
硅橡膠是指(zhi)主鏈由(you)硅(gui)和氧原子交替構成,硅(gui)原子上(shang)通常連有兩個有機基(ji)團的(de)(de)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。普(pu)通的(de)(de)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)主要由(you)含甲(jia)基(ji)和少(shao)量乙烯(xi)基(ji)的(de)(de)硅(gui)氧鏈節(jie)組成。苯基(ji)的(de)(de)引(yin)入可提高(gao)(gao)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐(nai)(nai)高(gao)(gao)、低溫(wen)性(xing)(xing)能(neng),三(san)氟丙基(ji)及(ji)氰基(ji)的(de)(de)引(yin)入則(ze)可提高(gao)(gao)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐(nai)(nai)溫(wen)及(ji)耐(nai)(nai)油性(xing)(xing)能(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)耐(nai)(nai)低溫(wen)性(xing)(xing)能(neng)良好,一般在(zai)-55℃下仍能(neng)工(gong)作(zuo)。引(yin)入苯基(ji)后(hou),可達(da)-73℃。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐(nai)(nai)熱(re)性(xing)(xing)能(neng)也(ye)很突(tu)出,在(zai)180℃下可長期工(gong)作(zuo),稍(shao)高(gao)(gao)于200℃也(ye)能(neng)承受數周(zhou)或更(geng)長時間仍有彈性(xing)(xing),瞬時可耐(nai)(nai)300℃以(yi)上(shang)的(de)(de)高(gao)(gao)溫(wen)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)透氣(qi)性(xing)(xing)好,氧氣(qi)透過率在(zai)合成聚合物中是較高(gao)(gao)的(de)(de)。此外(wai),硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)還(huan)具有生理惰(duo)性(xing)(xing)、不會(hui)導(dao)致(zhi)凝血的(de)(de)突(tu)出特性(xing)(xing),因此在(zai)醫用領(ling)域應(ying)用廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)分類(lei)的(de)方法很多,通常按固(gu)化(hua)(hua)前的(de)形態分為(wei)固(gu)體(ti)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)和(he)液(ye)體(ti)硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按硫(liu)(liu)化(hua)(hua)溫(wen)度分為(wei)室溫(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao),高(gao)溫(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按所(suo)用單(dan)體(ti)的(de)不(bu)(bu)同,可分為(wei)甲基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)等;按性(xing)能和(he)用途的(de)不(bu)(bu)同又可分為(wei)通用型、超(chao)耐低溫(wen)型、超(chao)耐高(gao)溫(wen)型、高(gao)強力型、耐油型、醫(yi)用型等等。
發展史
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期是由(you)美(mei)國(guo)以三氯化(hua)(hua)鐵為催化(hua)(hua)劑合成的(de)。1945年(nian)(nian),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品問世。1948年(nian)(nian),采用高比表面積的(de)氣相法(fa)白炭黑補強(qiang)的(de)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)研制(zhi)成功,使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)性(xing)能(neng)(neng)躍(yue)升(sheng)到實用階段(duan),奠定了現(xian)代硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)技術的(de)基礎。從二(er)甲(jia)基二(er)氯硅(gui)(gui)烷合成開始(shi)生產(chan)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)家有(you)美(mei)國(guo)。俄羅斯、德國(guo)、日(ri)本、韓國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)工業化(hua)(hua)研究(jiu)始(shi)于1957年(nian)(nian),多(duo)家研究(jiu)所和(he)企(qi)業陸續開發(fa)出各種硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)(nian)底,中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)能(neng)(neng)力為135千噸,其中(zhong)高溫膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)化(hua)(hua)硅橡膠是指聚(ju)(ju)硅氧(yang)烷變成(cheng)彈性體(ti)的(de)(de)(de)過(guo)程是經過(guo)高(gao)溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)型(xing)的(de)(de)(de)。它主要以高(gao)分子量的(de)(de)(de)聚(ju)(ju)甲基乙(yi)烯基硅氧(yang)烷為(wei)生(sheng)膠,混入補(bu)強(qiang)填(tian)料(liao)、硫(liu)(liu)化(hua)(hua)劑等,在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)彈性體(ti)。硅橡膠的(de)(de)(de)補(bu)強(qiang)主要是各(ge)種(zhong)類型(xing)的(de)(de)(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)膠的(de)(de)(de)強(qiang)度增(zeng)加(jia)數十倍。有時為(wei)了降低成(cheng)本或(huo)改善膠料(liao)性能(neng)及(ji)賦予(yu)硫(liu)(liu)化(hua)(hua)膠各(ge)種(zhong)特殊的(de)(de)(de)性能(neng),也(ye)加(jia)入相應(ying)(ying)的(de)(de)(de)各(ge)種(zhong)添加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是各(ge)種(zhong)有機過(guo)氧(yang)化(hua)(hua)物或(huo)加(jia)成(cheng)反應(ying)(ying)催(cui)化(hua)(hua)劑。
加工成型(xing)方法如圖所示(shi)。一次硫(liu)(liu)(liu)化(hua)的(de)目(mu)的(de)是進行(xing)高分子鏈的(de)交(jiao)聯反應;二(er)次硫(liu)(liu)(liu)化(hua)的(de)目(mu)的(de)是進行(xing)補充交(jiao)聯、驅除硫(liu)(liu)(liu)化(hua)劑分解產物和其他揮發性化(hua)合物以穩定硫(liu)(liu)(liu)化(hua)膠(jiao)的(de)各項(xiang)性能。常用的(de)設備有開放式煉膠(jiao)機(ji)、捏合機(ji)及真空(kong)密煉機(ji)。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)特(te)征是高溫(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)下硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)強度僅是天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)一半,但在200℃以上的(de)(de)高溫(wen)(wen)環境(jing)下,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一定(ding)的(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度,且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)(wu)明(ming)顯變化(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃(li)化(hua)溫(wen)(wen)度一般為(wei)-70~-50℃,特(te)殊配方可達(da)-100℃,表明(ming)其低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)異。這(zhe)對(dui)航空、宇航工業(ye)的(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧、臭氧及紫外線等十分(fen)穩(wen)定(ding),在不(bu)加(jia)任何添加(jia)劑(ji)的(de)(de)情況下,就具(ju)(ju)有優(you)良的(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)電暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下的(de)(de)物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)(de)高溫(wen)(wen)和(he)(he)-50℃的(de)(de)低(di)溫(wen)(wen)下,其物理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有中等的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧、二氧化(hua)碳(tan)等氣(qi)體(ti)的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)高出(chu)30-50倍。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)(wu)毒(du),無(wu)(wu)味(wei),無(wu)(wu)嗅(xiu),與(yu)人體(ti)組織(zhi)不(bu)粘(zhan)連,具(ju)(ju)有抗(kang)凝血作用(yong),對(dui)肌體(ti)組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少(shao)。特(te)別(bie)適合(he)作為(wei)醫(yi)用(yong)材料。
硅橡膠的用量
據中(zhong)國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)工業協會統計(ji),2012年,汽(qi)(qi)(qi)車(che)(che)產銷分別(bie)(bie)達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比分別(bie)(bie)增(zeng)(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)工業硅橡膠(jiao)的(de)用(yong)量約達2.0萬(wan)t。根(gen)據觀研天下的(de)新(xin)研究,增(zeng)(zeng)加有機(ji)(ji)硅材料在(zai)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(fu)度(du)提高(gao)(gao)汽(qi)(qi)(qi)車(che)(che)的(de)安全性(xing)能,因此,汽(qi)(qi)(qi)車(che)(che)產量和單車(che)(che)用(yong)量水平的(de)提高(gao)(gao)都將(jiang)(jiang)(jiang)推動(dong)汽(qi)(qi)(qi)車(che)(che)工業對硅橡膠(jiao)需求的(de)增(zeng)(zeng)加。國(guo)(guo)家(jia)鼓(gu)勵自(zi)主品(pin)(pin)(pin)牌(pai)的(de)汽(qi)(qi)(qi)車(che)(che)發展,關鍵(jian)汽(qi)(qi)(qi)車(che)(che)零部件實現(xian)自(zi)主化,《2012年度(du)黨政(zheng)(zheng)機(ji)(ji)關公務用(yong)車(che)(che)選用(yong)車(che)(che)型(xing)目錄(征求意(yi)見稿)》為自(zi)主品(pin)(pin)(pin)牌(pai)擴大(da)在(zai)政(zheng)(zheng)府采購的(de)市(shi)場份額,為改(gai)變目前國(guo)(guo)內政(zheng)(zheng)府采購以(yi)合資品(pin)(pin)(pin)牌(pai)產品(pin)(pin)(pin)為主的(de)局面(mian)提供(gong)了保障(zhang)(zhang)。促進自(zi)主品(pin)(pin)(pin)牌(pai)發展,國(guo)(guo)產汽(qi)(qi)(qi)車(che)(che)業的(de)繁榮將(jiang)(jiang)(jiang)為汽(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)應用(yong)提供(gong)有力保障(zhang)(zhang)。預測未來3年,我(wo)國(guo)(guo)室溫硫化硅橡膠(jiao)在(zai)汽(qi)(qi)(qi)車(che)(che)行業將(jiang)(jiang)(jiang)以(yi)年均20%增(zeng)(zeng)長(chang)。
此外,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)是重要的非石(shi)(shi)油(you)(you)(you)基合成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao),約(yue)占非石(shi)(shi)油(you)(you)(you)基合成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)消(xiao)(xiao)費(fei)量的98%。但因為(wei)石(shi)(shi)油(you)(you)(you)價(jia)格(ge)的大(da)幅上漲,同(tong)(tong)時我(wo)國(guo)(guo)在硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)的關鍵原料有(you)機硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)的生產(chan)技(ji)術方面(mian)取得(de)突(tu)破,有(you)機硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)的生產(chan)技(ji)術在2005年(nian)前被幾家跨國(guo)(guo)公司壟(long)斷,但目前我(wo)國(guo)(guo)已發(fa)展(zhan)成(cheng)(cheng)(cheng)(cheng)為(wei)全(quan)球有(you)機硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)第1大(da)國(guo)(guo),這2個方面(mian)原因使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)的價(jia)格(ge)從2011年(nian)起開始(shi)(shi)低(di)于石(shi)(shi)油(you)(you)(you)基合成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao),僅約(yue)為(wei)大(da)宗(zong)石(shi)(shi)油(you)(you)(you)基橡(xiang)膠(jiao)的80%~90%,成(cheng)(cheng)(cheng)(cheng)為(wei)廉價(jia)的合成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao),并開始(shi)(shi)大(da)規模替代(dai)石(shi)(shi)油(you)(you)(you)基合成(cheng)(cheng)(cheng)(cheng)橡(xiang)膠(jiao)。這將極大(da)拓展(zhan)有(you)機硅(gui)(gui)(gui)(gui)(gui)產(chan)業(ye)的市場空間,同(tong)(tong)時將帶動(dong)硅(gui)(gui)(gui)(gui)(gui)油(you)(you)(you)、硅(gui)(gui)(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)(gui)(gui)樹(shu)脂(zhi)等其他(ta)有(you)機硅(gui)(gui)(gui)(gui)(gui)產(chan)品的消(xiao)(xiao)費(fei)。