
硅橡膠是指主鏈由硅和氧原子交替構成(cheng)(cheng),硅原子上通(tong)常連有(you)兩(liang)個有(you)機基(ji)(ji)團的(de)(de)橡(xiang)膠(jiao)。普通(tong)的(de)(de)硅橡(xiang)膠(jiao)主要由含甲(jia)基(ji)(ji)和少量(liang)乙烯基(ji)(ji)的(de)(de)硅氧鏈節組(zu)成(cheng)(cheng)。苯基(ji)(ji)的(de)(de)引入可提高硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)高、低溫(wen)性(xing)(xing)(xing)能,三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則可提高硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)(xing)(xing)能。硅橡(xiang)膠(jiao)耐(nai)(nai)低溫(wen)性(xing)(xing)(xing)能良好,一(yi)般在(zai)-55℃下(xia)仍能工(gong)作。引入苯基(ji)(ji)后,可達-73℃。硅橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)熱性(xing)(xing)(xing)能也很(hen)突出,在(zai)180℃下(xia)可長(chang)期工(gong)作,稍高于200℃也能承受數周或(huo)更長(chang)時間(jian)仍有(you)彈性(xing)(xing)(xing),瞬(shun)時可耐(nai)(nai)300℃以上的(de)(de)高溫(wen)。硅橡(xiang)膠(jiao)的(de)(de)透(tou)(tou)氣(qi)性(xing)(xing)(xing)好,氧氣(qi)透(tou)(tou)過率在(zai)合成(cheng)(cheng)聚合物中是較高的(de)(de)。此外,硅橡(xiang)膠(jiao)還(huan)具有(you)生理惰性(xing)(xing)(xing)、不會導致凝(ning)血的(de)(de)突出特性(xing)(xing)(xing),因此在(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)分(fen)類(lei)的(de)(de)方法很多,通(tong)常按(an)固(gu)化前的(de)(de)形態分(fen)為固(gu)體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)和(he)液體硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)硫化溫(wen)度分(fen)為室溫(wen)硫化硅(gui)(gui)橡(xiang)(xiang)膠(jiao),高溫(wen)硫化硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)所用(yong)單體的(de)(de)不(bu)同,可(ke)分(fen)為甲基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)、氟(fu)硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)膠(jiao)等;按(an)性能和(he)用(yong)途的(de)(de)不(bu)同又可(ke)分(fen)為通(tong)用(yong)型(xing)、超耐低溫(wen)型(xing)、超耐高溫(wen)型(xing)、高強力型(xing)、耐油型(xing)、醫用(yong)型(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)早期是(shi)由美國(guo)以(yi)三氯化(hua)鐵為(wei)催化(hua)劑合(he)成(cheng)的(de)。1945年(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)產(chan)(chan)品問世(shi)。1948年(nian),采用高比表面積的(de)氣相法(fa)白(bai)炭(tan)黑(hei)補強的(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)性(xing)能躍升(sheng)到(dao)(dao)實(shi)用階段,奠定了現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產(chan)(chan)技(ji)術的(de)基礎(chu)。從二(er)甲基二(er)氯硅(gui)烷(wan)合(he)成(cheng)開始(shi)生產(chan)(chan)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)國(guo)家(jia)有(you)美國(guo)。俄羅斯(si)、德國(guo)、日本、韓(han)國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)工(gong)業(ye)化(hua)研(yan)究(jiu)始(shi)于1957年(nian),多家(jia)研(yan)究(jiu)所和企業(ye)陸續(xu)開發出各種硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。到(dao)(dao)2003年(nian)底,中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產(chan)(chan)能力(li)為(wei)135千(qian)噸,其中(zhong)高溫(wen)膠(jiao)(jiao)(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)(gao)溫(wen)(wen)硫(liu)(liu)化(hua)(hua)硅橡膠(jiao)是(shi)(shi)(shi)指聚(ju)硅氧烷變(bian)成(cheng)彈性體的過程是(shi)(shi)(shi)經過高(gao)(gao)溫(wen)(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)型的。它主要以高(gao)(gao)分子量的聚(ju)甲基乙烯(xi)基硅氧烷為生膠(jiao),混(hun)入(ru)補強填料(liao)、硫(liu)(liu)化(hua)(hua)劑等,在加(jia)熱(re)加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)彈性體。硅橡膠(jiao)的補強主要是(shi)(shi)(shi)各(ge)種類(lei)型的白炭黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)的強度增(zeng)加(jia)數十倍。有(you)時為了(le)降低成(cheng)本或(huo)改善膠(jiao)料(liao)性能(neng)及賦予硫(liu)(liu)化(hua)(hua)膠(jiao)各(ge)種特殊(shu)的性能(neng),也加(jia)入(ru)相應(ying)的各(ge)種添加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是(shi)(shi)(shi)各(ge)種有(you)機過氧化(hua)(hua)物或(huo)加(jia)成(cheng)反應(ying)催化(hua)(hua)劑。
加工成型方(fang)法如圖所示。一(yi)次硫(liu)化的(de)(de)目(mu)的(de)(de)是進行(xing)高分(fen)子鏈的(de)(de)交聯反應;二(er)次硫(liu)化的(de)(de)目(mu)的(de)(de)是進行(xing)補充交聯、驅除硫(liu)化劑分(fen)解產物和其他揮發性化合(he)(he)物以穩定硫(liu)化膠(jiao)的(de)(de)各項性能。常(chang)用的(de)(de)設備有開(kai)放式煉(lian)膠(jiao)機、捏合(he)(he)機及真空(kong)密煉(lian)機。
主要性能
(1)高溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)特征是(shi)高溫穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常(chang)溫下硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)強(qiang)度僅(jin)是(shi)天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)一半(ban),但在200℃以上的(de)高溫環境下,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)保持一定(ding)(ding)的(de)柔(rou)韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度,且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)無(wu)明顯(xian)變化(hua)。(2)低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)玻(bo)璃化(hua)溫度一般(ban)為-70~-50℃,特殊配方可達-100℃,表明其低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)異。這對(dui)航空、宇(yu)航工業的(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧、臭氧及紫外線(xian)等(deng)十分穩定(ding)(ding),在不(bu)加(jia)任(ren)何添加(jia)劑的(de)情況(kuang)下,就具(ju)有(you)優(you)(you)良的(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)優(you)(you)異的(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫下的(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)比通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)高溫和(he)-50℃的(de)低(di)(di)溫下,其物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)于通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)油及化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)的(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。(7)氣(qi)(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。室溫下硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣(qi)(qi)、氮、氧、二(er)氧化(hua)碳(tan)等(deng)氣(qi)(qi)體的(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)高出30-50倍。(8)生(sheng)理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅,與(yu)人體組織(zhi)不(bu)粘連,具(ju)有(you)抗(kang)凝血作用(yong),對(dui)肌體組織(zhi)的(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特別適(shi)合作為醫用(yong)材(cai)料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)協會(hui)統計,2012年,汽(qi)(qi)(qi)車(che)(che)產(chan)銷分別(bie)達(da)到1927.18萬(wan)輛(liang)(liang)和(he)1930.64萬(wan)輛(liang)(liang),同比(bi)分別(bie)增長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)硅(gui)(gui)橡膠(jiao)(jiao)的用(yong)(yong)(yong)量約(yue)達(da)2.0萬(wan)t。根據觀研天下的新研究(jiu),增加(jia)有機硅(gui)(gui)材料在(zai)汽(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件方面的用(yong)(yong)(yong)量,可以(yi)(yi)大幅度提(ti)(ti)高汽(qi)(qi)(qi)車(che)(che)的安全(quan)性能,因此,汽(qi)(qi)(qi)車(che)(che)產(chan)量和(he)單車(che)(che)用(yong)(yong)(yong)量水(shui)平的提(ti)(ti)高都將推(tui)動汽(qi)(qi)(qi)車(che)(che)工業(ye)(ye)對硅(gui)(gui)橡膠(jiao)(jiao)需求的增加(jia)。國(guo)(guo)家(jia)鼓勵(li)自(zi)主(zhu)(zhu)品(pin)(pin)牌的汽(qi)(qi)(qi)車(che)(che)發(fa)展,關鍵汽(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件實現自(zi)主(zhu)(zhu)化(hua)(hua),《2012年度黨政機關公務用(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)車(che)(che)型目錄(征(zheng)求意見稿)》為(wei)自(zi)主(zhu)(zhu)品(pin)(pin)牌擴(kuo)大在(zai)政府(fu)采(cai)購(gou)的市場份額,為(wei)改變目前國(guo)(guo)內政府(fu)采(cai)購(gou)以(yi)(yi)合資品(pin)(pin)牌產(chan)品(pin)(pin)為(wei)主(zhu)(zhu)的局(ju)面提(ti)(ti)供了保(bao)障(zhang)。促進自(zi)主(zhu)(zhu)品(pin)(pin)牌發(fa)展,國(guo)(guo)產(chan)汽(qi)(qi)(qi)車(che)(che)業(ye)(ye)的繁榮將為(wei)汽(qi)(qi)(qi)車(che)(che)膠(jiao)(jiao)的應用(yong)(yong)(yong)提(ti)(ti)供有力保(bao)障(zhang)。預(yu)測未來3年,我國(guo)(guo)室溫硫化(hua)(hua)硅(gui)(gui)橡膠(jiao)(jiao)在(zai)汽(qi)(qi)(qi)車(che)(che)行業(ye)(ye)將以(yi)(yi)年均20%增長(chang)。
此外(wai),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)是重(zhong)要(yao)的(de)(de)非石油(you)基(ji)合(he)成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非石油(you)基(ji)合(he)成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消(xiao)費量的(de)(de)98%。但因為石油(you)價(jia)格的(de)(de)大(da)幅上漲,同時(shi)(shi)我國(guo)在硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)關鍵原料有機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)的(de)(de)生(sheng)產(chan)(chan)技術(shu)方(fang)面(mian)取得(de)突破,有機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)的(de)(de)生(sheng)產(chan)(chan)技術(shu)在2005年前(qian)(qian)被(bei)幾家跨國(guo)公司壟斷(duan),但目前(qian)(qian)我國(guo)已(yi)發(fa)展成(cheng)(cheng)(cheng)(cheng)為全球有機(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)第(di)1大(da)國(guo),這2個(ge)方(fang)面(mian)原因使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)價(jia)格從2011年起開始(shi)低于石油(you)基(ji)合(he)成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅(jin)約為大(da)宗石油(you)基(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)(cheng)(cheng)為廉價(jia)的(de)(de)合(he)成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開始(shi)大(da)規模(mo)替(ti)代石油(you)基(ji)合(he)成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將極大(da)拓展有機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)(chan)業的(de)(de)市場空間,同時(shi)(shi)將帶動硅(gui)(gui)(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)(gui)(gui)樹脂(zhi)等其(qi)他有機(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)(chan)品的(de)(de)消(xiao)費。