
硅橡膠是(shi)指主鏈由硅(gui)和氧(yang)原子交替構成,硅(gui)原子上通(tong)常連有(you)(you)兩個(ge)有(you)(you)機基團的(de)(de)(de)(de)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠。普通(tong)的(de)(de)(de)(de)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠主要由含甲基和少量(liang)乙烯(xi)基的(de)(de)(de)(de)硅(gui)氧(yang)鏈節組成。苯基的(de)(de)(de)(de)引(yin)入(ru)可(ke)提(ti)高硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)耐(nai)(nai)(nai)(nai)高、低溫(wen)性(xing)能(neng),三氟丙基及氰基的(de)(de)(de)(de)引(yin)入(ru)則(ze)可(ke)提(ti)高硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)耐(nai)(nai)(nai)(nai)溫(wen)及耐(nai)(nai)(nai)(nai)油(you)性(xing)能(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠耐(nai)(nai)(nai)(nai)低溫(wen)性(xing)能(neng)良好(hao),一般在-55℃下仍能(neng)工作。引(yin)入(ru)苯基后,可(ke)達-73℃。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)耐(nai)(nai)(nai)(nai)熱性(xing)能(neng)也很突(tu)(tu)出,在180℃下可(ke)長期工作,稍高于200℃也能(neng)承受數周或更長時(shi)間仍有(you)(you)彈(dan)性(xing),瞬時(shi)可(ke)耐(nai)(nai)(nai)(nai)300℃以(yi)上的(de)(de)(de)(de)高溫(wen)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)(de)(de)(de)透(tou)氣性(xing)好(hao),氧(yang)氣透(tou)過率在合(he)成聚合(he)物中是(shi)較高的(de)(de)(de)(de)。此外,硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠還具有(you)(you)生理惰性(xing)、不會導(dao)致(zhi)凝血(xue)的(de)(de)(de)(de)突(tu)(tu)出特性(xing),因此在醫用領域應用廣(guang)泛。
主要品種
硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠分(fen)(fen)類的(de)方法很多,通(tong)常按固化(hua)前的(de)形態分(fen)(fen)為固體(ti)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠和液體(ti)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠;按硫化(hua)溫(wen)度分(fen)(fen)為室溫(wen)硫化(hua)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠,高(gao)溫(wen)硫化(hua)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠;按所(suo)用(yong)單體(ti)的(de)不同,可(ke)分(fen)(fen)為甲(jia)基(ji)(ji)(ji)乙烯基(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠,甲(jia)基(ji)(ji)(ji)苯基(ji)(ji)(ji)乙烯基(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠、氟(fu)硅(gui),腈硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠等(deng);按性能和用(yong)途(tu)的(de)不同又可(ke)分(fen)(fen)為通(tong)用(yong)型、超(chao)耐低溫(wen)型、超(chao)耐高(gao)溫(wen)型、高(gao)強力型、耐油型、醫用(yong)型等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)(gui)橡膠(jiao)早期(qi)是由(you)美(mei)(mei)國(guo)以三氯化鐵為(wei)催(cui)化劑合成的(de)。1945年(nian),硅(gui)(gui)(gui)(gui)橡膠(jiao)產(chan)(chan)品(pin)問世(shi)。1948年(nian),采用(yong)(yong)高(gao)比表面(mian)積(ji)的(de)氣相法白炭(tan)黑補強的(de)硅(gui)(gui)(gui)(gui)橡膠(jiao)研(yan)制(zhi)成功,使硅(gui)(gui)(gui)(gui)橡膠(jiao)的(de)性(xing)能躍升到實用(yong)(yong)階段(duan),奠定了現代硅(gui)(gui)(gui)(gui)橡膠(jiao)生(sheng)產(chan)(chan)技(ji)術的(de)基(ji)礎。從二甲基(ji)二氯硅(gui)(gui)(gui)(gui)烷(wan)合成開始生(sheng)產(chan)(chan)硅(gui)(gui)(gui)(gui)橡膠(jiao)的(de)國(guo)家(jia)有(you)美(mei)(mei)國(guo)。俄羅(luo)斯、德(de)國(guo)、日本(ben)、韓國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡膠(jiao)的(de)工業化研(yan)究始于1957年(nian),多家(jia)研(yan)究所和企業陸續開發(fa)出各種硅(gui)(gui)(gui)(gui)橡膠(jiao)。到2003年(nian)底,中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡膠(jiao)生(sheng)產(chan)(chan)能力(li)為(wei)135千噸,其中(zhong)高(gao)溫膠(jiao)100千噸。
高溫硫化硅橡膠
高溫(wen)硫化(hua)硅橡膠是指聚硅氧烷變(bian)成(cheng)(cheng)彈(dan)(dan)性體(ti)的過程是經過高溫(wen)(110-170℃)硫化(hua)成(cheng)(cheng)型(xing)的。它主要以高分子量(liang)的聚甲基乙烯基硅氧烷為生膠,混入補強(qiang)(qiang)(qiang)填料(liao)、硫化(hua)劑(ji)等,在(zai)加(jia)熱加(jia)壓(ya)下硫化(hua)成(cheng)(cheng)彈(dan)(dan)性體(ti)。硅橡膠的補強(qiang)(qiang)(qiang)主要是各種類型(xing)的白炭(tan)黑,可使硫化(hua)膠的強(qiang)(qiang)(qiang)度增加(jia)數十倍(bei)。有時為了(le)降低成(cheng)(cheng)本或改善膠料(liao)性能及賦予硫化(hua)膠各種特殊的性能,也加(jia)入相應(ying)的各種添加(jia)劑(ji)。硫化(hua)劑(ji)是各種有機過氧化(hua)物或加(jia)成(cheng)(cheng)反應(ying)催化(hua)劑(ji)。
加工(gong)成型(xing)方法如圖所示(shi)。一次硫(liu)(liu)化(hua)的目的是(shi)進(jin)行高分子鏈的交(jiao)聯反應;二次硫(liu)(liu)化(hua)的目的是(shi)進(jin)行補充交(jiao)聯、驅除硫(liu)(liu)化(hua)劑分解(jie)產(chan)物和其(qi)他(ta)揮發性(xing)化(hua)合物以穩(wen)定硫(liu)(liu)化(hua)膠(jiao)的各(ge)項性(xing)能(neng)。常用的設(she)備有開(kai)放式煉膠(jiao)機、捏合機及真空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)僅是(shi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半,但在200℃以上(shang)的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環(huan)境下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)保(bao)持(chi)一定的(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)表面硬度(du),且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)無(wu)(wu)明(ming)顯變化。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃化溫(wen)(wen)(wen)(wen)度(du)一般為-70~-50℃,特(te)殊配方可達-100℃,表明(ming)其(qi)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)異。這對航空(kong)、宇航工業的(de)(de)意義重大。(3)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭(chou)氧(yang)及紫外線等十分穩(wen)定,在不加任何添加劑的(de)(de)情況下(xia),就具(ju)有(you)(you)(you)優(you)(you)良的(de)(de)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)(you)(you)優(you)(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng),耐(nai)(nai)(nai)電暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)比(bi)通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)低(di)溫(wen)(wen)(wen)(wen)下(xia),其(qi)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)(you)(you)中等的(de)(de)耐(nai)(nai)(nai)油、耐(nai)(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空(kong)氣(qi)、氮、氧(yang)、二氧(yang)化碳等氣(qi)體的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(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)有(you)(you)(you)抗凝血作(zuo)用,對肌體組織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少(shao)。特(te)別(bie)適合作(zuo)為醫用材料。
硅橡膠的用量
據(ju)中國(guo)(guo)汽(qi)車(che)(che)(che)(che)工業協會統(tong)計,2012年,汽(qi)車(che)(che)(che)(che)產(chan)銷分(fen)別(bie)達到1927.18萬輛(liang)(liang)和(he)1930.64萬輛(liang)(liang),同比(bi)分(fen)別(bie)增長(chang)4.63%和(he)4.33%,汽(qi)車(che)(che)(che)(che)工業硅橡(xiang)(xiang)膠的用(yong)量(liang)約達2.0萬t。根(gen)據(ju)觀(guan)研天(tian)下的新研究,增加有機(ji)硅材料在(zai)(zai)汽(qi)車(che)(che)(che)(che)零部件方面(mian)的用(yong)量(liang),可以大(da)幅度提高(gao)汽(qi)車(che)(che)(che)(che)的安全性能,因此,汽(qi)車(che)(che)(che)(che)產(chan)量(liang)和(he)單車(che)(che)(che)(che)用(yong)量(liang)水平的提高(gao)都(dou)將(jiang)(jiang)推(tui)動(dong)汽(qi)車(che)(che)(che)(che)工業對硅橡(xiang)(xiang)膠需(xu)求(qiu)的增加。國(guo)(guo)家鼓勵自(zi)主(zhu)(zhu)品(pin)牌(pai)(pai)的汽(qi)車(che)(che)(che)(che)發(fa)展,關鍵汽(qi)車(che)(che)(che)(che)零部件實(shi)現自(zi)主(zhu)(zhu)化(hua)(hua),《2012年度黨政機(ji)關公務用(yong)車(che)(che)(che)(che)選(xuan)用(yong)車(che)(che)(che)(che)型目(mu)(mu)錄(征求(qiu)意見稿)》為自(zi)主(zhu)(zhu)品(pin)牌(pai)(pai)擴大(da)在(zai)(zai)政府采購的市場(chang)份(fen)額(e),為改變目(mu)(mu)前(qian)國(guo)(guo)內政府采購以合(he)資品(pin)牌(pai)(pai)產(chan)品(pin)為主(zhu)(zhu)的局面(mian)提供了保障(zhang)。促進自(zi)主(zhu)(zhu)品(pin)牌(pai)(pai)發(fa)展,國(guo)(guo)產(chan)汽(qi)車(che)(che)(che)(che)業的繁(fan)榮將(jiang)(jiang)為汽(qi)車(che)(che)(che)(che)膠的應(ying)用(yong)提供有力(li)保障(zhang)。預測未來3年,我國(guo)(guo)室溫(wen)硫化(hua)(hua)硅橡(xiang)(xiang)膠在(zai)(zai)汽(qi)車(che)(che)(che)(che)行業將(jiang)(jiang)以年均20%增長(chang)。
此外,硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)是重(zhong)要的非石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消費量的98%。但(dan)因為石(shi)(shi)(shi)油價(jia)(jia)格(ge)的大(da)幅(fu)上(shang)漲,同(tong)時(shi)我(wo)國(guo)(guo)在硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的關鍵(jian)原料有機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)單(dan)體的生產(chan)(chan)技(ji)術方面取得突破,有機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)單(dan)體的生產(chan)(chan)技(ji)術在2005年前被幾(ji)家跨(kua)國(guo)(guo)公(gong)司(si)壟斷(duan),但(dan)目前我(wo)國(guo)(guo)已(yi)發展(zhan)成(cheng)(cheng)為全球有機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)單(dan)體第1大(da)國(guo)(guo),這2個方面原因使硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的價(jia)(jia)格(ge)從2011年起(qi)開始(shi)低于石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅(jin)約為大(da)宗(zong)石(shi)(shi)(shi)油基(ji)(ji)橡(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)(cheng)為廉價(jia)(jia)的合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開始(shi)大(da)規(gui)模替代石(shi)(shi)(shi)油基(ji)(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)拓展(zhan)有機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)產(chan)(chan)業(ye)的市(shi)場空間,同(tong)時(shi)將(jiang)帶動硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)油、硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)烷(wan)偶聯劑(ji)和硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)樹脂(zhi)等其他有機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)(gui)(gui)產(chan)(chan)品的消費。