硅橡膠是(shi)指主鏈由硅(gui)(gui)(gui)(gui)和氧(yang)原(yuan)子交(jiao)替構成,硅(gui)(gui)(gui)(gui)原(yuan)子上通(tong)常連有(you)兩個有(you)機基(ji)團的(de)(de)橡(xiang)(xiang)(xiang)(xiang)膠。普通(tong)的(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠主要(yao)由含甲(jia)基(ji)和少量乙烯基(ji)的(de)(de)硅(gui)(gui)(gui)(gui)氧(yang)鏈節組成。苯(ben)基(ji)的(de)(de)引(yin)入可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)(de)耐高(gao)、低(di)溫(wen)性能(neng),三氟丙基(ji)及(ji)(ji)氰基(ji)的(de)(de)引(yin)入則可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)(de)耐溫(wen)及(ji)(ji)耐油性能(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠耐低(di)溫(wen)性能(neng)良(liang)好,一般在-55℃下仍能(neng)工作。引(yin)入苯(ben)基(ji)后,可達(da)-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)(de)耐熱性能(neng)也很突出(chu),在180℃下可長(chang)(chang)期工作,稍高(gao)于200℃也能(neng)承受數周或更長(chang)(chang)時間仍有(you)彈(dan)性,瞬時可耐300℃以上的(de)(de)高(gao)溫(wen)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)(de)透氣性好,氧(yang)氣透過(guo)率(lv)在合(he)成聚合(he)物中是(shi)較高(gao)的(de)(de)。此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠還具有(you)生理惰(duo)性、不(bu)會導致凝血的(de)(de)突出(chu)特性,因(yin)此在醫用領域應(ying)用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)分(fen)類的方法很多,通(tong)常(chang)按固化(hua)前(qian)的形態(tai)分(fen)為(wei)固體(ti)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)和液體(ti)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按硫化(hua)溫度(du)分(fen)為(wei)室溫硫化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),高溫硫化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao);按所用單體(ti)的不同,可(ke)分(fen)為(wei)甲基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)等(deng);按性能和用途的不同又(you)可(ke)分(fen)為(wei)通(tong)用型(xing)(xing)(xing)、超耐低溫型(xing)(xing)(xing)、超耐高溫型(xing)(xing)(xing)、高強力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用型(xing)(xing)(xing)等(deng)等(deng)。
發展史
硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)早期是由美國(guo)(guo)以三氯化鐵為催化劑(ji)合成(cheng)的(de)。1945年(nian)(nian)(nian),硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)產品問世。1948年(nian)(nian)(nian),采用(yong)高比表(biao)面積(ji)的(de)氣(qi)相法白炭黑(hei)補強的(de)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)研制成(cheng)功(gong),使硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)性能躍升到(dao)實用(yong)階段,奠定了現代硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生產技術的(de)基(ji)礎。從二(er)甲(jia)基(ji)二(er)氯硅烷合成(cheng)開(kai)始生產硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)(guo)家有美國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中國(guo)(guo)等。中國(guo)(guo)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)(ye)化研究始于1957年(nian)(nian)(nian),多家研究所和企業(ye)(ye)陸續開(kai)發(fa)出各種硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)(nian)(nian)底,中國(guo)(guo)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生產能力為135千噸,其中高溫膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫化(hua)(hua)硅橡膠是(shi)指聚硅氧烷變成(cheng)(cheng)彈性體(ti)的過程是(shi)經過高(gao)溫(wen)(110-170℃)硫化(hua)(hua)成(cheng)(cheng)型的。它(ta)主要以(yi)高(gao)分子量的聚甲基乙烯基硅氧烷為生膠,混入(ru)補(bu)強(qiang)填料、硫化(hua)(hua)劑(ji)(ji)等,在加(jia)熱加(jia)壓下硫化(hua)(hua)成(cheng)(cheng)彈性體(ti)。硅橡膠的補(bu)強(qiang)主要是(shi)各(ge)(ge)種(zhong)類型的白炭黑,可使硫化(hua)(hua)膠的強(qiang)度增加(jia)數十倍。有時為了降低成(cheng)(cheng)本或改善膠料性能及賦(fu)予硫化(hua)(hua)膠各(ge)(ge)種(zhong)特殊的性能,也加(jia)入(ru)相應(ying)的各(ge)(ge)種(zhong)添加(jia)劑(ji)(ji)。硫化(hua)(hua)劑(ji)(ji)是(shi)各(ge)(ge)種(zhong)有機過氧化(hua)(hua)物或加(jia)成(cheng)(cheng)反應(ying)催化(hua)(hua)劑(ji)(ji)。
加工(gong)成型方(fang)法如圖所示。一次(ci)硫化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是進行高分子鏈的(de)(de)(de)交聯反應;二次(ci)硫化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是進行補充交聯、驅除硫化(hua)(hua)劑分解產物和其他(ta)揮發性(xing)化(hua)(hua)合(he)物以穩定硫化(hua)(hua)膠(jiao)的(de)(de)(de)各項(xiang)性(xing)能。常(chang)用的(de)(de)(de)設(she)備有開放(fang)式煉(lian)膠(jiao)機、捏合(he)機及真空密煉(lian)機。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)特(te)征是高(gao)(gao)溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)強度(du)僅是天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或(huo)某些合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)一(yi)(yi)半,但在(zai)200℃以上的(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)環境下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)保持(chi)一(yi)(yi)定的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)無(wu)明顯變化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度(du)一(yi)(yi)般為-70~-50℃,特(te)殊配方可達-100℃,表明其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)(you)異。這對(dui)航空、宇(yu)航工業的(de)(de)(de)意義重大。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)氧、臭氧及紫外線等(deng)十分穩定,在(zai)不(bu)(bu)加任(ren)何添加劑的(de)(de)(de)情況下(xia),就具(ju)(ju)有優(you)(you)(you)良的(de)(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有優(you)(you)(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)的(de)(de)(de)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)比(bi)(bi)通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)150℃的(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)和(he)(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下(xia),其物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)(you)(you)于通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)油及化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有中等(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。(7)氣體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。室溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)空氣、氮、氧、二氧化(hua)碳等(deng)氣體(ti)(ti)的(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)(bi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅,與人體(ti)(ti)組(zu)織不(bu)(bu)粘連,具(ju)(ju)有抗凝血作(zuo)(zuo)用(yong)(yong),對(dui)肌體(ti)(ti)組(zu)織的(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少(shao)。特(te)別適合作(zuo)(zuo)為醫用(yong)(yong)材料。
硅橡膠的用量
據中(zhong)國(guo)汽(qi)(qi)(qi)車(che)工(gong)業(ye)協會統計,2012年,汽(qi)(qi)(qi)車(che)產銷分別達到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同比分別增(zeng)(zeng)長(chang)(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)工(gong)業(ye)硅橡(xiang)膠(jiao)的(de)(de)(de)用(yong)量約達2.0萬(wan)t。根(gen)據觀研天下的(de)(de)(de)新研究,增(zeng)(zeng)加(jia)有(you)機(ji)(ji)硅材料在汽(qi)(qi)(qi)車(che)零部件方面(mian)(mian)的(de)(de)(de)用(yong)量,可以(yi)大幅(fu)度(du)提(ti)高(gao)汽(qi)(qi)(qi)車(che)的(de)(de)(de)安全性能,因此(ci),汽(qi)(qi)(qi)車(che)產量和(he)單車(che)用(yong)量水平的(de)(de)(de)提(ti)高(gao)都將(jiang)推動(dong)汽(qi)(qi)(qi)車(che)工(gong)業(ye)對(dui)硅橡(xiang)膠(jiao)需求(qiu)的(de)(de)(de)增(zeng)(zeng)加(jia)。國(guo)家鼓勵自主(zhu)(zhu)品牌的(de)(de)(de)汽(qi)(qi)(qi)車(che)發(fa)展(zhan)(zhan),關鍵汽(qi)(qi)(qi)車(che)零部件實現自主(zhu)(zhu)化(hua),《2012年度(du)黨政機(ji)(ji)關公務用(yong)車(che)選用(yong)車(che)型目(mu)錄(征求(qiu)意(yi)見稿)》為(wei)自主(zhu)(zhu)品牌擴大在政府采購的(de)(de)(de)市場份額,為(wei)改變(bian)目(mu)前國(guo)內政府采購以(yi)合(he)資品牌產品為(wei)主(zhu)(zhu)的(de)(de)(de)局面(mian)(mian)提(ti)供(gong)了保障。促進(jin)自主(zhu)(zhu)品牌發(fa)展(zhan)(zhan),國(guo)產汽(qi)(qi)(qi)車(che)業(ye)的(de)(de)(de)繁榮將(jiang)為(wei)汽(qi)(qi)(qi)車(che)膠(jiao)的(de)(de)(de)應(ying)用(yong)提(ti)供(gong)有(you)力保障。預測未來3年,我國(guo)室(shi)溫硫化(hua)硅橡(xiang)膠(jiao)在汽(qi)(qi)(qi)車(che)行業(ye)將(jiang)以(yi)年均(jun)20%增(zeng)(zeng)長(chang)(chang)。
此外,硅(gui)(gui)(gui)橡膠(jiao)(jiao)是重要的非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao),約占(zhan)非(fei)石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao)消(xiao)費(fei)量的98%。但(dan)因(yin)為石(shi)(shi)油(you)(you)價格(ge)的大(da)(da)幅上(shang)漲(zhang),同(tong)時(shi)我國(guo)在(zai)硅(gui)(gui)(gui)橡膠(jiao)(jiao)的關鍵原(yuan)料有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體的生產(chan)技(ji)術(shu)(shu)方面取(qu)得突破,有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體的生產(chan)技(ji)術(shu)(shu)在(zai)2005年前被幾家跨國(guo)公司壟(long)斷,但(dan)目前我國(guo)已發(fa)展成(cheng)(cheng)為全球有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)體第1大(da)(da)國(guo),這(zhe)2個方面原(yuan)因(yin)使硅(gui)(gui)(gui)橡膠(jiao)(jiao)的價格(ge)從2011年起開始低于石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao),僅約為大(da)(da)宗(zong)石(shi)(shi)油(you)(you)基橡膠(jiao)(jiao)的80%~90%,成(cheng)(cheng)為廉價的合(he)成(cheng)(cheng)橡膠(jiao)(jiao),并開始大(da)(da)規模(mo)替代石(shi)(shi)油(you)(you)基合(he)成(cheng)(cheng)橡膠(jiao)(jiao)。這(zhe)將極大(da)(da)拓展有(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)業(ye)的市場空間,同(tong)時(shi)將帶動硅(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)樹脂等其他有(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)品的消(xiao)費(fei)。