硅橡膠是(shi)指主鏈由硅(gui)(gui)和(he)氧(yang)(yang)原(yuan)子交(jiao)替構成(cheng),硅(gui)(gui)原(yuan)子上通(tong)常(chang)連(lian)有兩個(ge)有機基(ji)(ji)(ji)團的(de)(de)橡(xiang)膠(jiao)(jiao)。普通(tong)的(de)(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)主要由含甲基(ji)(ji)(ji)和(he)少(shao)量乙(yi)烯基(ji)(ji)(ji)的(de)(de)硅(gui)(gui)氧(yang)(yang)鏈節組成(cheng)。苯(ben)基(ji)(ji)(ji)的(de)(de)引入(ru)(ru)可提高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐高(gao)(gao)、低溫(wen)性(xing)(xing)(xing)(xing)能,三氟丙(bing)基(ji)(ji)(ji)及氰基(ji)(ji)(ji)的(de)(de)引入(ru)(ru)則可提高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐溫(wen)及耐油性(xing)(xing)(xing)(xing)能。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)耐低溫(wen)性(xing)(xing)(xing)(xing)能良好,一般(ban)在(zai)(zai)(zai)-55℃下仍能工作。引入(ru)(ru)苯(ben)基(ji)(ji)(ji)后,可達(da)-73℃。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐熱性(xing)(xing)(xing)(xing)能也很突出,在(zai)(zai)(zai)180℃下可長(chang)期工作,稍高(gao)(gao)于(yu)200℃也能承受(shou)數周或(huo)更長(chang)時間(jian)仍有彈性(xing)(xing)(xing)(xing),瞬(shun)時可耐300℃以上的(de)(de)高(gao)(gao)溫(wen)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)好,氧(yang)(yang)氣(qi)透過率在(zai)(zai)(zai)合成(cheng)聚合物中是(shi)較高(gao)(gao)的(de)(de)。此(ci)外(wai),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)還具有生理惰性(xing)(xing)(xing)(xing)、不(bu)會導致凝血的(de)(de)突出特性(xing)(xing)(xing)(xing),因此(ci)在(zai)(zai)(zai)醫(yi)用領域應(ying)用廣(guang)泛。
主要品種
硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)分(fen)(fen)類的(de)方法很(hen)多(duo),通常按(an)(an)固化前的(de)形態(tai)分(fen)(fen)為(wei)固體硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)和(he)液體硅(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)硫化溫(wen)度分(fen)(fen)為(wei)室溫(wen)硫化硅(gui)橡(xiang)膠(jiao)(jiao)(jiao),高溫(wen)硫化硅(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)所用(yong)單(dan)體的(de)不(bu)同(tong),可分(fen)(fen)為(wei)甲基(ji)(ji)(ji)乙(yi)烯(xi)基(ji)(ji)(ji)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲基(ji)(ji)(ji)苯基(ji)(ji)(ji)乙(yi)烯(xi)基(ji)(ji)(ji)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)等;按(an)(an)性能(neng)和(he)用(yong)途(tu)的(de)不(bu)同(tong)又可分(fen)(fen)為(wei)通用(yong)型(xing)(xing)、超耐低(di)溫(wen)型(xing)(xing)、超耐高溫(wen)型(xing)(xing)、高強力型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)以(yi)三氯化鐵為催化劑合成的。1945年(nian),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年(nian),采(cai)用高比表面積的氣相法白炭黑(hei)補強的硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研制成功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的性能(neng)躍升(sheng)到(dao)實(shi)用階(jie)段(duan),奠定了現代(dai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產技(ji)術的基礎。從(cong)二甲基二氯硅(gui)(gui)(gui)烷(wan)合成開始生產硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中國(guo)等(deng)。中國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的工業化研究始于1957年(nian),多家研究所和企業陸續開發出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底(di),中國(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產能(neng)力為135千噸,其中高溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)化硅(gui)橡(xiang)膠是(shi)指聚硅(gui)氧烷變成(cheng)彈性體的(de)(de)(de)過程是(shi)經過高溫(110-170℃)硫(liu)化成(cheng)型的(de)(de)(de)。它主(zhu)要(yao)以高分子(zi)量的(de)(de)(de)聚甲(jia)基乙烯(xi)基硅(gui)氧烷為生膠,混入補強(qiang)填料(liao)、硫(liu)化劑(ji)等,在加(jia)熱加(jia)壓下硫(liu)化成(cheng)彈性體。硅(gui)橡(xiang)膠的(de)(de)(de)補強(qiang)主(zhu)要(yao)是(shi)各(ge)種類型的(de)(de)(de)白炭黑(hei),可使硫(liu)化膠的(de)(de)(de)強(qiang)度增(zeng)加(jia)數十(shi)倍。有時為了降低成(cheng)本(ben)或改善膠料(liao)性能(neng)及(ji)賦予(yu)硫(liu)化膠各(ge)種特(te)殊(shu)的(de)(de)(de)性能(neng),也加(jia)入相應的(de)(de)(de)各(ge)種添加(jia)劑(ji)。硫(liu)化劑(ji)是(shi)各(ge)種有機過氧化物或加(jia)成(cheng)反(fan)應催(cui)化劑(ji)。
加工(gong)成型方法(fa)如圖所示(shi)。一次硫(liu)(liu)(liu)化(hua)的(de)目的(de)是進行(xing)高分(fen)子鏈的(de)交聯反(fan)應(ying);二次硫(liu)(liu)(liu)化(hua)的(de)目的(de)是進行(xing)補(bu)充交聯、驅除硫(liu)(liu)(liu)化(hua)劑分(fen)解產物和其他揮發性化(hua)合物以(yi)穩定(ding)硫(liu)(liu)(liu)化(hua)膠的(de)各(ge)項(xiang)性能。常用的(de)設備(bei)有(you)開放式煉(lian)膠機(ji)(ji)、捏合機(ji)(ji)及真空密煉(lian)機(ji)(ji)。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特(te)(te)(te)征是(shi)高溫(wen)(wen)(wen)(wen)穩定(ding)(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)(chang)溫(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)僅(jin)是(shi)天然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些(xie)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半,但(dan)在200℃以(yi)上的(de)(de)高溫(wen)(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)保持一定(ding)(ding)(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)(biao)面(mian)硬度(du),且力學(xue)(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明顯變(bian)化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度(du)一般為-70~-50℃,特(te)(te)(te)殊配方(fang)可達-100℃,表(biao)(biao)明其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這(zhe)對航(hang)空(kong)(kong)、宇航(hang)工(gong)業的(de)(de)意(yi)義重大(da)。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)、臭氧(yang)及紫外(wai)線等十(shi)分穩定(ding)(ding)(ding),在不加(jia)任何添(tian)加(jia)劑的(de)(de)情況(kuang)下,就(jiu)具(ju)(ju)有(you)優(you)良的(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)(chang)好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)(chang)(chang)溫(wen)(wen)(wen)(wen)下的(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差(cha),但(dan)在150℃的(de)(de)高溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)(wen)(wen)下,其物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及化學(xue)(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)中(zhong)等的(de)(de)耐(nai)油(you)、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空(kong)(kong)氣(qi)、氮、氧(yang)、二氧(yang)化碳(tan)等氣(qi)體的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生(sheng)理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人體組織(zhi)不粘連,具(ju)(ju)有(you)抗(kang)凝血作用(yong),對肌體組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)(chang)少。特(te)(te)(te)別適(shi)合(he)作為醫用(yong)材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)協會統(tong)計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車(che)(che)產(chan)(chan)銷(xiao)分(fen)別達(da)到1927.18萬(wan)輛(liang)和(he)1930.64萬(wan)輛(liang),同比分(fen)別增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)硅橡膠的(de)(de)用(yong)(yong)(yong)量約達(da)2.0萬(wan)t。根據觀(guan)研天(tian)下的(de)(de)新研究,增(zeng)加有機(ji)硅材(cai)料在(zai)(zai)(zai)汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)(ling)部件方面(mian)的(de)(de)用(yong)(yong)(yong)量,可以大幅度(du)提高汽(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)安(an)全性能,因此,汽(qi)(qi)(qi)(qi)車(che)(che)產(chan)(chan)量和(he)單(dan)車(che)(che)用(yong)(yong)(yong)量水平的(de)(de)提高都將推動(dong)汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)對(dui)硅橡膠需(xu)求(qiu)的(de)(de)增(zeng)加。國家鼓勵自(zi)主(zhu)品(pin)牌(pai)的(de)(de)汽(qi)(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)(ling)部件實現(xian)自(zi)主(zhu)化(hua),《2012年(nian)(nian)度(du)黨政(zheng)機(ji)關公務用(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)車(che)(che)型目錄(征(zheng)求(qiu)意見稿(gao))》為自(zi)主(zhu)品(pin)牌(pai)擴大在(zai)(zai)(zai)政(zheng)府(fu)(fu)采購的(de)(de)市場份額,為改變目前國內政(zheng)府(fu)(fu)采購以合資品(pin)牌(pai)產(chan)(chan)品(pin)為主(zhu)的(de)(de)局面(mian)提供(gong)了(le)保障(zhang)。促進自(zi)主(zhu)品(pin)牌(pai)發展,國產(chan)(chan)汽(qi)(qi)(qi)(qi)車(che)(che)業(ye)(ye)(ye)的(de)(de)繁榮將為汽(qi)(qi)(qi)(qi)車(che)(che)膠的(de)(de)應(ying)用(yong)(yong)(yong)提供(gong)有力(li)保障(zhang)。預(yu)測未來3年(nian)(nian),我國室溫硫化(hua)硅橡膠在(zai)(zai)(zai)汽(qi)(qi)(qi)(qi)車(che)(che)行業(ye)(ye)(ye)將以年(nian)(nian)均(jun)20%增(zeng)長。
此(ci)外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重(zhong)要的非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消費量(liang)的98%。但因(yin)為石(shi)(shi)油(you)價(jia)(jia)格的大(da)幅上漲,同時我國(guo)在硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的關鍵(jian)原料有(you)機(ji)(ji)硅(gui)單體的生產(chan)(chan)技術方面取得突破,有(you)機(ji)(ji)硅(gui)單體的生產(chan)(chan)技術在2005年前被幾家跨國(guo)公司壟斷,但目前我國(guo)已發展(zhan)成(cheng)(cheng)(cheng)(cheng)(cheng)為全球有(you)機(ji)(ji)硅(gui)單體第1大(da)國(guo),這(zhe)2個方面原因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的價(jia)(jia)格從(cong)2011年起開(kai)始(shi)低于石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約為大(da)宗石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)(cheng)(cheng)(cheng)(cheng)為廉價(jia)(jia)的合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開(kai)始(shi)大(da)規模(mo)替代(dai)石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這(zhe)將(jiang)極大(da)拓展(zhan)有(you)機(ji)(ji)硅(gui)產(chan)(chan)業的市場空間,同時將(jiang)帶動硅(gui)油(you)、硅(gui)烷偶聯劑(ji)和硅(gui)樹(shu)脂(zhi)等其他有(you)機(ji)(ji)硅(gui)產(chan)(chan)品的消費。