硅橡膠是指主(zhu)鏈由(you)硅和(he)氧原子交(jiao)替構成(cheng),硅原子上(shang)通(tong)常連有(you)(you)兩個有(you)(you)機基(ji)(ji)(ji)團的(de)(de)橡(xiang)(xiang)膠(jiao)。普通(tong)的(de)(de)硅橡(xiang)(xiang)膠(jiao)主(zhu)要由(you)含甲基(ji)(ji)(ji)和(he)少(shao)量(liang)乙烯基(ji)(ji)(ji)的(de)(de)硅氧鏈節組成(cheng)。苯基(ji)(ji)(ji)的(de)(de)引(yin)入可(ke)(ke)提(ti)高硅橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)高、低溫性(xing)能(neng),三(san)氟(fu)丙基(ji)(ji)(ji)及氰基(ji)(ji)(ji)的(de)(de)引(yin)入則可(ke)(ke)提(ti)高硅橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)溫及耐(nai)油性(xing)能(neng)。硅橡(xiang)(xiang)膠(jiao)耐(nai)低溫性(xing)能(neng)良(liang)好,一般在-55℃下仍能(neng)工(gong)作。引(yin)入苯基(ji)(ji)(ji)后(hou),可(ke)(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)熱性(xing)能(neng)也很突出(chu),在180℃下可(ke)(ke)長期工(gong)作,稍高于(yu)200℃也能(neng)承受(shou)數周(zhou)或更(geng)長時(shi)間(jian)仍有(you)(you)彈性(xing),瞬時(shi)可(ke)(ke)耐(nai)300℃以上(shang)的(de)(de)高溫。硅橡(xiang)(xiang)膠(jiao)的(de)(de)透氣性(xing)好,氧氣透過率在合成(cheng)聚(ju)合物中是較高的(de)(de)。此外,硅橡(xiang)(xiang)膠(jiao)還具有(you)(you)生理惰性(xing)、不會導(dao)致凝血的(de)(de)突出(chu)特性(xing),因此在醫(yi)用領域(yu)應用廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠分(fen)類的方法(fa)很多,通常按固化(hua)前的形態分(fen)為(wei)(wei)固體(ti)硅(gui)(gui)橡(xiang)(xiang)膠和液(ye)體(ti)硅(gui)(gui)橡(xiang)(xiang)膠;按硫(liu)(liu)化(hua)溫(wen)(wen)度分(fen)為(wei)(wei)室溫(wen)(wen)硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)(xiang)膠,高溫(wen)(wen)硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)(xiang)膠;按所用(yong)單體(ti)的不同,可(ke)分(fen)為(wei)(wei)甲基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)(xiang)膠,甲基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)橡(xiang)(xiang)膠、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)膠等(deng);按性(xing)能(neng)和用(yong)途(tu)的不同又可(ke)分(fen)為(wei)(wei)通用(yong)型、超耐(nai)(nai)低溫(wen)(wen)型、超耐(nai)(nai)高溫(wen)(wen)型、高強力型、耐(nai)(nai)油型、醫用(yong)型等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)(guo)以三(san)氯化(hua)鐵為(wei)催化(hua)劑合成的(de)(de)(de)。1945年(nian),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)品(pin)問(wen)世(shi)。1948年(nian),采用高比表面積的(de)(de)(de)氣相法白炭黑補強(qiang)的(de)(de)(de)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成功(gong),使硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)性能躍升到(dao)實用階段,奠定了現代硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)技(ji)術的(de)(de)(de)基礎。從二甲基二氯硅(gui)烷合成開始生產(chan)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)國(guo)(guo)家(jia)有美國(guo)(guo)。俄(e)羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)工業(ye)化(hua)研(yan)究(jiu)始于1957年(nian),多家(jia)研(yan)究(jiu)所和企業(ye)陸續開發出各種硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底(di),中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)能力為(wei)135千(qian)噸,其中(zhong)高溫膠(jiao)(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫硫(liu)(liu)化硅(gui)橡(xiang)膠(jiao)(jiao)是指聚硅(gui)氧烷變成(cheng)(cheng)(cheng)彈性體的(de)過(guo)程(cheng)是經過(guo)高溫(110-170℃)硫(liu)(liu)化成(cheng)(cheng)(cheng)型的(de)。它主要(yao)以高分子量(liang)的(de)聚甲基(ji)乙烯基(ji)硅(gui)氧烷為(wei)(wei)生膠(jiao)(jiao),混(hun)入(ru)補(bu)強填料、硫(liu)(liu)化劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓下(xia)硫(liu)(liu)化成(cheng)(cheng)(cheng)彈性體。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)補(bu)強主要(yao)是各(ge)(ge)種類(lei)型的(de)白炭黑,可(ke)使硫(liu)(liu)化膠(jiao)(jiao)的(de)強度增加(jia)(jia)數(shu)十倍(bei)。有時為(wei)(wei)了降低成(cheng)(cheng)(cheng)本或(huo)改善膠(jiao)(jiao)料性能(neng)及賦予(yu)硫(liu)(liu)化膠(jiao)(jiao)各(ge)(ge)種特(te)殊的(de)性能(neng),也加(jia)(jia)入(ru)相應的(de)各(ge)(ge)種添加(jia)(jia)劑(ji)。硫(liu)(liu)化劑(ji)是各(ge)(ge)種有機過(guo)氧化物(wu)或(huo)加(jia)(jia)成(cheng)(cheng)(cheng)反應催(cui)化劑(ji)。
加工成型方法(fa)如圖所(suo)示。一次(ci)硫化(hua)的目(mu)的是(shi)進行高分子鏈的交(jiao)聯反應;二(er)次(ci)硫化(hua)的目(mu)的是(shi)進行補充(chong)交(jiao)聯、驅除硫化(hua)劑分解產物和其(qi)他(ta)揮(hui)發性(xing)化(hua)合物以穩(wen)定硫化(hua)膠的各項性(xing)能。常用的設備有開放式(shi)煉膠機、捏合機及真空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡膠(jiao)(jiao)(jiao)顯(xian)著(zhu)的(de)(de)(de)特(te)征是高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅是天然(ran)橡膠(jiao)(jiao)(jiao)或某些合成橡膠(jiao)(jiao)(jiao)的(de)(de)(de)一半,但(dan)在200℃以(yi)上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環(huan)境下(xia),硅(gui)(gui)橡膠(jiao)(jiao)(jiao)仍能(neng)(neng)保持(chi)一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)(wu)明顯(xian)變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)度(du)一般為(wei)(wei)-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)(xing)能(neng)(neng)優異。這對航空、宇航工業的(de)(de)(de)意義重大(da)。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及(ji)紫外線等(deng)(deng)十分(fen)穩定(ding),在不加任何添(tian)加劑(ji)(ji)的(de)(de)(de)情況(kuang)下(xia),就(jiu)具有優良的(de)(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡膠(jiao)(jiao)(jiao)具有優異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡膠(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)下(xia)的(de)(de)(de)物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)(tong)用(yong)(yong)橡膠(jiao)(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下(xia),其物(wu)(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通(tong)(tong)用(yong)(yong)橡膠(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及(ji)化學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)(tong)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)具有中等(deng)(deng)的(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)對空氣、氮、氧(yang)、二氧(yang)化碳(tan)等(deng)(deng)氣體(ti)(ti)的(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡膠(jiao)(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡膠(jiao)(jiao)(jiao)無(wu)(wu)毒(du),無(wu)(wu)味(wei),無(wu)(wu)嗅,與人體(ti)(ti)組(zu)織不粘連,具有抗凝血作用(yong)(yong),對肌體(ti)(ti)組(zu)織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別(bie)適(shi)合作為(wei)(wei)醫用(yong)(yong)材料。
硅橡膠的用量
據中(zhong)國(guo)汽(qi)(qi)車(che)(che)(che)工業(ye)協會統計(ji),2012年(nian)(nian)(nian),汽(qi)(qi)車(che)(che)(che)產銷分別(bie)達到1927.18萬輛和1930.64萬輛,同(tong)比(bi)分別(bie)增長4.63%和4.33%,汽(qi)(qi)車(che)(che)(che)工業(ye)硅橡(xiang)膠的(de)(de)(de)(de)用(yong)量約達2.0萬t。根據觀研天(tian)下的(de)(de)(de)(de)新(xin)研究,增加(jia)有機硅材料在(zai)汽(qi)(qi)車(che)(che)(che)零(ling)部(bu)件方面的(de)(de)(de)(de)用(yong)量,可以(yi)大幅度提(ti)(ti)高汽(qi)(qi)車(che)(che)(che)的(de)(de)(de)(de)安全性能,因此,汽(qi)(qi)車(che)(che)(che)產量和單(dan)車(che)(che)(che)用(yong)量水平的(de)(de)(de)(de)提(ti)(ti)高都將推動汽(qi)(qi)車(che)(che)(che)工業(ye)對硅橡(xiang)膠需求的(de)(de)(de)(de)增加(jia)。國(guo)家鼓勵自主(zhu)(zhu)品(pin)牌(pai)的(de)(de)(de)(de)汽(qi)(qi)車(che)(che)(che)發展,關(guan)(guan)鍵(jian)汽(qi)(qi)車(che)(che)(che)零(ling)部(bu)件實現自主(zhu)(zhu)化,《2012年(nian)(nian)(nian)度黨(dang)政機關(guan)(guan)公務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型(xing)目錄(征求意見稿(gao))》為(wei)(wei)自主(zhu)(zhu)品(pin)牌(pai)擴大在(zai)政府(fu)采購(gou)的(de)(de)(de)(de)市場份額(e),為(wei)(wei)改(gai)變目前國(guo)內政府(fu)采購(gou)以(yi)合資品(pin)牌(pai)產品(pin)為(wei)(wei)主(zhu)(zhu)的(de)(de)(de)(de)局面提(ti)(ti)供了保(bao)障。促(cu)進(jin)自主(zhu)(zhu)品(pin)牌(pai)發展,國(guo)產汽(qi)(qi)車(che)(che)(che)業(ye)的(de)(de)(de)(de)繁(fan)榮將為(wei)(wei)汽(qi)(qi)車(che)(che)(che)膠的(de)(de)(de)(de)應(ying)用(yong)提(ti)(ti)供有力保(bao)障。預(yu)測未來3年(nian)(nian)(nian),我國(guo)室溫硫化硅橡(xiang)膠在(zai)汽(qi)(qi)車(che)(che)(che)行業(ye)將以(yi)年(nian)(nian)(nian)均20%增長。
此外,硅(gui)橡(xiang)(xiang)膠(jiao)是重要的非(fei)(fei)石(shi)(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),約占非(fei)(fei)石(shi)(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)消(xiao)費(fei)量的98%。但因為(wei)石(shi)(shi)油(you)價格的大幅上漲,同時我(wo)國在硅(gui)橡(xiang)(xiang)膠(jiao)的關(guan)鍵原料(liao)有機硅(gui)單體(ti)的生(sheng)(sheng)產技術方面取(qu)得突(tu)破,有機硅(gui)單體(ti)的生(sheng)(sheng)產技術在2005年(nian)前被幾家(jia)跨國公司壟斷,但目前我(wo)國已(yi)發(fa)展(zhan)成(cheng)(cheng)為(wei)全球有機硅(gui)單體(ti)第(di)1大國,這2個方面原因使(shi)硅(gui)橡(xiang)(xiang)膠(jiao)的價格從2011年(nian)起開(kai)始低于(yu)石(shi)(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),僅(jin)約為(wei)大宗(zong)石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)(cheng)為(wei)廉價的合(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao),并開(kai)始大規模替代石(shi)(shi)油(you)基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)。這將極大拓展(zhan)有機硅(gui)產業(ye)的市(shi)場空間(jian),同時將帶動硅(gui)油(you)、硅(gui)烷偶聯(lian)劑和硅(gui)樹脂等其他有機硅(gui)產品的消(xiao)費(fei)。