
硅橡膠是指主(zhu)鏈由硅(gui)(gui)和氧(yang)原子(zi)交替(ti)構(gou)成(cheng),硅(gui)(gui)原子(zi)上通常連有(you)兩(liang)個有(you)機基(ji)(ji)團的橡(xiang)膠。普通的硅(gui)(gui)橡(xiang)膠主(zhu)要由含甲基(ji)(ji)和少量乙烯基(ji)(ji)的硅(gui)(gui)氧(yang)鏈節(jie)組成(cheng)。苯(ben)基(ji)(ji)的引入可(ke)提高(gao)(gao)硅(gui)(gui)橡(xiang)膠的耐(nai)(nai)(nai)高(gao)(gao)、低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng),三氟丙基(ji)(ji)及(ji)氰基(ji)(ji)的引入則可(ke)提高(gao)(gao)硅(gui)(gui)橡(xiang)膠的耐(nai)(nai)(nai)溫(wen)及(ji)耐(nai)(nai)(nai)油性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)膠耐(nai)(nai)(nai)低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng)良好(hao),一般在(zai)-55℃下(xia)(xia)仍(reng)能(neng)(neng)(neng)工作。引入苯(ben)基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)橡(xiang)膠的耐(nai)(nai)(nai)熱(re)性(xing)(xing)能(neng)(neng)(neng)也很突出,在(zai)180℃下(xia)(xia)可(ke)長期工作,稍高(gao)(gao)于200℃也能(neng)(neng)(neng)承受數周或(huo)更(geng)長時間仍(reng)有(you)彈性(xing)(xing),瞬(shun)時可(ke)耐(nai)(nai)(nai)300℃以(yi)上的高(gao)(gao)溫(wen)。硅(gui)(gui)橡(xiang)膠的透(tou)氣(qi)性(xing)(xing)好(hao),氧(yang)氣(qi)透(tou)過率(lv)在(zai)合(he)成(cheng)聚(ju)合(he)物中是較高(gao)(gao)的。此外,硅(gui)(gui)橡(xiang)膠還具有(you)生理惰(duo)性(xing)(xing)、不會導致凝血(xue)的突出特性(xing)(xing),因此在(zai)醫(yi)用領域應用廣(guang)泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠分(fen)(fen)類的方法很多,通(tong)常按(an)固化前(qian)的形態分(fen)(fen)為(wei)固體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠和(he)液體硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠;按(an)硫(liu)化溫(wen)度(du)分(fen)(fen)為(wei)室溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠,高(gao)(gao)溫(wen)硫(liu)化硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠;按(an)所(suo)用單體的不(bu)同(tong)(tong),可(ke)分(fen)(fen)為(wei)甲基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠,甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠、氟(fu)硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠等;按(an)性(xing)能(neng)和(he)用途(tu)的不(bu)同(tong)(tong)又(you)可(ke)分(fen)(fen)為(wei)通(tong)用型、超耐(nai)低溫(wen)型、超耐(nai)高(gao)(gao)溫(wen)型、高(gao)(gao)強力型、耐(nai)油型、醫用型等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由(you)美國(guo)(guo)(guo)以三氯(lv)化鐵為催化劑合成(cheng)(cheng)的(de)。1945年,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世。1948年,采用(yong)高比表(biao)面(mian)積的(de)氣相法白炭(tan)黑(hei)補(bu)強的(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)性能躍升到(dao)實用(yong)階段,奠定了現代硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)技術的(de)基礎。從二(er)甲基二(er)氯(lv)硅(gui)(gui)(gui)烷合成(cheng)(cheng)開始生(sheng)(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)(guo)(guo)家(jia)有美國(guo)(guo)(guo)。俄羅斯(si)、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和(he)中(zhong)國(guo)(guo)(guo)等。中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)工業化研(yan)究(jiu)始于1957年,多家(jia)研(yan)究(jiu)所和(he)企業陸續開發出各種(zhong)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年底(di),中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產(chan)能力(li)為135千噸,其中(zhong)高溫(wen)膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)(gao)溫硫化(hua)(hua)硅橡膠是指聚(ju)硅氧(yang)烷變成(cheng)彈性體(ti)的(de)(de)過(guo)程(cheng)是經過(guo)高(gao)(gao)溫(110-170℃)硫化(hua)(hua)成(cheng)型的(de)(de)。它主要(yao)以高(gao)(gao)分(fen)子量的(de)(de)聚(ju)甲基(ji)乙烯基(ji)硅氧(yang)烷為生膠,混入補強填料、硫化(hua)(hua)劑(ji)等,在加(jia)熱加(jia)壓下硫化(hua)(hua)成(cheng)彈性體(ti)。硅橡膠的(de)(de)補強主要(yao)是各(ge)(ge)種(zhong)(zhong)(zhong)類型的(de)(de)白炭黑,可使(shi)硫化(hua)(hua)膠的(de)(de)強度(du)增加(jia)數(shu)十倍。有(you)時為了(le)降低成(cheng)本或改善(shan)膠料性能及賦予(yu)硫化(hua)(hua)膠各(ge)(ge)種(zhong)(zhong)(zhong)特殊的(de)(de)性能,也加(jia)入相應的(de)(de)各(ge)(ge)種(zhong)(zhong)(zhong)添加(jia)劑(ji)。硫化(hua)(hua)劑(ji)是各(ge)(ge)種(zhong)(zhong)(zhong)有(you)機過(guo)氧(yang)化(hua)(hua)物或加(jia)成(cheng)反應催(cui)化(hua)(hua)劑(ji)。
加(jia)工成(cheng)型方法如圖所示。一(yi)次(ci)硫(liu)化(hua)(hua)(hua)的(de)目(mu)的(de)是進行(xing)高分子鏈的(de)交(jiao)聯(lian)反(fan)應;二次(ci)硫(liu)化(hua)(hua)(hua)的(de)目(mu)的(de)是進行(xing)補充交(jiao)聯(lian)、驅除(chu)硫(liu)化(hua)(hua)(hua)劑分解產物(wu)和其(qi)他揮發性化(hua)(hua)(hua)合物(wu)以穩定硫(liu)化(hua)(hua)(hua)膠的(de)各項性能。常用的(de)設(she)備有開放式煉膠機、捏合機及真(zhen)空(kong)密煉機。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的(de)(de)特(te)征是高(gao)溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)溫(wen)(wen)下(xia)(xia)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)強(qiang)度(du)(du)僅是天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)一半,但在(zai)200℃以(yi)上(shang)的(de)(de)高(gao)溫(wen)(wen)環境(jing)下(xia)(xia),硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)(neng)保持一定(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和(he)表面硬(ying)度(du)(du),且力學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)明顯(xian)變(bian)化(hua)(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)玻(bo)璃化(hua)(hua)溫(wen)(wen)度(du)(du)一般為-70~-50℃,特(te)殊(shu)配方可達-100℃,表明其(qi)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)異。這對(dui)(dui)航(hang)空、宇航(hang)工業的(de)(de)意(yi)義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧、臭氧及紫外線等(deng)十分(fen)穩定(ding),在(zai)不加任(ren)何添加劑的(de)(de)情況下(xia)(xia),就具有(you)優(you)良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具有(you)優(you)異的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下(xia)(xia)的(de)(de)物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)150℃的(de)(de)高(gao)溫(wen)(wen)和(he)-50℃的(de)(de)低溫(wen)(wen)下(xia)(xia),其(qi)物(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)油及化(hua)(hua)學試劑性(xing)(xing)(xing)(xing)(xing)。普通(tong)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具有(you)中等(deng)的(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣、氮、氧、二氧化(hua)(hua)碳等(deng)氣體的(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅,與人體組織(zhi)不粘連(lian),具有(you)抗凝血作用(yong),對(dui)(dui)肌體組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特(te)別(bie)適合作為醫用(yong)材料。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)協會統(tong)計(ji),2012年(nian),汽(qi)(qi)(qi)車(che)(che)產(chan)銷分別(bie)達(da)到(dao)1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同(tong)比分別(bie)增長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)硅(gui)橡(xiang)(xiang)膠的(de)用(yong)量約(yue)達(da)2.0萬(wan)t。根據(ju)觀(guan)研天下的(de)新研究(jiu),增加有(you)(you)機(ji)硅(gui)材料在汽(qi)(qi)(qi)車(che)(che)零部件方面(mian)的(de)用(yong)量,可(ke)以(yi)大(da)幅度提高汽(qi)(qi)(qi)車(che)(che)的(de)安(an)全性能(neng),因此,汽(qi)(qi)(qi)車(che)(che)產(chan)量和(he)單(dan)車(che)(che)用(yong)量水平的(de)提高都將(jiang)推動汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)對(dui)硅(gui)橡(xiang)(xiang)膠需求的(de)增加。國(guo)家鼓勵自主品(pin)牌(pai)(pai)(pai)的(de)汽(qi)(qi)(qi)車(che)(che)發展(zhan),關(guan)(guan)鍵汽(qi)(qi)(qi)車(che)(che)零部件實現自主化,《2012年(nian)度黨政機(ji)關(guan)(guan)公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(征求意見稿)》為(wei)(wei)自主品(pin)牌(pai)(pai)(pai)擴大(da)在政府采(cai)購的(de)市場份額(e),為(wei)(wei)改變目前國(guo)內(nei)政府采(cai)購以(yi)合資品(pin)牌(pai)(pai)(pai)產(chan)品(pin)為(wei)(wei)主的(de)局面(mian)提供了保(bao)障。促進(jin)自主品(pin)牌(pai)(pai)(pai)發展(zhan),國(guo)產(chan)汽(qi)(qi)(qi)車(che)(che)業(ye)的(de)繁(fan)榮將(jiang)為(wei)(wei)汽(qi)(qi)(qi)車(che)(che)膠的(de)應用(yong)提供有(you)(you)力保(bao)障。預測未來3年(nian),我國(guo)室溫硫化硅(gui)橡(xiang)(xiang)膠在汽(qi)(qi)(qi)車(che)(che)行業(ye)將(jiang)以(yi)年(nian)均(jun)20%增長。
此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)是重(zhong)要的(de)(de)非(fei)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合成橡(xiang)(xiang)(xiang)膠(jiao),約占非(fei)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合成橡(xiang)(xiang)(xiang)膠(jiao)消費量的(de)(de)98%。但(dan)因為(wei)(wei)石(shi)(shi)油(you)(you)(you)價格(ge)的(de)(de)大(da)(da)(da)幅上漲,同時(shi)我國(guo)(guo)在硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)關鍵(jian)原料有(you)(you)機(ji)(ji)硅(gui)(gui)單(dan)體的(de)(de)生產(chan)技術方(fang)面取得突破,有(you)(you)機(ji)(ji)硅(gui)(gui)單(dan)體的(de)(de)生產(chan)技術在2005年前被(bei)幾家跨國(guo)(guo)公司壟斷,但(dan)目前我國(guo)(guo)已發展成為(wei)(wei)全球有(you)(you)機(ji)(ji)硅(gui)(gui)單(dan)體第1大(da)(da)(da)國(guo)(guo),這2個(ge)方(fang)面原因使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)價格(ge)從2011年起開(kai)始(shi)低(di)于石(shi)(shi)油(you)(you)(you)基(ji)(ji)合成橡(xiang)(xiang)(xiang)膠(jiao),僅約為(wei)(wei)大(da)(da)(da)宗石(shi)(shi)油(you)(you)(you)基(ji)(ji)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)80%~90%,成為(wei)(wei)廉價的(de)(de)合成橡(xiang)(xiang)(xiang)膠(jiao),并開(kai)始(shi)大(da)(da)(da)規模替代石(shi)(shi)油(you)(you)(you)基(ji)(ji)合成橡(xiang)(xiang)(xiang)膠(jiao)。這將(jiang)極大(da)(da)(da)拓展有(you)(you)機(ji)(ji)硅(gui)(gui)產(chan)業的(de)(de)市(shi)場(chang)空間(jian),同時(shi)將(jiang)帶動硅(gui)(gui)油(you)(you)(you)、硅(gui)(gui)烷偶聯劑(ji)和(he)硅(gui)(gui)樹脂等其他有(you)(you)機(ji)(ji)硅(gui)(gui)產(chan)品的(de)(de)消費。