
硅橡膠是(shi)(shi)指主(zhu)鏈由硅(gui)(gui)(gui)和(he)氧(yang)(yang)原子(zi)交替構成(cheng),硅(gui)(gui)(gui)原子(zi)上(shang)通(tong)常連有(you)(you)兩個有(you)(you)機基(ji)團的(de)(de)(de)橡(xiang)(xiang)膠。普通(tong)的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠主(zhu)要由含甲(jia)基(ji)和(he)少量乙烯基(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧(yang)(yang)鏈節(jie)組成(cheng)。苯(ben)(ben)基(ji)的(de)(de)(de)引入可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)高(gao)(gao)、低溫(wen)(wen)性能,三氟丙基(ji)及(ji)氰基(ji)的(de)(de)(de)引入則(ze)可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)溫(wen)(wen)及(ji)耐(nai)(nai)油性能。硅(gui)(gui)(gui)橡(xiang)(xiang)膠耐(nai)(nai)低溫(wen)(wen)性能良好(hao),一般(ban)在(zai)-55℃下仍能工作。引入苯(ben)(ben)基(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)熱性能也(ye)很突出(chu),在(zai)180℃下可長期(qi)工作,稍高(gao)(gao)于200℃也(ye)能承受數周或更長時間仍有(you)(you)彈性,瞬時可耐(nai)(nai)300℃以上(shang)的(de)(de)(de)高(gao)(gao)溫(wen)(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)透氣(qi)性好(hao),氧(yang)(yang)氣(qi)透過率在(zai)合成(cheng)聚合物(wu)中是(shi)(shi)較高(gao)(gao)的(de)(de)(de)。此(ci)外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠還(huan)具有(you)(you)生理(li)惰性、不會導致凝血的(de)(de)(de)突出(chu)特(te)性,因此(ci)在(zai)醫用領域應用廣(guang)泛(fan)。
主要品種
硅橡(xiang)膠(jiao)(jiao)分(fen)類(lei)的方法很多,通常按固化(hua)(hua)前的形態分(fen)為固體硅橡(xiang)膠(jiao)(jiao)和(he)液(ye)體硅橡(xiang)膠(jiao)(jiao);按硫(liu)化(hua)(hua)溫度分(fen)為室溫硫(liu)化(hua)(hua)硅橡(xiang)膠(jiao)(jiao),高(gao)溫硫(liu)化(hua)(hua)硅橡(xiang)膠(jiao)(jiao);按所用(yong)(yong)單體的不同,可分(fen)為甲基乙(yi)烯基硅橡(xiang)膠(jiao)(jiao),甲基苯基乙(yi)烯基硅橡(xiang)膠(jiao)(jiao)、氟硅,腈硅橡(xiang)膠(jiao)(jiao)等(deng);按性能和(he)用(yong)(yong)途的不同又可分(fen)為通用(yong)(yong)型(xing)、超耐(nai)低(di)溫型(xing)、超耐(nai)高(gao)溫型(xing)、高(gao)強力型(xing)、耐(nai)油型(xing)、醫用(yong)(yong)型(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)以(yi)三氯化鐵為(wei)催化劑合成的(de)(de)(de)。1945年(nian),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年(nian),采用(yong)高(gao)(gao)比表面積的(de)(de)(de)氣(qi)相(xiang)法白(bai)炭黑補強的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制(zhi)成功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)性能躍升到實用(yong)階段,奠定了(le)現(xian)代硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產技(ji)術的(de)(de)(de)基(ji)礎。從二(er)甲基(ji)二(er)氯硅(gui)(gui)(gui)烷合成開(kai)始生產硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)國(guo)家(jia)有美國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)工業化研(yan)究始于1957年(nian),多家(jia)研(yan)究所(suo)和企業陸(lu)續(xu)開(kai)發(fa)出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)底,中國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產能力為(wei)135千(qian)噸(dun),其中高(gao)(gao)溫膠(jiao)(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)硅橡膠(jiao)是指聚(ju)硅氧烷(wan)變成(cheng)彈性(xing)體的(de)過(guo)程是經過(guo)高(gao)溫(110-170℃)硫(liu)化(hua)成(cheng)型(xing)的(de)。它主要以高(gao)分(fen)子(zi)量的(de)聚(ju)甲基乙烯基硅氧烷(wan)為(wei)生膠(jiao),混入補強(qiang)填料(liao)、硫(liu)化(hua)劑(ji)等,在加(jia)熱加(jia)壓(ya)下(xia)硫(liu)化(hua)成(cheng)彈性(xing)體。硅橡膠(jiao)的(de)補強(qiang)主要是各(ge)種(zhong)(zhong)類型(xing)的(de)白(bai)炭(tan)黑(hei),可(ke)使硫(liu)化(hua)膠(jiao)的(de)強(qiang)度增加(jia)數十倍。有(you)(you)時(shi)為(wei)了(le)降低(di)成(cheng)本或改善膠(jiao)料(liao)性(xing)能及賦予硫(liu)化(hua)膠(jiao)各(ge)種(zhong)(zhong)特殊的(de)性(xing)能,也加(jia)入相應的(de)各(ge)種(zhong)(zhong)添加(jia)劑(ji)。硫(liu)化(hua)劑(ji)是各(ge)種(zhong)(zhong)有(you)(you)機過(guo)氧化(hua)物或加(jia)成(cheng)反應催化(hua)劑(ji)。
加工成型方法(fa)如(ru)圖所示。一(yi)次硫化(hua)(hua)的目的是(shi)進行(xing)(xing)高分子鏈的交聯(lian)反應;二次硫化(hua)(hua)的目的是(shi)進行(xing)(xing)補充交聯(lian)、驅除(chu)硫化(hua)(hua)劑分解(jie)產(chan)物(wu)和其他揮發性化(hua)(hua)合物(wu)以穩定硫化(hua)(hua)膠(jiao)的各項性能。常用的設(she)備有開放(fang)式煉膠(jiao)機、捏合機及真空(kong)密煉機。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特征(zheng)是(shi)高(gao)溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)溫(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)強度僅是(shi)天(tian)然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或(huo)某些合(he)成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)一(yi)半,但在(zai)(zai)200℃以上的(de)(de)高(gao)溫(wen)(wen)環(huan)境下,硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明(ming)顯變化(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃化(hua)溫(wen)(wen)度一(yi)般為-70~-50℃,特殊配方可達-100℃,表明(ming)其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)異。這對(dui)航空、宇航工業的(de)(de)意義重大。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及紫外線等十(shi)分穩定(ding),在(zai)(zai)不加任何添加劑(ji)(ji)的(de)(de)情況下,就具(ju)有優(you)良的(de)(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有優(you)異的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下的(de)(de)物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差(cha),但在(zai)(zai)150℃的(de)(de)高(gao)溫(wen)(wen)和(he)(he)-50℃的(de)(de)低(di)溫(wen)(wen)下,其(qi)物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)于通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐油及化(hua)學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有中等的(de)(de)耐油、耐溶(rong)劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)(qi)、氮、氧(yang)、二氧(yang)化(hua)碳等氣(qi)(qi)體(ti)的(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與(yu)人體(ti)組(zu)織不粘(zhan)連,具(ju)有抗(kang)凝血作(zuo)(zuo)用(yong),對(dui)肌體(ti)組(zu)織的(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特別適合(he)作(zuo)(zuo)為醫用(yong)材料。
硅橡膠的用量
據中國(guo)(guo)(guo)汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)產銷分(fen)別達到1927.18萬輛(liang)和(he)1930.64萬輛(liang),同比分(fen)別增長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)硅(gui)橡(xiang)膠(jiao)的(de)(de)用量約達2.0萬t。根據觀研(yan)天(tian)下的(de)(de)新研(yan)究,增加(jia)(jia)有機硅(gui)材(cai)料在汽(qi)(qi)(qi)車(che)零部件(jian)(jian)方面的(de)(de)用量,可以大幅度提高汽(qi)(qi)(qi)車(che)的(de)(de)安全性能(neng),因此,汽(qi)(qi)(qi)車(che)產量和(he)單(dan)車(che)用量水平的(de)(de)提高都(dou)將(jiang)推動汽(qi)(qi)(qi)車(che)工(gong)業(ye)(ye)對硅(gui)橡(xiang)膠(jiao)需(xu)求(qiu)的(de)(de)增加(jia)(jia)。國(guo)(guo)(guo)家(jia)鼓勵自(zi)主品牌(pai)(pai)的(de)(de)汽(qi)(qi)(qi)車(che)發(fa)展(zhan),關(guan)鍵汽(qi)(qi)(qi)車(che)零部件(jian)(jian)實現自(zi)主化,《2012年(nian)度黨政機關(guan)公務用車(che)選(xuan)用車(che)型目(mu)錄(征求(qiu)意見(jian)稿(gao))》為(wei)(wei)(wei)自(zi)主品牌(pai)(pai)擴大在政府采購(gou)的(de)(de)市場份額,為(wei)(wei)(wei)改(gai)變(bian)目(mu)前國(guo)(guo)(guo)內政府采購(gou)以合資品牌(pai)(pai)產品為(wei)(wei)(wei)主的(de)(de)局(ju)面提供了保(bao)障。促進自(zi)主品牌(pai)(pai)發(fa)展(zhan),國(guo)(guo)(guo)產汽(qi)(qi)(qi)車(che)業(ye)(ye)的(de)(de)繁榮將(jiang)為(wei)(wei)(wei)汽(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)應用提供有力保(bao)障。預測未來3年(nian),我國(guo)(guo)(guo)室溫硫化硅(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)車(che)行業(ye)(ye)將(jiang)以年(nian)均20%增長。
此外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)是重要(yao)的(de)(de)非石(shi)(shi)油(you)基(ji)合成橡(xiang)膠(jiao),約占非石(shi)(shi)油(you)基(ji)合成橡(xiang)膠(jiao)消(xiao)費(fei)量的(de)(de)98%。但(dan)因(yin)為石(shi)(shi)油(you)價格的(de)(de)大(da)幅(fu)上漲(zhang),同(tong)時(shi)我國(guo)在(zai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)關(guan)鍵(jian)原料有機(ji)硅(gui)(gui)(gui)單(dan)體的(de)(de)生產技(ji)術方面取得突破,有機(ji)硅(gui)(gui)(gui)單(dan)體的(de)(de)生產技(ji)術在(zai)2005年前被幾家跨國(guo)公司壟斷(duan),但(dan)目前我國(guo)已(yi)發展(zhan)成為全球有機(ji)硅(gui)(gui)(gui)單(dan)體第1大(da)國(guo),這(zhe)2個(ge)方面原因(yin)使硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)價格從2011年起開(kai)始低(di)于石(shi)(shi)油(you)基(ji)合成橡(xiang)膠(jiao),僅約為大(da)宗石(shi)(shi)油(you)基(ji)橡(xiang)膠(jiao)的(de)(de)80%~90%,成為廉價的(de)(de)合成橡(xiang)膠(jiao),并開(kai)始大(da)規(gui)模替代石(shi)(shi)油(you)基(ji)合成橡(xiang)膠(jiao)。這(zhe)將(jiang)極大(da)拓展(zhan)有機(ji)硅(gui)(gui)(gui)產業的(de)(de)市場空間,同(tong)時(shi)將(jiang)帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)(gui)樹脂等其他有機(ji)硅(gui)(gui)(gui)產品的(de)(de)消(xiao)費(fei)。