
硅橡膠是指主鏈(lian)由硅(gui)(gui)和氧(yang)原子(zi)交替構成(cheng),硅(gui)(gui)原子(zi)上通(tong)常連有兩(liang)個有機基(ji)團的(de)(de)(de)(de)橡(xiang)(xiang)膠。普通(tong)的(de)(de)(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠主要由含甲(jia)基(ji)和少量乙(yi)烯基(ji)的(de)(de)(de)(de)硅(gui)(gui)氧(yang)鏈(lian)節組成(cheng)。苯基(ji)的(de)(de)(de)(de)引(yin)入(ru)可提高(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)(de)耐高(gao)、低溫性(xing)(xing)能(neng),三氟(fu)丙基(ji)及(ji)氰基(ji)的(de)(de)(de)(de)引(yin)入(ru)則可提高(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)(de)耐溫及(ji)耐油性(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)膠耐低溫性(xing)(xing)能(neng)良好(hao)(hao),一般在(zai)-55℃下(xia)(xia)仍能(neng)工作(zuo)(zuo)。引(yin)入(ru)苯基(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)(de)耐熱(re)性(xing)(xing)能(neng)也(ye)很突出,在(zai)180℃下(xia)(xia)可長期工作(zuo)(zuo),稍(shao)高(gao)于200℃也(ye)能(neng)承受(shou)數周或更長時間仍有彈(dan)性(xing)(xing),瞬(shun)時可耐300℃以上的(de)(de)(de)(de)高(gao)溫。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)(de)透(tou)氣性(xing)(xing)好(hao)(hao),氧(yang)氣透(tou)過率在(zai)合成(cheng)聚合物(wu)中是較高(gao)的(de)(de)(de)(de)。此(ci)外,硅(gui)(gui)橡(xiang)(xiang)膠還具有生(sheng)理惰(duo)性(xing)(xing)、不會(hui)導(dao)致凝血的(de)(de)(de)(de)突出特性(xing)(xing),因此(ci)在(zai)醫用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類的(de)方(fang)法很(hen)多,通(tong)常按固化(hua)(hua)前的(de)形(xing)態分(fen)為固體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和液體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按硫化(hua)(hua)溫(wen)度分(fen)為室溫(wen)硫化(hua)(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫化(hua)(hua)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按所用(yong)(yong)單(dan)體的(de)不同,可(ke)分(fen)為甲基(ji)(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲基(ji)(ji)(ji)(ji)苯基(ji)(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng);按性能(neng)和用(yong)(yong)途(tu)的(de)不同又可(ke)分(fen)為通(tong)用(yong)(yong)型(xing)、超耐(nai)低溫(wen)型(xing)、超耐(nai)高(gao)溫(wen)型(xing)、高(gao)強力型(xing)、耐(nai)油型(xing)、醫用(yong)(yong)型(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期(qi)是由美國(guo)(guo)以三氯化鐵為(wei)催化劑合成的。1945年,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產品(pin)問(wen)世(shi)。1948年,采(cai)用高比表(biao)面積的氣(qi)相法白炭黑補(bu)強(qiang)的硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研制成功(gong),使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性(xing)能躍升到實用階段,奠定(ding)了現代(dai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產技(ji)術的基礎(chu)。從(cong)二甲基二氯硅(gui)(gui)(gui)烷合成開始生產硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國(guo)(guo)家有美國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等(deng)。中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業化研究(jiu)始于1957年,多家研究(jiu)所和企業陸(lu)續開發出各種硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年底,中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產能力為(wei)135千(qian)噸,其中(zhong)高溫(wen)膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫(wen)硫(liu)化(hua)(hua)硅橡膠(jiao)(jiao)是指(zhi)聚硅氧烷變成彈性體(ti)的過程是經過高溫(wen)(110-170℃)硫(liu)化(hua)(hua)成型(xing)的。它(ta)主(zhu)要(yao)以(yi)高分子量的聚甲基乙烯基硅氧烷為生(sheng)膠(jiao)(jiao),混入補強填料(liao)、硫(liu)化(hua)(hua)劑等,在加熱加壓下(xia)硫(liu)化(hua)(hua)成彈性體(ti)。硅橡膠(jiao)(jiao)的補強主(zhu)要(yao)是各(ge)(ge)種(zhong)(zhong)類型(xing)的白炭黑,可使硫(liu)化(hua)(hua)膠(jiao)(jiao)的強度增加數十倍。有時為了降低成本或改善膠(jiao)(jiao)料(liao)性能及賦予硫(liu)化(hua)(hua)膠(jiao)(jiao)各(ge)(ge)種(zhong)(zhong)特殊的性能,也(ye)加入相(xiang)應的各(ge)(ge)種(zhong)(zhong)添(tian)加劑。硫(liu)化(hua)(hua)劑是各(ge)(ge)種(zhong)(zhong)有機過氧化(hua)(hua)物或加成反應催化(hua)(hua)劑。
加工(gong)成型方法如圖所示(shi)。一次(ci)硫(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是(shi)進(jin)行(xing)高分(fen)子鏈的(de)(de)交聯反應;二次(ci)硫(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是(shi)進(jin)行(xing)補(bu)充交聯、驅除硫(liu)化(hua)(hua)劑分(fen)解產物和其他揮發(fa)性化(hua)(hua)合物以穩定(ding)硫(liu)化(hua)(hua)膠的(de)(de)各項性能。常用(yong)的(de)(de)設備有(you)開放式煉膠機(ji)(ji)、捏合機(ji)(ji)及真空密(mi)煉機(ji)(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特征是(shi)高(gao)溫(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)(du)僅是(shi)天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但(dan)在(zai)200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持(chi)一(yi)定(ding)的(de)(de)(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du)(du),且力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度(du)(du)一(yi)般為-70~-50℃,特殊配方可達-100℃,表明其低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這(zhe)對(dui)(dui)航空(kong)、宇航工業(ye)的(de)(de)(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧(yang)、臭氧(yang)及紫外線等(deng)十分穩定(ding),在(zai)不加(jia)任何添(tian)加(jia)劑的(de)(de)(de)(de)(de)情況下,就具(ju)有優(you)良的(de)(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有優(you)異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好(hao)。(5)物理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)(wen)下的(de)(de)(de)(de)(de)物理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)下,其物理(li)(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有中等(deng)的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)(dui)空(kong)氣(qi)(qi)、氮、氧(yang)、二(er)氧(yang)化碳等(deng)氣(qi)(qi)體(ti)的(de)(de)(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍(bei)。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與人體(ti)組(zu)織(zhi)不粘連,具(ju)有抗凝血(xue)作用(yong),對(dui)(dui)肌體(ti)組(zu)織(zhi)的(de)(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特別適合作為醫用(yong)材料。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業協會統計,2012年(nian),汽(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)銷分(fen)別達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比分(fen)別增長(chang)4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業硅(gui)橡膠(jiao)的(de)(de)用(yong)量約(yue)達2.0萬(wan)t。根據(ju)觀研天下的(de)(de)新(xin)研究,增加(jia)有機硅(gui)材料在(zai)汽(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)方面(mian)的(de)(de)用(yong)量,可(ke)以大幅度(du)提(ti)高(gao)汽(qi)(qi)(qi)(qi)車(che)(che)(che)的(de)(de)安全(quan)性(xing)能(neng),因此,汽(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)量和單車(che)(che)(che)用(yong)量水平(ping)的(de)(de)提(ti)高(gao)都(dou)將(jiang)推動汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業對硅(gui)橡膠(jiao)需求(qiu)的(de)(de)增加(jia)。國(guo)家鼓勵自(zi)主(zhu)品牌(pai)的(de)(de)汽(qi)(qi)(qi)(qi)車(che)(che)(che)發(fa)(fa)展,關(guan)鍵(jian)汽(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)實現自(zi)主(zhu)化(hua),《2012年(nian)度(du)黨(dang)政(zheng)機關(guan)公務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目錄(征求(qiu)意(yi)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,為改變目前國(guo)內政(zheng)府采(cai)購以合資品牌(pai)產(chan)品為主(zhu)的(de)(de)局面(mian)提(ti)供了保障。促進自(zi)主(zhu)品牌(pai)發(fa)(fa)展,國(guo)產(chan)汽(qi)(qi)(qi)(qi)車(che)(che)(che)業的(de)(de)繁榮將(jiang)為汽(qi)(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的(de)(de)應用(yong)提(ti)供有力(li)保障。預測未來(lai)3年(nian),我國(guo)室(shi)溫硫化(hua)硅(gui)橡膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)車(che)(che)(che)行業將(jiang)以年(nian)均20%增長(chang)。
此外,硅(gui)橡(xiang)膠(jiao)是(shi)重要的(de)非(fei)石(shi)(shi)油(you)(you)基(ji)(ji)合成橡(xiang)膠(jiao),約占非(fei)石(shi)(shi)油(you)(you)基(ji)(ji)合成橡(xiang)膠(jiao)消費量(liang)的(de)98%。但(dan)因(yin)為石(shi)(shi)油(you)(you)價格的(de)大(da)幅上漲,同(tong)時我國(guo)(guo)在硅(gui)橡(xiang)膠(jiao)的(de)關鍵原料有(you)(you)機(ji)硅(gui)單體的(de)生(sheng)產(chan)技術方面取得(de)突破,有(you)(you)機(ji)硅(gui)單體的(de)生(sheng)產(chan)技術在2005年前被幾家(jia)跨(kua)國(guo)(guo)公司壟(long)斷,但(dan)目前我國(guo)(guo)已發展成為全球有(you)(you)機(ji)硅(gui)單體第1大(da)國(guo)(guo),這2個(ge)方面原因(yin)使硅(gui)橡(xiang)膠(jiao)的(de)價格從2011年起開(kai)始(shi)低于石(shi)(shi)油(you)(you)基(ji)(ji)合成橡(xiang)膠(jiao),僅約為大(da)宗石(shi)(shi)油(you)(you)基(ji)(ji)橡(xiang)膠(jiao)的(de)80%~90%,成為廉價的(de)合成橡(xiang)膠(jiao),并開(kai)始(shi)大(da)規(gui)模替代石(shi)(shi)油(you)(you)基(ji)(ji)合成橡(xiang)膠(jiao)。這將極大(da)拓展有(you)(you)機(ji)硅(gui)產(chan)業的(de)市(shi)場空(kong)間,同(tong)時將帶(dai)動硅(gui)油(you)(you)、硅(gui)烷偶聯劑和硅(gui)樹(shu)脂等其他有(you)(you)機(ji)硅(gui)產(chan)品的(de)消費。