
硅橡膠是(shi)指主鏈由(you)硅(gui)(gui)和氧(yang)原子(zi)交替構成,硅(gui)(gui)原子(zi)上(shang)通常(chang)連有(you)兩(liang)個有(you)機基團(tuan)的橡(xiang)(xiang)膠(jiao)。普通的硅(gui)(gui)橡(xiang)(xiang)膠(jiao)主要由(you)含甲(jia)基和少(shao)量(liang)乙烯基的硅(gui)(gui)氧(yang)鏈節組成。苯基的引(yin)入(ru)可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)高(gao)(gao)、低溫(wen)性能(neng),三(san)氟丙基及(ji)氰基的引(yin)入(ru)則可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)溫(wen)及(ji)耐(nai)油性能(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)耐(nai)低溫(wen)性能(neng)良好,一(yi)般在(zai)-55℃下仍(reng)(reng)能(neng)工作。引(yin)入(ru)苯基后,可達-73℃。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)熱性能(neng)也很突(tu)出(chu),在(zai)180℃下可長期工作,稍高(gao)(gao)于200℃也能(neng)承受數周或更長時(shi)間仍(reng)(reng)有(you)彈性,瞬時(shi)可耐(nai)300℃以上(shang)的高(gao)(gao)溫(wen)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的透氣性好,氧(yang)氣透過率在(zai)合(he)成聚合(he)物中(zhong)是(shi)較高(gao)(gao)的。此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)還具(ju)有(you)生理(li)惰性、不會導(dao)致凝血的突(tu)出(chu)特性,因此在(zai)醫用領(ling)域應用廣(guang)泛。
主要品種
硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)分類的方(fang)法很多,通常按(an)(an)(an)固(gu)化前的形態分為固(gu)體硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)和(he)液(ye)體硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)(an)硫化溫度分為室溫硫化硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)溫硫化硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)(an)所用(yong)單(dan)體的不(bu)同,可分為甲(jia)基(ji)乙烯基(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),甲(jia)基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui)(gui)(gui)(gui)(gui)(gui),腈硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)(an)(an)性能和(he)用(yong)途的不(bu)同又可分為通用(yong)型(xing)(xing)(xing)、超耐低溫型(xing)(xing)(xing)、超耐高(gao)溫型(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)橡(xiang)(xiang)膠早(zao)期是(shi)由美國(guo)以(yi)三(san)氯化鐵為催(cui)化劑合(he)成的。1945年(nian)(nian),硅(gui)(gui)橡(xiang)(xiang)膠產品(pin)問世。1948年(nian)(nian),采用(yong)高比表面積的氣相(xiang)法白炭(tan)黑補強的硅(gui)(gui)橡(xiang)(xiang)膠研(yan)制成功,使硅(gui)(gui)橡(xiang)(xiang)膠的性(xing)能躍升(sheng)到(dao)(dao)實用(yong)階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)膠生(sheng)產技術的基(ji)礎(chu)。從二甲(jia)基(ji)二氯硅(gui)(gui)烷合(he)成開始生(sheng)產硅(gui)(gui)橡(xiang)(xiang)膠的國(guo)家有(you)美國(guo)。俄羅斯、德(de)國(guo)、日本、韓國(guo)和(he)中(zhong)國(guo)等(deng)。中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠的工業(ye)化研(yan)究始于1957年(nian)(nian),多家研(yan)究所和(he)企業(ye)陸續開發出各種硅(gui)(gui)橡(xiang)(xiang)膠。到(dao)(dao)2003年(nian)(nian)底,中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠生(sheng)產能力為135千噸(dun),其中(zhong)高溫膠100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)硅橡(xiang)膠(jiao)是(shi)指聚(ju)硅氧烷變成彈性(xing)體的過程是(shi)經過高溫(110-170℃)硫(liu)(liu)化(hua)(hua)成型的。它主(zhu)要(yao)以高分子量(liang)的聚(ju)甲基乙烯基硅氧烷為(wei)生膠(jiao),混入補強填料、硫(liu)(liu)化(hua)(hua)劑(ji)等,在加熱加壓下硫(liu)(liu)化(hua)(hua)成彈性(xing)體。硅橡(xiang)膠(jiao)的補強主(zhu)要(yao)是(shi)各種類(lei)型的白炭(tan)黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)的強度(du)增加數(shu)十倍。有(you)時為(wei)了(le)降低成本(ben)或改善膠(jiao)料性(xing)能及賦予(yu)硫(liu)(liu)化(hua)(hua)膠(jiao)各種特殊的性(xing)能,也加入相應的各種添(tian)加劑(ji)。硫(liu)(liu)化(hua)(hua)劑(ji)是(shi)各種有(you)機過氧化(hua)(hua)物或加成反應催化(hua)(hua)劑(ji)。
加工成型方法如圖所(suo)示。一次硫(liu)化的(de)目的(de)是進行(xing)高分(fen)子鏈的(de)交聯(lian)反應;二次硫(liu)化的(de)目的(de)是進行(xing)補充交聯(lian)、驅除硫(liu)化劑分(fen)解產(chan)物和(he)其他揮發性化合物以穩定(ding)硫(liu)化膠的(de)各項性能(neng)。常用的(de)設備有(you)開放(fang)式煉膠機、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)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特(te)征(zheng)是(shi)高(gao)溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅(jin)是(shi)天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但在(zai)(zai)200℃以(yi)上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)(wu)明顯變化。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)度(du)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)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)異(yi)。這對航空、宇(yu)航工(gong)業的(de)(de)(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中(zhong)Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及紫外線等(deng)十分穩定(ding),在(zai)(zai)不加任何添加劑的(de)(de)(de)(de)(de)情況(kuang)下,就(jiu)具(ju)(ju)有優(you)良的(de)(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有優(you)異(yi)的(de)(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好(hao)。(5)物(wu)理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)(wen)下的(de)(de)(de)(de)(de)物(wu)理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)和-50℃的(de)(de)(de)(de)(de)低(di)溫(wen)(wen)下,其物(wu)理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)于通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)油及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有中(zhong)等(deng)的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對空氣(qi)(qi)(qi)、氮(dan)、氧(yang)(yang)、二氧(yang)(yang)化碳等(deng)氣(qi)(qi)(qi)體的(de)(de)(de)(de)(de)透(tou)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人體組織不粘連(lian),具(ju)(ju)有抗凝血作(zuo)用(yong),對肌體組織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少(shao)。特(te)別適合作(zuo)為醫用(yong)材料。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)車(che)(che)(che)工業協會統(tong)計,2012年(nian),汽(qi)(qi)車(che)(che)(che)產(chan)銷分別(bie)達到1927.18萬輛(liang)和(he)(he)1930.64萬輛(liang),同比分別(bie)增(zeng)長4.63%和(he)(he)4.33%,汽(qi)(qi)車(che)(che)(che)工業硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)用(yong)(yong)量(liang)(liang)約(yue)達2.0萬t。根(gen)據(ju)觀研(yan)天下的(de)(de)(de)新研(yan)究,增(zeng)加有(you)(you)機硅材料(liao)在(zai)汽(qi)(qi)車(che)(che)(che)零(ling)(ling)部件方面(mian)的(de)(de)(de)用(yong)(yong)量(liang)(liang),可以大(da)幅度(du)提(ti)高汽(qi)(qi)車(che)(che)(che)的(de)(de)(de)安全(quan)性能(neng),因此,汽(qi)(qi)車(che)(che)(che)產(chan)量(liang)(liang)和(he)(he)單車(che)(che)(che)用(yong)(yong)量(liang)(liang)水(shui)平的(de)(de)(de)提(ti)高都將(jiang)推(tui)動(dong)汽(qi)(qi)車(che)(che)(che)工業對硅橡(xiang)膠(jiao)(jiao)需求(qiu)的(de)(de)(de)增(zeng)加。國(guo)家鼓勵自主(zhu)品(pin)牌(pai)的(de)(de)(de)汽(qi)(qi)車(che)(che)(che)發展,關鍵汽(qi)(qi)車(che)(che)(che)零(ling)(ling)部件實現自主(zhu)化,《2012年(nian)度(du)黨(dang)政(zheng)機關公務用(yong)(yong)車(che)(che)(che)選用(yong)(yong)車(che)(che)(che)型目(mu)錄(征求(qiu)意見稿(gao))》為(wei)(wei)自主(zhu)品(pin)牌(pai)擴大(da)在(zai)政(zheng)府(fu)采購的(de)(de)(de)市場份額,為(wei)(wei)改變目(mu)前國(guo)內政(zheng)府(fu)采購以合資品(pin)牌(pai)產(chan)品(pin)為(wei)(wei)主(zhu)的(de)(de)(de)局面(mian)提(ti)供了保障。促進自主(zhu)品(pin)牌(pai)發展,國(guo)產(chan)汽(qi)(qi)車(che)(che)(che)業的(de)(de)(de)繁榮將(jiang)為(wei)(wei)汽(qi)(qi)車(che)(che)(che)膠(jiao)(jiao)的(de)(de)(de)應用(yong)(yong)提(ti)供有(you)(you)力保障。預測未來3年(nian),我(wo)國(guo)室溫硫化硅橡(xiang)膠(jiao)(jiao)在(zai)汽(qi)(qi)車(che)(che)(che)行業將(jiang)以年(nian)均(jun)20%增(zeng)長。
此外(wai),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)是(shi)重要的(de)非石(shi)(shi)油基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非石(shi)(shi)油基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消費(fei)(fei)量的(de)98%。但因(yin)為石(shi)(shi)油價(jia)(jia)格的(de)大幅上(shang)漲,同(tong)時我(wo)國(guo)在硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)關鍵原(yuan)料有機(ji)硅(gui)單體的(de)生產(chan)(chan)技術方(fang)面(mian)取得(de)突(tu)破,有機(ji)硅(gui)單體的(de)生產(chan)(chan)技術在2005年前被(bei)幾家(jia)跨國(guo)公司壟斷,但目前我(wo)國(guo)已發展成(cheng)為全球有機(ji)硅(gui)單體第(di)1大國(guo),這2個方(fang)面(mian)原(yuan)因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)價(jia)(jia)格從2011年起開始低于石(shi)(shi)油基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約為大宗(zong)石(shi)(shi)油基(ji)橡(xiang)(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)為廉價(jia)(jia)的(de)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開始大規模替代石(shi)(shi)油基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將(jiang)(jiang)極大拓展有機(ji)硅(gui)產(chan)(chan)業(ye)的(de)市場空間,同(tong)時將(jiang)(jiang)帶動硅(gui)油、硅(gui)烷(wan)偶(ou)聯劑和(he)硅(gui)樹脂等(deng)其他有機(ji)硅(gui)產(chan)(chan)品的(de)消費(fei)(fei)。