
硅橡膠是(shi)指主鏈由硅和氧原(yuan)子(zi)交替構(gou)成(cheng),硅原(yuan)子(zi)上通常連(lian)有(you)兩個有(you)機基(ji)團的(de)(de)(de)橡(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)(de)硅橡(xiang)膠(jiao)(jiao)(jiao)主要由含甲基(ji)和少量乙烯基(ji)的(de)(de)(de)硅氧鏈節組成(cheng)。苯基(ji)的(de)(de)(de)引(yin)入可(ke)提高(gao)(gao)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐高(gao)(gao)、低溫性(xing)(xing)(xing)能(neng),三氟丙基(ji)及(ji)氰基(ji)的(de)(de)(de)引(yin)入則可(ke)提高(gao)(gao)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐溫及(ji)耐油性(xing)(xing)(xing)能(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)耐低溫性(xing)(xing)(xing)能(neng)良好,一般在(zai)-55℃下(xia)仍能(neng)工(gong)作。引(yin)入苯基(ji)后(hou),可(ke)達-73℃。硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐熱性(xing)(xing)(xing)能(neng)也很(hen)突出(chu),在(zai)180℃下(xia)可(ke)長期(qi)工(gong)作,稍(shao)高(gao)(gao)于200℃也能(neng)承受數周或(huo)更長時(shi)間仍有(you)彈性(xing)(xing)(xing),瞬時(shi)可(ke)耐300℃以(yi)上的(de)(de)(de)高(gao)(gao)溫。硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)透氣性(xing)(xing)(xing)好,氧氣透過率在(zai)合成(cheng)聚合物中是(shi)較高(gao)(gao)的(de)(de)(de)。此外,硅橡(xiang)膠(jiao)(jiao)(jiao)還具有(you)生(sheng)理惰(duo)性(xing)(xing)(xing)、不會導致凝血的(de)(de)(de)突出(chu)特性(xing)(xing)(xing),因此在(zai)醫(yi)用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)分(fen)(fen)類(lei)的(de)方法很(hen)多,通常(chang)按(an)(an)固(gu)化(hua)前的(de)形(xing)態分(fen)(fen)為固(gu)體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)和液體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)硫(liu)化(hua)溫度分(fen)(fen)為室溫硫(liu)化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),高溫硫(liu)化(hua)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按(an)(an)所用(yong)(yong)(yong)(yong)單體的(de)不(bu)同(tong),可(ke)分(fen)(fen)為甲基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)等;按(an)(an)性(xing)能和用(yong)(yong)(yong)(yong)途的(de)不(bu)同(tong)又可(ke)分(fen)(fen)為通用(yong)(yong)(yong)(yong)型(xing)、超(chao)耐(nai)低溫型(xing)、超(chao)耐(nai)高溫型(xing)、高強力(li)型(xing)、耐(nai)油型(xing)、醫用(yong)(yong)(yong)(yong)型(xing)等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)早期是由美(mei)國(guo)以三氯(lv)化鐵為催(cui)化劑(ji)合(he)成(cheng)的(de)。1945年,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)產(chan)品問世。1948年,采用(yong)高比表(biao)面積的(de)氣相(xiang)法(fa)白炭黑補強(qiang)的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)研制成(cheng)功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)性能(neng)(neng)躍(yue)升(sheng)到實用(yong)階段,奠定了現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)產(chan)技術的(de)基(ji)礎。從二(er)甲(jia)基(ji)二(er)氯(lv)硅(gui)(gui)烷合(he)成(cheng)開始(shi)生(sheng)產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)國(guo)家有美(mei)國(guo)。俄羅斯(si)、德國(guo)、日本、韓國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)工(gong)業化研究(jiu)(jiu)始(shi)于1957年,多家研究(jiu)(jiu)所(suo)和(he)企業陸(lu)續開發(fa)出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)。到2003年底,中(zhong)國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)產(chan)能(neng)(neng)力為135千噸(dun)(dun),其中(zhong)高溫膠(jiao)(jiao)100千噸(dun)(dun)。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)(liu)化(hua)(hua)硅(gui)橡膠(jiao)(jiao)是(shi)指聚(ju)硅(gui)氧(yang)烷變成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體的(de)(de)過(guo)程(cheng)是(shi)經過(guo)高(gao)溫(wen)(110-170℃)硫(liu)(liu)(liu)化(hua)(hua)成(cheng)(cheng)(cheng)型的(de)(de)。它主要以高(gao)分(fen)子量的(de)(de)聚(ju)甲基(ji)乙烯基(ji)硅(gui)氧(yang)烷為(wei)生膠(jiao)(jiao),混(hun)入補(bu)(bu)強填料(liao)、硫(liu)(liu)(liu)化(hua)(hua)劑等,在加(jia)熱(re)加(jia)壓下硫(liu)(liu)(liu)化(hua)(hua)成(cheng)(cheng)(cheng)彈(dan)性(xing)(xing)體。硅(gui)橡膠(jiao)(jiao)的(de)(de)補(bu)(bu)強主要是(shi)各(ge)種類型的(de)(de)白炭黑,可使硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)(jiao)的(de)(de)強度增加(jia)數(shu)十倍(bei)。有時為(wei)了降低成(cheng)(cheng)(cheng)本或(huo)改善膠(jiao)(jiao)料(liao)性(xing)(xing)能及賦予(yu)硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)(jiao)各(ge)種特殊的(de)(de)性(xing)(xing)能,也加(jia)入相(xiang)應的(de)(de)各(ge)種添(tian)加(jia)劑。硫(liu)(liu)(liu)化(hua)(hua)劑是(shi)各(ge)種有機過(guo)氧(yang)化(hua)(hua)物或(huo)加(jia)成(cheng)(cheng)(cheng)反應催化(hua)(hua)劑。
加工成型方(fang)法如圖所示。一(yi)次(ci)硫(liu)化(hua)的目的是(shi)進行高分(fen)子鏈(lian)的交聯(lian)(lian)反應;二次(ci)硫(liu)化(hua)的目的是(shi)進行補充交聯(lian)(lian)、驅(qu)除硫(liu)化(hua)劑分(fen)解產物和其他揮發性(xing)化(hua)合物以穩定硫(liu)化(hua)膠(jiao)的各項性(xing)能(neng)。常(chang)用的設備有開放(fang)式(shi)煉膠(jiao)機、捏合機及真空(kong)密煉機。
主要性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯(xian)著的(de)(de)(de)(de)特征(zheng)是(shi)高溫(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)下硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)強度僅(jin)是(shi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)一半(ban),但(dan)在200℃以上(shang)的(de)(de)(de)(de)高溫(wen)環境下,硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持(chi)一定(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度,且力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)(wu)明(ming)顯(xian)變(bian)化。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)玻璃化溫(wen)度一般為-70~-50℃,特殊(shu)配方可達(da)-100℃,表(biao)明(ming)其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)異。這對航(hang)空(kong)、宇航(hang)工業的(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中(zhong)Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及紫外線等十分(fen)穩(wen)定(ding),在不加任(ren)何(he)添(tian)加劑(ji)的(de)(de)(de)(de)情(qing)況下,就(jiu)具有(you)優(you)良的(de)(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具有(you)優(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非(fei)常好。(5)物(wu)理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常溫(wen)下的(de)(de)(de)(de)物(wu)理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)在150℃的(de)(de)(de)(de)高溫(wen)和-50℃的(de)(de)(de)(de)低溫(wen)下,其物(wu)理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)于(yu)通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)(nai)油(you)及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具有(you)中(zhong)等的(de)(de)(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)下硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對空(kong)氣(qi)(qi)(qi)、氮、氧(yang)、二氧(yang)化碳等氣(qi)(qi)(qi)體的(de)(de)(de)(de)透(tou)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高出30-50倍。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅,與人體組(zu)織不粘連,具有(you)抗凝血作用(yong)(yong),對肌體組(zu)織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特別適合作為醫用(yong)(yong)材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)協(xie)會(hui)統計(ji),2012年,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產銷分別達(da)到1927.18萬輛和1930.64萬輛,同比分別增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)硅(gui)橡(xiang)膠(jiao)的(de)用(yong)(yong)量約達(da)2.0萬t。根據觀研(yan)天下的(de)新(xin)研(yan)究(jiu),增(zeng)加有機硅(gui)材料在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)方面(mian)的(de)用(yong)(yong)量,可以大(da)幅度(du)(du)提高汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)的(de)安全性(xing)能(neng),因此,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產量和單車(che)(che)(che)用(yong)(yong)量水平的(de)提高都將推動(dong)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)對硅(gui)橡(xiang)膠(jiao)需求的(de)增(zeng)加。國家(jia)鼓勵(li)自主(zhu)品牌(pai)的(de)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)發展(zhan),關鍵汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)(bu)件(jian)實現自主(zhu)化,《2012年度(du)(du)黨政機關公務用(yong)(yong)車(che)(che)(che)選(xuan)用(yong)(yong)車(che)(che)(che)型(xing)目(mu)錄(征求意見稿)》為(wei)自主(zhu)品牌(pai)擴大(da)在政府采購的(de)市場份額,為(wei)改(gai)變目(mu)前國內政府采購以合資品牌(pai)產品為(wei)主(zhu)的(de)局面(mian)提供了保障。促進自主(zhu)品牌(pai)發展(zhan),國產汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)業(ye)(ye)的(de)繁榮將為(wei)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的(de)應用(yong)(yong)提供有力保障。預測(ce)未來3年,我國室溫硫(liu)化硅(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)行業(ye)(ye)將以年均20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重(zhong)要的(de)非石(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),約(yue)占(zhan)非石(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)(fei)量的(de)98%。但因為石(shi)油(you)(you)價格的(de)大(da)(da)幅(fu)上漲,同(tong)時我(wo)國在硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)關鍵原料有(you)機(ji)(ji)硅(gui)(gui)單(dan)(dan)體的(de)生產(chan)(chan)技術(shu)方(fang)面取得突破,有(you)機(ji)(ji)硅(gui)(gui)單(dan)(dan)體的(de)生產(chan)(chan)技術(shu)在2005年(nian)前被(bei)幾(ji)家跨國公司壟斷,但目前我(wo)國已發(fa)展成(cheng)為全(quan)球(qiu)有(you)機(ji)(ji)硅(gui)(gui)單(dan)(dan)體第1大(da)(da)國,這(zhe)(zhe)2個方(fang)面原因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)價格從2011年(nian)起開始低于(yu)石(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),僅約(yue)為大(da)(da)宗(zong)石(shi)油(you)(you)基(ji)(ji)橡(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)為廉價的(de)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),并開始大(da)(da)規模替代石(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)。這(zhe)(zhe)將(jiang)極大(da)(da)拓(tuo)展有(you)機(ji)(ji)硅(gui)(gui)產(chan)(chan)業(ye)的(de)市(shi)場(chang)空間,同(tong)時將(jiang)帶(dai)動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂等(deng)其他有(you)機(ji)(ji)硅(gui)(gui)產(chan)(chan)品(pin)的(de)消費(fei)(fei)。