
硅橡膠是指主(zhu)鏈由(you)硅(gui)(gui)(gui)(gui)(gui)和氧原子(zi)交(jiao)替構成(cheng),硅(gui)(gui)(gui)(gui)(gui)原子(zi)上通常連有(you)兩個有(you)機基(ji)(ji)團的(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)。普通的(de)(de)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)主(zhu)要由(you)含甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)(de)硅(gui)(gui)(gui)(gui)(gui)氧鏈節組成(cheng)。苯基(ji)(ji)的(de)(de)引入可(ke)提高(gao)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐高(gao)、低溫(wen)性(xing)(xing)(xing)能(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則可(ke)提高(gao)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐溫(wen)及耐油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)耐低溫(wen)性(xing)(xing)(xing)能(neng)良好,一般在(zai)(zai)-55℃下(xia)仍能(neng)工(gong)作。引入苯基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)耐熱(re)性(xing)(xing)(xing)能(neng)也很突出(chu),在(zai)(zai)180℃下(xia)可(ke)長(chang)期(qi)工(gong)作,稍(shao)高(gao)于200℃也能(neng)承(cheng)受數周或更長(chang)時間仍有(you)彈(dan)性(xing)(xing)(xing),瞬時可(ke)耐300℃以上的(de)(de)高(gao)溫(wen)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)透氣性(xing)(xing)(xing)好,氧氣透過率在(zai)(zai)合成(cheng)聚合物中(zhong)是較高(gao)的(de)(de)。此(ci)(ci)外,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)還具有(you)生理惰性(xing)(xing)(xing)、不會(hui)導致凝(ning)血的(de)(de)突出(chu)特性(xing)(xing)(xing),因(yin)此(ci)(ci)在(zai)(zai)醫用(yong)領域應用(yong)廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)分類的方法(fa)很多,通(tong)常按(an)固化前的形態分為(wei)固體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)和(he)液體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)硫化溫(wen)度(du)分為(wei)室溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),高溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)所用(yong)(yong)單體的不(bu)(bu)同(tong),可分為(wei)甲基(ji)乙(yi)烯(xi)基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙(yi)烯(xi)基(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)等;按(an)性能和(he)用(yong)(yong)途的不(bu)(bu)同(tong)又(you)可分為(wei)通(tong)用(yong)(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)(yong)型(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠早期是由美國(guo)(guo)(guo)(guo)(guo)以三(san)氯化鐵(tie)為催化劑(ji)合成(cheng)的(de)。1945年,硅(gui)橡(xiang)(xiang)膠產(chan)(chan)(chan)品(pin)問世。1948年,采用高(gao)比表面積的(de)氣相法白(bai)炭黑(hei)補強的(de)硅(gui)橡(xiang)(xiang)膠研(yan)制成(cheng)功,使硅(gui)橡(xiang)(xiang)膠的(de)性能(neng)躍升(sheng)到(dao)實用階段,奠定了現代(dai)硅(gui)橡(xiang)(xiang)膠生產(chan)(chan)(chan)技(ji)術(shu)的(de)基礎。從(cong)二(er)甲基二(er)氯硅(gui)烷(wan)合成(cheng)開(kai)始生產(chan)(chan)(chan)硅(gui)橡(xiang)(xiang)膠的(de)國(guo)(guo)(guo)(guo)(guo)家有美國(guo)(guo)(guo)(guo)(guo)。俄羅斯、德國(guo)(guo)(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)(guo)(guo)和(he)中(zhong)國(guo)(guo)(guo)(guo)(guo)等(deng)。中(zhong)國(guo)(guo)(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠的(de)工業化研(yan)究(jiu)始于1957年,多家研(yan)究(jiu)所和(he)企業陸續(xu)開(kai)發出各種硅(gui)橡(xiang)(xiang)膠。到(dao)2003年底,中(zhong)國(guo)(guo)(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠生產(chan)(chan)(chan)能(neng)力為135千(qian)噸,其中(zhong)高(gao)溫膠100千(qian)噸。
高溫硫化硅橡膠
高溫硫化(hua)(hua)硅橡膠(jiao)是(shi)指聚硅氧烷變成彈性(xing)體的過程是(shi)經過高溫(110-170℃)硫化(hua)(hua)成型(xing)(xing)的。它主要以高分子(zi)量的聚甲基乙(yi)烯基硅氧烷為生膠(jiao),混入(ru)補(bu)強(qiang)填料、硫化(hua)(hua)劑(ji)等,在(zai)加熱加壓下(xia)硫化(hua)(hua)成彈性(xing)體。硅橡膠(jiao)的補(bu)強(qiang)主要是(shi)各(ge)(ge)種(zhong)類型(xing)(xing)的白炭黑,可(ke)使硫化(hua)(hua)膠(jiao)的強(qiang)度增加數十倍。有時為了降低(di)成本或改善膠(jiao)料性(xing)能及賦予硫化(hua)(hua)膠(jiao)各(ge)(ge)種(zhong)特殊的性(xing)能,也加入(ru)相應(ying)的各(ge)(ge)種(zhong)添(tian)加劑(ji)。硫化(hua)(hua)劑(ji)是(shi)各(ge)(ge)種(zhong)有機過氧化(hua)(hua)物或加成反應(ying)催化(hua)(hua)劑(ji)。
加工成型方法如圖所示。一(yi)次硫化的目(mu)(mu)的是進行(xing)高(gao)分子(zi)鏈的交聯反應;二次硫化的目(mu)(mu)的是進行(xing)補充交聯、驅除硫化劑分解產物(wu)和其他揮發性化合(he)物(wu)以(yi)穩定硫化膠(jiao)的各項(xiang)性能。常(chang)用(yong)的設備有(you)開放式煉(lian)膠(jiao)機(ji)、捏合(he)機(ji)及真空(kong)密煉(lian)機(ji)。
主要性能
(1)高(gao)溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)特(te)(te)征(zheng)是(shi)高(gao)溫穩定性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)強(qiang)度僅(jin)是(shi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)一半,但在200℃以上的(de)(de)(de)(de)高(gao)溫環境下,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持一定的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無明顯變化。(2)低溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)玻璃化溫度一般(ban)為(wei)-70~-50℃,特(te)(te)殊配方(fang)可(ke)達-100℃,表明其低溫性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異(yi)。這(zhe)對(dui)航空、宇航工業的(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭(chou)氧(yang)及紫(zi)外(wai)線等(deng)十分(fen)穩定,在不(bu)加任(ren)何添(tian)加劑的(de)(de)(de)(de)情況下,就具有優良的(de)(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具有優異(yi)的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫下的(de)(de)(de)(de)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差(cha),但在150℃的(de)(de)(de)(de)高(gao)溫和-50℃的(de)(de)(de)(de)低溫下,其物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油及化學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具有中等(deng)的(de)(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)、二(er)氧(yang)化碳等(deng)氣(qi)體的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無毒,無味(wei),無嗅,與人體組織不(bu)粘連,具有抗凝血作用(yong)(yong),對(dui)肌體組織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)(te)別(bie)適合作為(wei)醫(yi)用(yong)(yong)材料。
硅橡膠的用量
據中(zhong)國(guo)汽(qi)(qi)(qi)車(che)(che)(che)工(gong)(gong)業協會(hui)統計,2012年(nian),汽(qi)(qi)(qi)車(che)(che)(che)產(chan)(chan)銷分(fen)別達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分(fen)別增(zeng)長(chang)(chang)4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)(che)工(gong)(gong)業硅橡膠的(de)用(yong)(yong)量(liang)約達2.0萬t。根據觀(guan)研天下的(de)新研究,增(zeng)加(jia)有(you)機硅材料在(zai)汽(qi)(qi)(qi)車(che)(che)(che)零部件(jian)方(fang)面的(de)用(yong)(yong)量(liang),可以(yi)大(da)幅度(du)提(ti)高(gao)汽(qi)(qi)(qi)車(che)(che)(che)的(de)安全性能,因此,汽(qi)(qi)(qi)車(che)(che)(che)產(chan)(chan)量(liang)和單車(che)(che)(che)用(yong)(yong)量(liang)水(shui)平的(de)提(ti)高(gao)都將(jiang)推動(dong)汽(qi)(qi)(qi)車(che)(che)(che)工(gong)(gong)業對硅橡膠需求的(de)增(zeng)加(jia)。國(guo)家鼓勵自主(zhu)品(pin)牌(pai)的(de)汽(qi)(qi)(qi)車(che)(che)(che)發展,關鍵汽(qi)(qi)(qi)車(che)(che)(che)零部件(jian)實現(xian)自主(zhu)化(hua),《2012年(nian)度(du)黨政機關公(gong)務用(yong)(yong)車(che)(che)(che)選用(yong)(yong)車(che)(che)(che)型目錄(征求意見稿)》為自主(zhu)品(pin)牌(pai)擴(kuo)大(da)在(zai)政府采(cai)購的(de)市場(chang)份額,為改(gai)變目前國(guo)內政府采(cai)購以(yi)合資品(pin)牌(pai)產(chan)(chan)品(pin)為主(zhu)的(de)局(ju)面提(ti)供了保(bao)障(zhang)。促進自主(zhu)品(pin)牌(pai)發展,國(guo)產(chan)(chan)汽(qi)(qi)(qi)車(che)(che)(che)業的(de)繁榮將(jiang)為汽(qi)(qi)(qi)車(che)(che)(che)膠的(de)應用(yong)(yong)提(ti)供有(you)力保(bao)障(zhang)。預測未來3年(nian),我國(guo)室溫硫(liu)化(hua)硅橡膠在(zai)汽(qi)(qi)(qi)車(che)(che)(che)行業將(jiang)以(yi)年(nian)均(jun)20%增(zeng)長(chang)(chang)。
此外,硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重要(yao)的(de)(de)非石(shi)油(you)基(ji)(ji)(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油(you)基(ji)(ji)(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消費(fei)量的(de)(de)98%。但因(yin)為(wei)石(shi)油(you)價(jia)格的(de)(de)大(da)(da)(da)幅上(shang)漲,同時我國(guo)(guo)在硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關(guan)鍵原料(liao)有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)單體的(de)(de)生(sheng)產(chan)技術方(fang)面(mian)取得突破,有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)單體的(de)(de)生(sheng)產(chan)技術在2005年前(qian)被幾家(jia)跨國(guo)(guo)公司壟斷,但目前(qian)我國(guo)(guo)已發展成(cheng)(cheng)(cheng)為(wei)全球(qiu)有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)單體第1大(da)(da)(da)國(guo)(guo),這(zhe)2個方(fang)面(mian)原因(yin)使硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價(jia)格從2011年起(qi)開始低于石(shi)油(you)基(ji)(ji)(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大(da)(da)(da)宗石(shi)油(you)基(ji)(ji)(ji)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉(lian)價(jia)的(de)(de)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并開始大(da)(da)(da)規模替代石(shi)油(you)基(ji)(ji)(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將(jiang)極(ji)大(da)(da)(da)拓展有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)業(ye)的(de)(de)市場空(kong)間(jian),同時將(jiang)帶動硅(gui)(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)(gui)烷偶(ou)聯劑和(he)硅(gui)(gui)(gui)(gui)樹脂等其他有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)品的(de)(de)消費(fei)。