
硅橡膠是(shi)指(zhi)主(zhu)鏈由硅(gui)(gui)(gui)和氧(yang)原子交替構成(cheng),硅(gui)(gui)(gui)原子上通常連(lian)有(you)兩個有(you)機(ji)基(ji)團(tuan)的(de)(de)(de)(de)(de)橡(xiang)膠(jiao)。普通的(de)(de)(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)主(zhu)要由含(han)甲基(ji)和少量乙(yi)烯基(ji)的(de)(de)(de)(de)(de)硅(gui)(gui)(gui)氧(yang)鏈節(jie)組(zu)成(cheng)。苯基(ji)的(de)(de)(de)(de)(de)引(yin)入可提高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)耐(nai)(nai)高(gao)、低溫性(xing)(xing)能(neng)(neng),三氟丙基(ji)及(ji)氰基(ji)的(de)(de)(de)(de)(de)引(yin)入則(ze)可提高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)耐(nai)(nai)溫及(ji)耐(nai)(nai)油性(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)耐(nai)(nai)低溫性(xing)(xing)能(neng)(neng)良(liang)好,一般(ban)在-55℃下仍(reng)能(neng)(neng)工作。引(yin)入苯基(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)耐(nai)(nai)熱性(xing)(xing)能(neng)(neng)也很突出(chu),在180℃下可長(chang)期工作,稍高(gao)于200℃也能(neng)(neng)承受數周或更長(chang)時(shi)間仍(reng)有(you)彈性(xing)(xing),瞬(shun)時(shi)可耐(nai)(nai)300℃以上的(de)(de)(de)(de)(de)高(gao)溫。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)透氣性(xing)(xing)好,氧(yang)氣透過率在合成(cheng)聚合物中是(shi)較高(gao)的(de)(de)(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)還具(ju)有(you)生理惰性(xing)(xing)、不會導致凝血(xue)的(de)(de)(de)(de)(de)突出(chu)特性(xing)(xing),因此在醫用領(ling)域(yu)應(ying)用廣泛。
主要品種
硅(gui)(gui)(gui)橡膠(jiao)分類的(de)(de)方法很多,通常按(an)(an)(an)固(gu)化前的(de)(de)形態(tai)分為固(gu)體(ti)硅(gui)(gui)(gui)橡膠(jiao)和(he)液(ye)體(ti)硅(gui)(gui)(gui)橡膠(jiao);按(an)(an)(an)硫化溫(wen)(wen)度分為室溫(wen)(wen)硫化硅(gui)(gui)(gui)橡膠(jiao),高溫(wen)(wen)硫化硅(gui)(gui)(gui)橡膠(jiao);按(an)(an)(an)所(suo)用(yong)單體(ti)的(de)(de)不(bu)同,可(ke)分為甲基乙(yi)烯(xi)基硅(gui)(gui)(gui)橡膠(jiao),甲基苯基乙(yi)烯(xi)基硅(gui)(gui)(gui)橡膠(jiao)、氟(fu)硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡膠(jiao)等(deng);按(an)(an)(an)性能和(he)用(yong)途的(de)(de)不(bu)同又可(ke)分為通用(yong)型(xing)(xing)、超(chao)耐低溫(wen)(wen)型(xing)(xing)、超(chao)耐高溫(wen)(wen)型(xing)(xing)、高強力型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)早期(qi)是(shi)由美國(guo)(guo)(guo)以三氯(lv)化(hua)鐵為催化(hua)劑(ji)合成的。1945年(nian),硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)產品問(wen)世。1948年(nian),采用(yong)高比表面積的氣相法白炭黑(hei)補強(qiang)的硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)研(yan)制成功,使硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的性能(neng)躍升到實(shi)用(yong)階(jie)段,奠定了現(xian)代硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產技術(shu)的基礎(chu)。從二甲基二氯(lv)硅(gui)(gui)(gui)(gui)烷合成開始生產硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家(jia)有美國(guo)(guo)(guo)。俄(e)羅斯、德國(guo)(guo)(guo)、日(ri)本、韓(han)國(guo)(guo)(guo)和(he)中(zhong)國(guo)(guo)(guo)等。中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的工業(ye)(ye)化(hua)研(yan)究始于1957年(nian),多家(jia)研(yan)究所和(he)企(qi)業(ye)(ye)陸續開發出各種硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產能(neng)力為135千(qian)噸(dun),其中(zhong)高溫膠(jiao)(jiao)(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)化(hua)硅橡(xiang)膠(jiao)(jiao)是指聚硅氧(yang)(yang)烷(wan)變成(cheng)(cheng)(cheng)彈性(xing)(xing)(xing)體的(de)過(guo)(guo)程是經過(guo)(guo)高溫(110-170℃)硫(liu)化(hua)成(cheng)(cheng)(cheng)型(xing)的(de)。它主(zhu)要(yao)以高分(fen)子量的(de)聚甲基乙烯基硅氧(yang)(yang)烷(wan)為生(sheng)膠(jiao)(jiao),混入補強填料(liao)、硫(liu)化(hua)劑(ji)等,在加(jia)熱(re)加(jia)壓下(xia)硫(liu)化(hua)成(cheng)(cheng)(cheng)彈性(xing)(xing)(xing)體。硅橡(xiang)膠(jiao)(jiao)的(de)補強主(zhu)要(yao)是各種(zhong)類(lei)型(xing)的(de)白炭(tan)黑,可使(shi)硫(liu)化(hua)膠(jiao)(jiao)的(de)強度增加(jia)數十(shi)倍。有時為了降低成(cheng)(cheng)(cheng)本(ben)或(huo)改善(shan)膠(jiao)(jiao)料(liao)性(xing)(xing)(xing)能及賦予硫(liu)化(hua)膠(jiao)(jiao)各種(zhong)特殊的(de)性(xing)(xing)(xing)能,也加(jia)入相應(ying)的(de)各種(zhong)添加(jia)劑(ji)。硫(liu)化(hua)劑(ji)是各種(zhong)有機過(guo)(guo)氧(yang)(yang)化(hua)物或(huo)加(jia)成(cheng)(cheng)(cheng)反應(ying)催化(hua)劑(ji)。
加工成型方法如圖所(suo)示。一次硫(liu)化的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)高分子鏈的(de)(de)(de)交(jiao)(jiao)聯反應;二次硫(liu)化的(de)(de)(de)目的(de)(de)(de)是(shi)進行(xing)補充交(jiao)(jiao)聯、驅除硫(liu)化劑分解(jie)產物和其他揮(hui)發性化合物以穩定硫(liu)化膠的(de)(de)(de)各項(xiang)性能。常用的(de)(de)(de)設備有開放式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)顯著(zhu)的(de)(de)(de)(de)特(te)征是高(gao)(gao)溫(wen)(wen)穩(wen)(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度僅是天然橡(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)一(yi)半,但在(zai)(zai)200℃以上(shang)的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)環境下,硅橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)(neng)保持一(yi)定的(de)(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)明顯變(bian)化(hua)(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)(hua)溫(wen)(wen)度一(yi)般為-70~-50℃,特(te)殊配方可達-100℃,表明其低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)異(yi)。這對(dui)(dui)航空、宇航工業的(de)(de)(de)(de)意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)(dui)氧、臭氧及(ji)(ji)紫外線(xian)等(deng)十分穩(wen)(wen)定,在(zai)(zai)不加(jia)任(ren)何添加(jia)劑(ji)(ji)的(de)(de)(de)(de)情況下,就具(ju)有(you)優(you)良的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)優(you)異(yi)的(de)(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)常溫(wen)(wen)下的(de)(de)(de)(de)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)膠(jiao)(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)和-50℃的(de)(de)(de)(de)低(di)溫(wen)(wen)下,其物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)(ji)化(hua)(hua)學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)的(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)、氮、氧、二氧化(hua)(hua)碳等(deng)氣(qi)(qi)體(ti)的(de)(de)(de)(de)透(tou)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)膠(jiao)(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)組織(zhi)不粘連,具(ju)有(you)抗凝(ning)血作用(yong),對(dui)(dui)肌體(ti)組織(zhi)的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合(he)作為醫(yi)用(yong)材料(liao)。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車工業協會統計,2012年(nian),汽(qi)(qi)車產銷分別達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比分別增長4.63%和4.33%,汽(qi)(qi)車工業硅橡(xiang)膠(jiao)(jiao)的(de)用(yong)量(liang)(liang)約達2.0萬(wan)t。根據觀研(yan)天下(xia)的(de)新研(yan)究,增加有機(ji)硅材料在汽(qi)(qi)車零部件方面(mian)的(de)用(yong)量(liang)(liang),可(ke)以大幅(fu)度(du)提(ti)(ti)高汽(qi)(qi)車的(de)安全性能,因此,汽(qi)(qi)車產量(liang)(liang)和單車用(yong)量(liang)(liang)水平的(de)提(ti)(ti)高都(dou)將(jiang)(jiang)推動(dong)汽(qi)(qi)車工業對硅橡(xiang)膠(jiao)(jiao)需求的(de)增加。國(guo)家(jia)鼓勵(li)自主(zhu)(zhu)品(pin)牌(pai)的(de)汽(qi)(qi)車發展,關(guan)鍵(jian)汽(qi)(qi)車零部件實現(xian)自主(zhu)(zhu)化(hua),《2012年(nian)度(du)黨政機(ji)關(guan)公務用(yong)車選(xuan)用(yong)車型目錄(lu)(征求意見稿)》為自主(zhu)(zhu)品(pin)牌(pai)擴大在政府采購的(de)市場份額(e),為改變目前國(guo)內政府采購以合資品(pin)牌(pai)產品(pin)為主(zhu)(zhu)的(de)局面(mian)提(ti)(ti)供了保障。促進自主(zhu)(zhu)品(pin)牌(pai)發展,國(guo)產汽(qi)(qi)車業的(de)繁榮將(jiang)(jiang)為汽(qi)(qi)車膠(jiao)(jiao)的(de)應用(yong)提(ti)(ti)供有力保障。預測(ce)未(wei)來(lai)3年(nian),我國(guo)室溫硫化(hua)硅橡(xiang)膠(jiao)(jiao)在汽(qi)(qi)車行(xing)業將(jiang)(jiang)以年(nian)均20%增長。
此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)膠是重(zhong)要的(de)非石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠,約(yue)占(zhan)非石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠消(xiao)費量的(de)98%。但因為石(shi)(shi)油(you)(you)價格的(de)大幅上漲,同(tong)時我國(guo)在硅(gui)(gui)(gui)(gui)橡(xiang)膠的(de)關鍵原(yuan)料(liao)有機(ji)硅(gui)(gui)(gui)(gui)單體的(de)生產(chan)技術方(fang)面(mian)取得突破,有機(ji)硅(gui)(gui)(gui)(gui)單體的(de)生產(chan)技術在2005年(nian)前被幾(ji)家跨國(guo)公司壟(long)斷(duan),但目前我國(guo)已發展成(cheng)為全(quan)球有機(ji)硅(gui)(gui)(gui)(gui)單體第1大國(guo),這(zhe)2個方(fang)面(mian)原(yuan)因使硅(gui)(gui)(gui)(gui)橡(xiang)膠的(de)價格從2011年(nian)起開(kai)始低于石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠,僅約(yue)為大宗石(shi)(shi)油(you)(you)基橡(xiang)膠的(de)80%~90%,成(cheng)為廉價的(de)合(he)(he)成(cheng)橡(xiang)膠,并開(kai)始大規模(mo)替代石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)橡(xiang)膠。這(zhe)將極大拓展有機(ji)硅(gui)(gui)(gui)(gui)產(chan)業(ye)的(de)市場空間,同(tong)時將帶動硅(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)(gui)(gui)樹(shu)脂(zhi)等其他有機(ji)硅(gui)(gui)(gui)(gui)產(chan)品的(de)消(xiao)費。