓(ya)下硫化(hua)成彈性體。硅(gui)橡膠(jiao)的補強主要(yao)是(shi)各種(zhong)類型的白炭黑,可使硫化(hua)膠(jiao)的強度增加數十倍(bei)。有時為(wei)了降(jiang)低成本或改善膠(jiao)料性能及賦予硫化(hua)膠(jiao)各種(zhong)特殊的性能,也加入相應的各種(zhong)添加劑(ji)。硫化(hua)劑(ji)是(shi)各種(zhong)有機(ji)過氧(yang)(yang)化(hua)物或加成反應催化(hua)劑(ji)。
加(jia)工成型(xing)方法(fa)如圖所示(shi)。一次硫(liu)化(hua)的目(mu)的是(shi)進行(xing)高分子鏈(lian)的交(jiao)(jiao)聯(lian)反應;二(er)次硫(liu)化(hua)的目(mu)的是(shi)進行(xing)補充(chong)交(jiao)(jiao)聯(lian)、驅除硫(liu)化(hua)劑(ji)分解產(chan)物和其他揮發(fa)性(xing)化(hua)合物以穩定硫(liu)化(hua)膠的各項性(xing)能。常用的設備有開放(fang)式煉(lian)膠機、捏合機及真空密(mi)煉(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)特征是高(gao)溫(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)下硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)僅(jin)是天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一(yi)半,但在(zai)(zai)(zai)200℃以上的(de)(de)高(gao)溫(wen)(wen)環境下,硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保(bao)持一(yi)定(ding)(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無明顯(xian)變(bian)化。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃(li)化溫(wen)(wen)度(du)一(yi)般為-70~-50℃,特殊配方可達-100℃,表明其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)(you)(you)異。這對航(hang)空、宇(yu)航(hang)工業的(de)(de)意義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)紫外線等(deng)(deng)十分(fen)穩定(ding)(ding),在(zai)(zai)(zai)不(bu)加任何添加劑(ji)的(de)(de)情(qing)況(kuang)下,就(jiu)具有優(you)(you)(you)(you)良的(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有優(you)(you)(you)(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)下的(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通(tong)用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在(zai)(zai)(zai)150℃的(de)(de)高(gao)溫(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)下,其(qi)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)(you)(you)于通(tong)用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及(ji)化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有中(zhong)等(deng)(deng)的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)、氮、氧(yang)、二氧(yang)化碳等(deng)(deng)氣(qi)體的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味(wei),無嗅,與人體組(zu)織不(bu)粘連,具有抗凝血作用,對肌體組(zu)織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別適(shi)合作為醫用材料。
硅(gui)橡(xiang)膠的(de)用(yong)量
據(ju)中國(guo)(guo)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業協(xie)會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)銷分別達到1927.18萬(wan)(wan)輛和1930.64萬(wan)(wan)輛,同比分別增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業硅橡(xiang)膠(jiao)(jiao)的(de)(de)用(yong)量(liang)約達2.0萬(wan)(wan)t。根據(ju)觀研(yan)天下(xia)的(de)(de)新研(yan)究(jiu),增(zeng)加有機硅材料在(zai)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)零部件(jian)方面(mian)的(de)(de)用(yong)量(liang),可(ke)以大幅度(du)提(ti)高汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)安全性能,因此,汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)產(chan)量(liang)和單車(che)(che)用(yong)量(liang)水(shui)平的(de)(de)提(ti)高都(dou)將推(tui)動汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業對(dui)硅橡(xiang)膠(jiao)(jiao)需求的(de)(de)增(zeng)加。國(guo)(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)牌的(de)(de)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)零部件(jian)實現自(zi)主(zhu)化,《2012年(nian)(nian)度(du)黨政(zheng)機關公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(征求意見稿)》為(wei)自(zi)主(zhu)品(pin)(pin)牌擴(kuo)大在(zai)政(zheng)府(fu)采購(gou)的(de)(de)市場份額,為(wei)改變目前(qian)國(guo)(guo)內政(zheng)府(fu)采購(gou)以合資品(pin)(pin)牌產(chan)品(pin)(pin)為(wei)主(zhu)的(de)(de)局面(mian)提(ti)供(gong)了(le)保(bao)障(zhang)。促進(jin)自(zi)主(zhu)品(pin)(pin)牌發展,國(guo)(guo)產(chan)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)業的(de)(de)繁榮將為(wei)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)(jiao)的(de)(de)應用(yong)提(ti)供(gong)有力保(bao)障(zhang)。預測未(wei)來3年(nian)(nian),我國(guo)(guo)室溫(wen)硫化硅橡(xiang)膠(jiao)(jiao)在(zai)汽(qi)(qi)(qi)(qi)(qi)(qi)車(che)(che)行業將以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠是(shi)重要的非石(shi)(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠,約占非石(shi)(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠消費(fei)量的98%。但因為(wei)石(shi)(shi)(shi)油(you)(you)價(jia)格的大(da)幅(fu)上漲,同時我(wo)國在硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的關鍵原料(liao)有(you)機(ji)硅(gui)(gui)單(dan)體(ti)(ti)的生(sheng)產(chan)技(ji)術(shu)方面取得突破,有(you)機(ji)硅(gui)(gui)單(dan)體(ti)(ti)的生(sheng)產(chan)技(ji)術(shu)在2005年前被幾家跨國公司壟斷,但目(mu)前我(wo)國已發展(zhan)成(cheng)為(wei)全球有(you)機(ji)硅(gui)(gui)單(dan)體(ti)(ti)第1大(da)國,這2個(ge)方面原因使硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的價(jia)格從2011年起開始低(di)于(yu)石(shi)(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠,僅約為(wei)大(da)宗石(shi)(shi)(shi)油(you)(you)基(ji)(ji)橡(xiang)(xiang)(xiang)(xiang)膠的80%~90%,成(cheng)為(wei)廉價(jia)的合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠,并(bing)開始大(da)規模替代石(shi)(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠。這將極大(da)拓展(zhan)有(you)機(ji)硅(gui)(gui)產(chan)業的市場空(kong)間,同時將帶(dai)動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂等其他(ta)有(you)機(ji)硅(gui)(gui)產(chan)品的消費(fei)。