
硅橡膠是指主鏈由硅(gui)(gui)和氧原(yuan)子(zi)交替構成(cheng),硅(gui)(gui)原(yuan)子(zi)上(shang)通(tong)常連(lian)有兩個有機(ji)基(ji)(ji)團的(de)(de)橡(xiang)(xiang)膠。普通(tong)的(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠主要由含甲基(ji)(ji)和少量乙(yi)烯(xi)基(ji)(ji)的(de)(de)硅(gui)(gui)氧鏈節組成(cheng)。苯(ben)基(ji)(ji)的(de)(de)引(yin)入可(ke)(ke)(ke)(ke)提(ti)高(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)高(gao)、低溫性(xing)(xing)能(neng)(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引(yin)入則(ze)可(ke)(ke)(ke)(ke)提(ti)高(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)溫及耐(nai)油性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠耐(nai)低溫性(xing)(xing)能(neng)(neng)(neng)良好,一般在(zai)-55℃下(xia)仍能(neng)(neng)(neng)工作。引(yin)入苯(ben)基(ji)(ji)后,可(ke)(ke)(ke)(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)熱性(xing)(xing)能(neng)(neng)(neng)也(ye)很突出(chu),在(zai)180℃下(xia)可(ke)(ke)(ke)(ke)長(chang)期工作,稍高(gao)于200℃也(ye)能(neng)(neng)(neng)承受(shou)數周或(huo)更長(chang)時(shi)間仍有彈性(xing)(xing),瞬(shun)時(shi)可(ke)(ke)(ke)(ke)耐(nai)300℃以(yi)上(shang)的(de)(de)高(gao)溫。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)透氣性(xing)(xing)好,氧氣透過率在(zai)合成(cheng)聚合物中是較高(gao)的(de)(de)。此外(wai),硅(gui)(gui)橡(xiang)(xiang)膠還具有生理惰性(xing)(xing)、不會導致凝血的(de)(de)突出(chu)特性(xing)(xing),因(yin)此在(zai)醫用(yong)領域應用(yong)廣(guang)泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)分(fen)(fen)類的(de)(de)方法很多,通常按(an)固化(hua)(hua)(hua)前的(de)(de)形態分(fen)(fen)為(wei)固體(ti)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)和(he)(he)液體(ti)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)硫(liu)化(hua)(hua)(hua)溫度分(fen)(fen)為(wei)室(shi)溫硫(liu)化(hua)(hua)(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao),高(gao)(gao)溫硫(liu)化(hua)(hua)(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)所用(yong)(yong)單體(ti)的(de)(de)不同(tong),可分(fen)(fen)為(wei)甲基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)等(deng);按(an)性能和(he)(he)用(yong)(yong)途的(de)(de)不同(tong)又可分(fen)(fen)為(wei)通用(yong)(yong)型(xing)(xing)、超耐低溫型(xing)(xing)、超耐高(gao)(gao)溫型(xing)(xing)、高(gao)(gao)強力型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)早(zao)期是(shi)由(you)美(mei)國(guo)以三氯化(hua)鐵(tie)為催化(hua)劑(ji)合(he)成的。1945年(nian),硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)產(chan)品問(wen)世。1948年(nian),采用高比表面積(ji)的氣相法白炭黑補強(qiang)的硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)研(yan)制成功,使硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性能(neng)躍升到實(shi)用階段,奠定了現(xian)代硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)技術(shu)的基礎。從二甲基二氯硅(gui)烷合(he)成開始生(sheng)產(chan)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國(guo)家有美(mei)國(guo)。俄羅(luo)斯、德(de)國(guo)、日(ri)本(ben)、韓(han)國(guo)和(he)中(zhong)國(guo)等(deng)。中(zhong)國(guo)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業化(hua)研(yan)究(jiu)始于1957年(nian),多(duo)家研(yan)究(jiu)所(suo)和(he)企業陸(lu)續開發出各種硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年(nian)底(di),中(zhong)國(guo)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)能(neng)力為135千噸(dun),其(qi)中(zhong)高溫膠(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)(liu)化硅橡膠(jiao)是(shi)(shi)指(zhi)聚(ju)(ju)硅氧(yang)烷(wan)變(bian)成(cheng)彈(dan)性體的(de)(de)(de)(de)過程是(shi)(shi)經(jing)過高溫(110-170℃)硫(liu)(liu)化成(cheng)型的(de)(de)(de)(de)。它主(zhu)要以高分(fen)子量的(de)(de)(de)(de)聚(ju)(ju)甲基乙烯基硅氧(yang)烷(wan)為生膠(jiao),混(hun)入(ru)補強(qiang)(qiang)填(tian)料、硫(liu)(liu)化劑等(deng),在加熱(re)加壓下硫(liu)(liu)化成(cheng)彈(dan)性體。硅橡膠(jiao)的(de)(de)(de)(de)補強(qiang)(qiang)主(zhu)要是(shi)(shi)各(ge)種(zhong)類型的(de)(de)(de)(de)白炭黑,可使硫(liu)(liu)化膠(jiao)的(de)(de)(de)(de)強(qiang)(qiang)度增(zeng)加數十倍(bei)。有(you)(you)時為了降低成(cheng)本或改善膠(jiao)料性能及賦(fu)予(yu)硫(liu)(liu)化膠(jiao)各(ge)種(zhong)特殊的(de)(de)(de)(de)性能,也加入(ru)相應的(de)(de)(de)(de)各(ge)種(zhong)添加劑。硫(liu)(liu)化劑是(shi)(shi)各(ge)種(zhong)有(you)(you)機過氧(yang)化物或加成(cheng)反應催化劑。
加工成型方法如圖所示。一(yi)次(ci)硫化的(de)(de)(de)目(mu)的(de)(de)(de)是進(jin)行(xing)高分子(zi)鏈的(de)(de)(de)交聯(lian)反應;二(er)次(ci)硫化的(de)(de)(de)目(mu)的(de)(de)(de)是進(jin)行(xing)補(bu)充交聯(lian)、驅除硫化劑分解產物和其他揮發性(xing)化合物以穩定(ding)硫化膠(jiao)的(de)(de)(de)各項性(xing)能。常(chang)用的(de)(de)(de)設備有開(kai)放式(shi)煉(lian)膠(jiao)機(ji)、捏合機(ji)及真(zhen)空密煉(lian)機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)(xian)著的(de)特征是(shi)高(gao)溫(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)強度(du)僅(jin)是(shi)天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些(xie)合(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)一半(ban),但在200℃以上的(de)高(gao)溫(wen)(wen)環境下,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一定(ding)(ding)的(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬(ying)度(du),且力(li)學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明(ming)顯(xian)(xian)變化(hua)(hua)(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)玻璃化(hua)(hua)(hua)溫(wen)(wen)度(du)一般為(wei)-70~-50℃,特殊(shu)配方可(ke)達(da)-100℃,表明(ming)其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優異(yi)(yi)。這對航空、宇航工(gong)業的(de)意義重大。(3)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及紫(zi)外線等(deng)(deng)十(shi)分穩定(ding)(ding),在不(bu)加任(ren)何添加劑(ji)的(de)情況下,就具(ju)有優良的(de)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有優異(yi)(yi)的(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)(nai)(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物理機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)(wen)下的(de)物理機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在150℃的(de)高(gao)溫(wen)(wen)和(he)(he)-50℃的(de)低溫(wen)(wen)下,其物理機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優于通(tong)(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)(nai)(nai)油及化(hua)(hua)(hua)學試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)。普通(tong)(tong)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有中等(deng)(deng)的(de)耐(nai)(nai)(nai)(nai)油、耐(nai)(nai)(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對空氣(qi)(qi)、氮(dan)、氧(yang)、二氧(yang)化(hua)(hua)(hua)碳等(deng)(deng)氣(qi)(qi)體(ti)(ti)的(de)透(tou)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒(du),無(wu)味,無(wu)嗅,與(yu)人(ren)體(ti)(ti)組織不(bu)粘連,具(ju)有抗凝血作(zuo)(zuo)用(yong)(yong),對肌(ji)體(ti)(ti)組織的(de)反應性(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別(bie)適合(he)作(zuo)(zuo)為(wei)醫用(yong)(yong)材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業(ye)(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產銷分別達到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同比分別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業(ye)(ye)硅(gui)橡膠(jiao)的(de)(de)用(yong)(yong)(yong)量約達2.0萬(wan)(wan)t。根據觀(guan)研(yan)天下的(de)(de)新研(yan)究,增(zeng)加有機硅(gui)材料在(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件(jian)(jian)方(fang)面的(de)(de)用(yong)(yong)(yong)量,可(ke)以(yi)大幅度(du)提(ti)(ti)高汽(qi)(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)安全性能,因此,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)產量和(he)單(dan)車(che)(che)用(yong)(yong)(yong)量水平的(de)(de)提(ti)(ti)高都將推動(dong)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)工(gong)業(ye)(ye)對硅(gui)橡膠(jiao)需求的(de)(de)增(zeng)加。國家(jia)鼓勵自(zi)主(zhu)品牌(pai)的(de)(de)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)發(fa)展,關鍵汽(qi)(qi)(qi)(qi)(qi)車(che)(che)零部(bu)件(jian)(jian)實現自(zi)主(zhu)化,《2012年(nian)(nian)度(du)黨政(zheng)機關公務(wu)用(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)車(che)(che)型目(mu)錄(征求意見(jian)稿)》為自(zi)主(zhu)品牌(pai)擴大在(zai)政(zheng)府采(cai)購的(de)(de)市場份額,為改(gai)變(bian)目(mu)前國內政(zheng)府采(cai)購以(yi)合資品牌(pai)產品為主(zhu)的(de)(de)局面提(ti)(ti)供(gong)了(le)保障(zhang)。促進自(zi)主(zhu)品牌(pai)發(fa)展,國產汽(qi)(qi)(qi)(qi)(qi)車(che)(che)業(ye)(ye)的(de)(de)繁榮將為汽(qi)(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)(de)應用(yong)(yong)(yong)提(ti)(ti)供(gong)有力保障(zhang)。預測未來3年(nian)(nian),我國室溫硫化硅(gui)橡膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)行業(ye)(ye)將以(yi)年(nian)(nian)均(jun)20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)是重要的(de)非(fei)石(shi)油(you)(you)基(ji)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),約(yue)占非(fei)石(shi)油(you)(you)基(ji)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)消(xiao)費量的(de)98%。但因(yin)為(wei)(wei)石(shi)油(you)(you)價(jia)(jia)格的(de)大(da)幅上漲,同時我(wo)(wo)國在硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)關鍵原(yuan)料有(you)(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)(ti)的(de)生產技術(shu)方面取得突破,有(you)(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)(ti)的(de)生產技術(shu)在2005年前被幾家跨國公(gong)司壟斷,但目(mu)前我(wo)(wo)國已發展成為(wei)(wei)全球有(you)(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)(ti)第1大(da)國,這2個(ge)方面原(yuan)因(yin)使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)價(jia)(jia)格從(cong)2011年起開始低于石(shi)油(you)(you)基(ji)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),僅約(yue)為(wei)(wei)大(da)宗石(shi)油(you)(you)基(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)80%~90%,成為(wei)(wei)廉價(jia)(jia)的(de)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),并開始大(da)規模替代石(shi)油(you)(you)基(ji)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。這將(jiang)極大(da)拓展有(you)(you)(you)機硅(gui)(gui)(gui)產業(ye)的(de)市場空間,同時將(jiang)帶動硅(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)(gui)樹(shu)脂等(deng)其他有(you)(you)(you)機硅(gui)(gui)(gui)產品的(de)消(xiao)費。