硅橡膠是(shi)指主鏈由硅和(he)氧原(yuan)子(zi)交替(ti)構(gou)成,硅原(yuan)子(zi)上(shang)通(tong)常連有兩個(ge)有機基(ji)(ji)(ji)(ji)團(tuan)的橡(xiang)膠(jiao)。普通(tong)的硅橡(xiang)膠(jiao)主要(yao)由含甲基(ji)(ji)(ji)(ji)和(he)少量乙烯基(ji)(ji)(ji)(ji)的硅氧鏈節組(zu)成。苯基(ji)(ji)(ji)(ji)的引入可(ke)(ke)提高(gao)(gao)硅橡(xiang)膠(jiao)的耐(nai)高(gao)(gao)、低溫性(xing)(xing)能(neng),三氟(fu)丙基(ji)(ji)(ji)(ji)及氰(qing)基(ji)(ji)(ji)(ji)的引入則可(ke)(ke)提高(gao)(gao)硅橡(xiang)膠(jiao)的耐(nai)溫及耐(nai)油(you)性(xing)(xing)能(neng)。硅橡(xiang)膠(jiao)耐(nai)低溫性(xing)(xing)能(neng)良好,一般在-55℃下仍(reng)能(neng)工作。引入苯基(ji)(ji)(ji)(ji)后,可(ke)(ke)達-73℃。硅橡(xiang)膠(jiao)的耐(nai)熱(re)性(xing)(xing)能(neng)也很突(tu)出,在180℃下可(ke)(ke)長(chang)期工作,稍(shao)高(gao)(gao)于200℃也能(neng)承受數周或(huo)更長(chang)時(shi)間仍(reng)有彈性(xing)(xing),瞬時(shi)可(ke)(ke)耐(nai)300℃以上(shang)的高(gao)(gao)溫。硅橡(xiang)膠(jiao)的透氣性(xing)(xing)好,氧氣透過率在合成聚合物中是(shi)較高(gao)(gao)的。此(ci)外,硅橡(xiang)膠(jiao)還具有生(sheng)理惰性(xing)(xing)、不會導致(zhi)凝血的突(tu)出特性(xing)(xing),因此(ci)在醫用領域(yu)應用廣泛。
主要(yao)品(pin)種
硅(gui)(gui)(gui)橡(xiang)膠分(fen)類的方法很多,通(tong)(tong)常按(an)固化前(qian)的形(xing)態分(fen)為(wei)固體(ti)硅(gui)(gui)(gui)橡(xiang)膠和液體(ti)硅(gui)(gui)(gui)橡(xiang)膠;按(an)硫化溫度分(fen)為(wei)室溫硫化硅(gui)(gui)(gui)橡(xiang)膠,高(gao)溫硫化硅(gui)(gui)(gui)橡(xiang)膠;按(an)所用(yong)單體(ti)的不(bu)同,可分(fen)為(wei)甲基乙烯(xi)基硅(gui)(gui)(gui)橡(xiang)膠,甲基苯基乙烯(xi)基硅(gui)(gui)(gui)橡(xiang)膠、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠等;按(an)性能和用(yong)途的不(bu)同又可分(fen)為(wei)通(tong)(tong)用(yong)型(xing)(xing)、超耐(nai)(nai)低(di)溫型(xing)(xing)、超耐(nai)(nai)高(gao)溫型(xing)(xing)、高(gao)強力型(xing)(xing)、耐(nai)(nai)油(you)型(xing)(xing)、醫用(yong)型(xing)(xing)等等。
發展史(shi)
硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)早期(qi)是(shi)由美(mei)國(guo)(guo)以(yi)三氯化鐵為催化劑合成(cheng)的(de)。1945年,硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)產(chan)品問世。1948年,采用高比(bi)表面積的(de)氣相法白炭黑補(bu)強的(de)硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)研(yan)制成(cheng)功,使硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)性能躍升到(dao)實(shi)用階段,奠定了(le)現(xian)代硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)生產(chan)技(ji)術的(de)基礎。從二甲基二氯硅(gui)(gui)(gui)(gui)(gui)(gui)烷合成(cheng)開始(shi)生產(chan)硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)國(guo)(guo)家有(you)美(mei)國(guo)(guo)。俄(e)羅斯(si)、德(de)國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)(zhong)國(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)的(de)工業化研(yan)究(jiu)始(shi)于1957年,多(duo)家研(yan)究(jiu)所和企業陸(lu)續開發出各(ge)種硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)。到(dao)2003年底,中(zhong)(zhong)國(guo)(guo)硅(gui)(gui)(gui)(gui)(gui)(gui)橡膠(jiao)(jiao)生產(chan)能力(li)為135千(qian)噸(dun),其中(zhong)(zhong)高溫(wen)膠(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)化(hua)(hua)硅橡膠(jiao)是(shi)指聚硅氧(yang)烷變成(cheng)彈性(xing)體的(de)(de)(de)過(guo)程是(shi)經過(guo)高(gao)溫(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)型的(de)(de)(de)。它主要以(yi)高(gao)分子量的(de)(de)(de)聚甲(jia)基乙(yi)烯基硅氧(yang)烷為生膠(jiao),混入補強填料、硫(liu)(liu)化(hua)(hua)劑等(deng),在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)彈性(xing)體。硅橡膠(jiao)的(de)(de)(de)補強主要是(shi)各種(zhong)類(lei)型的(de)(de)(de)白炭黑(hei),可使硫(liu)(liu)化(hua)(hua)膠(jiao)的(de)(de)(de)強度(du)增加(jia)數十倍。有(you)時為了降(jiang)低成(cheng)本或改善膠(jiao)料性(xing)能及賦予硫(liu)(liu)化(hua)(hua)膠(jiao)各種(zhong)特殊(shu)的(de)(de)(de)性(xing)能,也加(jia)入相應(ying)的(de)(de)(de)各種(zhong)添加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是(shi)各種(zhong)有(you)機過(guo)氧(yang)化(hua)(hua)物(wu)或加(jia)成(cheng)反應(ying)催化(hua)(hua)劑。
加工成型方(fang)法如圖(tu)所示。一次硫化(hua)的(de)目的(de)是進(jin)行高(gao)分(fen)子(zi)鏈的(de)交聯反應;二次硫化(hua)的(de)目的(de)是進(jin)行補充交聯、驅除(chu)硫化(hua)劑(ji)分(fen)解(jie)產物(wu)和其他揮發性化(hua)合物(wu)以穩定硫化(hua)膠的(de)各項性能。常用的(de)設備(bei)有開(kai)放式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性(xing)能
(1)高(gao)(gao)(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)(de)特(te)(te)征是高(gao)(gao)(gao)溫(wen)(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅是天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一半,但(dan)在(zai)200℃以上的(de)(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)保持一定(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明(ming)顯(xian)變化。(2)低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)(wen)度(du)一般(ban)為-70~-50℃,特(te)(te)殊配方可達-100℃,表明(ming)其低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)異(yi)。這對(dui)(dui)航空、宇航工(gong)業的(de)(de)(de)(de)(de)意義(yi)重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)(dui)氧、臭氧及紫(zi)外線等十分穩(wen)定(ding),在(zai)不(bu)加任何添加劑的(de)(de)(de)(de)(de)情(qing)況下,就具(ju)有(you)優(you)(you)良的(de)(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)優(you)(you)異(yi)的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)電(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)也(ye)非(fei)常(chang)好。(5)物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下的(de)(de)(de)(de)(de)物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)(wen)和(he)(he)-50℃的(de)(de)(de)(de)(de)低(di)(di)溫(wen)(wen)(wen)下,其物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)于(yu)通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)油及化學(xue)試劑性(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)中等的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)(qi)、氮、氧、二氧化碳等氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)(de)(de)(de)透氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)(gao)(gao)出(chu)30-50倍。(8)生(sheng)理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)(ti)組織不(bu)粘連,具(ju)有(you)抗凝血(xue)作用(yong),對(dui)(dui)肌體(ti)(ti)組織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)(te)別適(shi)合作為醫用(yong)材(cai)料。
硅(gui)橡(xiang)膠(jiao)的用量
據中國(guo)汽(qi)車(che)工(gong)(gong)業(ye)(ye)(ye)協會統計,2012年(nian),汽(qi)車(che)產(chan)銷(xiao)分別達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分別增(zeng)(zeng)長4.63%和4.33%,汽(qi)車(che)工(gong)(gong)業(ye)(ye)(ye)硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)用量(liang)約達2.0萬t。根據觀研天下(xia)的(de)(de)(de)新研究,增(zeng)(zeng)加有(you)機(ji)硅材料(liao)在汽(qi)車(che)零(ling)(ling)部(bu)件(jian)方面(mian)(mian)的(de)(de)(de)用量(liang),可(ke)以(yi)大幅度(du)提(ti)高汽(qi)車(che)的(de)(de)(de)安全性能,因(yin)此,汽(qi)車(che)產(chan)量(liang)和單(dan)車(che)用量(liang)水平的(de)(de)(de)提(ti)高都將(jiang)推動汽(qi)車(che)工(gong)(gong)業(ye)(ye)(ye)對硅橡(xiang)膠(jiao)(jiao)需求的(de)(de)(de)增(zeng)(zeng)加。國(guo)家鼓勵自(zi)(zi)主品(pin)牌(pai)的(de)(de)(de)汽(qi)車(che)發展(zhan)(zhan),關鍵汽(qi)車(che)零(ling)(ling)部(bu)件(jian)實現自(zi)(zi)主化,《2012年(nian)度(du)黨政(zheng)機(ji)關公務用車(che)選用車(che)型(xing)目錄(征求意見(jian)稿)》為(wei)自(zi)(zi)主品(pin)牌(pai)擴大在政(zheng)府采購(gou)的(de)(de)(de)市場份額,為(wei)改(gai)變(bian)目前國(guo)內政(zheng)府采購(gou)以(yi)合資品(pin)牌(pai)產(chan)品(pin)為(wei)主的(de)(de)(de)局面(mian)(mian)提(ti)供了保(bao)障。促進自(zi)(zi)主品(pin)牌(pai)發展(zhan)(zhan),國(guo)產(chan)汽(qi)車(che)業(ye)(ye)(ye)的(de)(de)(de)繁榮將(jiang)為(wei)汽(qi)車(che)膠(jiao)(jiao)的(de)(de)(de)應用提(ti)供有(you)力保(bao)障。預測未(wei)來(lai)3年(nian),我(wo)國(guo)室(shi)溫硫化硅橡(xiang)膠(jiao)(jiao)在汽(qi)車(che)行業(ye)(ye)(ye)將(jiang)以(yi)年(nian)均20%增(zeng)(zeng)長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要(yao)的非(fei)石(shi)油基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非(fei)石(shi)油基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)量的98%。但因為(wei)石(shi)油價格的大幅上(shang)漲(zhang),同(tong)時我(wo)國(guo)在硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的關(guan)鍵原(yuan)料有(you)(you)機硅(gui)(gui)單體(ti)的生(sheng)(sheng)產(chan)(chan)技術(shu)方面取(qu)得突破,有(you)(you)機硅(gui)(gui)單體(ti)的生(sheng)(sheng)產(chan)(chan)技術(shu)在2005年(nian)前被幾家跨國(guo)公司壟斷,但目前我(wo)國(guo)已發展成(cheng)(cheng)為(wei)全球有(you)(you)機硅(gui)(gui)單體(ti)第1大國(guo),這2個方面原(yuan)因使(shi)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的價格從(cong)2011年(nian)起開(kai)始低于石(shi)油基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅約為(wei)大宗石(shi)油基橡(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)(cheng)為(wei)廉(lian)價的合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開(kai)始大規模替(ti)代石(shi)油基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將極大拓展有(you)(you)機硅(gui)(gui)產(chan)(chan)業(ye)的市場空間,同(tong)時將帶動硅(gui)(gui)油、硅(gui)(gui)烷偶(ou)聯劑和硅(gui)(gui)樹(shu)脂等其他(ta)有(you)(you)機硅(gui)(gui)產(chan)(chan)品(pin)的消費(fei)。