硅橡膠是指主鏈由硅(gui)(gui)和(he)氧(yang)原子(zi)交替(ti)構(gou)成,硅(gui)(gui)原子(zi)上通常連有(you)兩個有(you)機基(ji)團(tuan)的(de)(de)橡(xiang)(xiang)(xiang)膠。普通的(de)(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠主要由含甲基(ji)和(he)少量乙烯基(ji)的(de)(de)硅(gui)(gui)氧(yang)鏈節組成。苯(ben)基(ji)的(de)(de)引入可(ke)提高(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)高(gao)、低溫性(xing)(xing)(xing)能(neng)(neng),三(san)氟丙基(ji)及氰基(ji)的(de)(de)引入則(ze)可(ke)提高(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)溫及耐(nai)(nai)油性(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠耐(nai)(nai)低溫性(xing)(xing)(xing)能(neng)(neng)良好,一(yi)般在(zai)(zai)-55℃下仍能(neng)(neng)工作(zuo)。引入苯(ben)基(ji)后(hou),可(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)熱(re)性(xing)(xing)(xing)能(neng)(neng)也很突出,在(zai)(zai)180℃下可(ke)長(chang)期工作(zuo),稍(shao)高(gao)于200℃也能(neng)(neng)承(cheng)受數周(zhou)或更長(chang)時間仍有(you)彈性(xing)(xing)(xing),瞬(shun)時可(ke)耐(nai)(nai)300℃以上的(de)(de)高(gao)溫。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)透氣性(xing)(xing)(xing)好,氧(yang)氣透過率在(zai)(zai)合成聚(ju)合物中是較高(gao)的(de)(de)。此(ci)外(wai),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠還具(ju)有(you)生(sheng)理惰(duo)性(xing)(xing)(xing)、不會導致(zhi)凝血的(de)(de)突出特(te)性(xing)(xing)(xing),因此(ci)在(zai)(zai)醫(yi)用領域應用廣泛。
主要品種
硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)分(fen)(fen)類的(de)(de)方法很多,通常按固化(hua)前的(de)(de)形態分(fen)(fen)為(wei)固體硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)和液體硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao);按硫化(hua)溫(wen)(wen)度(du)分(fen)(fen)為(wei)室溫(wen)(wen)硫化(hua)硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao),高(gao)溫(wen)(wen)硫化(hua)硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao);按所用單體的(de)(de)不同(tong),可分(fen)(fen)為(wei)甲(jia)基乙烯(xi)基硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao),甲(jia)基苯基乙烯(xi)基硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui)(gui)(gui)(gui)(gui),腈硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)等;按性能和用途的(de)(de)不同(tong)又可分(fen)(fen)為(wei)通用型(xing)(xing)(xing)、超耐(nai)低溫(wen)(wen)型(xing)(xing)(xing)、超耐(nai)高(gao)溫(wen)(wen)型(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)、耐(nai)油型(xing)(xing)(xing)、醫用型(xing)(xing)(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由美(mei)國(guo)(guo)(guo)以(yi)三(san)氯(lv)化(hua)(hua)鐵(tie)為催化(hua)(hua)劑(ji)合成(cheng)的(de)(de)。1945年,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品問世(shi)。1948年,采用(yong)高(gao)比表(biao)面積的(de)(de)氣相法白炭黑補強的(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)性能躍升到實(shi)用(yong)階(jie)段,奠定了現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產技(ji)術的(de)(de)基(ji)礎。從二(er)甲基(ji)二(er)氯(lv)硅(gui)烷合成(cheng)開始(shi)(shi)生(sheng)產硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)國(guo)(guo)(guo)家(jia)有美(mei)國(guo)(guo)(guo)。俄(e)羅斯、德(de)國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)(zhong)國(guo)(guo)(guo)等(deng)。中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)工業化(hua)(hua)研(yan)究(jiu)始(shi)(shi)于(yu)1957年,多(duo)家(jia)研(yan)究(jiu)所和企(qi)業陸(lu)續開發出(chu)各種硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年底,中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產能力(li)為135千(qian)噸(dun)(dun),其中(zhong)(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千(qian)噸(dun)(dun)。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)(hua)硅橡(xiang)(xiang)膠(jiao)(jiao)是(shi)指聚(ju)硅氧烷變成(cheng)(cheng)彈(dan)性體(ti)的過程是(shi)經過高溫(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)型(xing)的。它主(zhu)要以高分子量的聚(ju)甲基(ji)乙烯基(ji)硅氧烷為生膠(jiao)(jiao),混(hun)入(ru)補(bu)強填料、硫(liu)(liu)化(hua)(hua)(hua)劑等(deng),在加(jia)(jia)熱加(jia)(jia)壓(ya)下(xia)硫(liu)(liu)化(hua)(hua)(hua)成(cheng)(cheng)彈(dan)性體(ti)。硅橡(xiang)(xiang)膠(jiao)(jiao)的補(bu)強主(zhu)要是(shi)各種類型(xing)的白炭黑,可(ke)使硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的強度增(zeng)加(jia)(jia)數十(shi)倍。有(you)時為了降低成(cheng)(cheng)本或(huo)改(gai)善膠(jiao)(jiao)料性能(neng)(neng)及賦予硫(liu)(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各種特殊的性能(neng)(neng),也加(jia)(jia)入(ru)相(xiang)應的各種添加(jia)(jia)劑。硫(liu)(liu)化(hua)(hua)(hua)劑是(shi)各種有(you)機(ji)過氧化(hua)(hua)(hua)物或(huo)加(jia)(jia)成(cheng)(cheng)反應催化(hua)(hua)(hua)劑。
加工成型(xing)方法如(ru)圖所示。一次(ci)(ci)硫(liu)化(hua)(hua)(hua)的(de)(de)目的(de)(de)是進行高(gao)分(fen)子鏈(lian)的(de)(de)交聯(lian)反(fan)應;二次(ci)(ci)硫(liu)化(hua)(hua)(hua)的(de)(de)目的(de)(de)是進行補充交聯(lian)、驅除硫(liu)化(hua)(hua)(hua)劑分(fen)解產物和其他揮發性(xing)化(hua)(hua)(hua)合(he)(he)物以穩定硫(liu)化(hua)(hua)(hua)膠的(de)(de)各項性(xing)能。常(chang)用的(de)(de)設(she)備有開放(fang)式煉(lian)膠機(ji)、捏合(he)(he)機(ji)及真空密(mi)煉(lian)機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特征是高(gao)溫(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅是天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)一半,但(dan)在200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)環境下(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)保持(chi)一定的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)(wu)明(ming)(ming)顯變化(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化(hua)溫(wen)(wen)度(du)一般為(wei)-70~-50℃,特殊配方(fang)可達-100℃,表(biao)(biao)明(ming)(ming)其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對(dui)(dui)航空、宇航工業的(de)(de)(de)(de)(de)意(yi)義(yi)重(zhong)大。(3)耐候(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)(dui)氧、臭(chou)氧及紫外線等十分穩(wen)定,在不(bu)加任(ren)何添加劑(ji)的(de)(de)(de)(de)(de)情況下(xia)(xia),就具(ju)有(you)優良的(de)(de)(de)(de)(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)優異的(de)(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常好。(5)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)下(xia)(xia)的(de)(de)(de)(de)(de)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比(bi)(bi)通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)和(he)-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)下(xia)(xia),其物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐油及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)中等的(de)(de)(de)(de)(de)耐油、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣、氮、氧、二氧化(hua)碳(tan)等氣體的(de)(de)(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)(bi)天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人體組織不(bu)粘連,具(ju)有(you)抗(kang)凝血作(zuo)用,對(dui)(dui)肌體組織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別適合作(zuo)為(wei)醫用材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)工(gong)(gong)業協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)產(chan)(chan)銷分別(bie)達到(dao)1927.18萬(wan)輛和1930.64萬(wan)輛,同比分別(bie)增(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)(qi)車(che)工(gong)(gong)業硅橡膠(jiao)(jiao)的(de)用(yong)(yong)量(liang)(liang)約達2.0萬(wan)t。根(gen)據觀研(yan)天下的(de)新研(yan)究(jiu),增(zeng)加有(you)機硅材料在汽(qi)(qi)(qi)車(che)零部(bu)件方面的(de)用(yong)(yong)量(liang)(liang),可以大(da)幅度(du)提(ti)(ti)高汽(qi)(qi)(qi)車(che)的(de)安全(quan)性能(neng),因此(ci),汽(qi)(qi)(qi)車(che)產(chan)(chan)量(liang)(liang)和單(dan)車(che)用(yong)(yong)量(liang)(liang)水平的(de)提(ti)(ti)高都(dou)將(jiang)推動(dong)汽(qi)(qi)(qi)車(che)工(gong)(gong)業對硅橡膠(jiao)(jiao)需求的(de)增(zeng)加。國家鼓勵自(zi)主品牌的(de)汽(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)車(che)零部(bu)件實現自(zi)主化(hua)(hua),《2012年(nian)度(du)黨政(zheng)機關公務用(yong)(yong)車(che)選用(yong)(yong)車(che)型目錄(征求意見稿(gao))》為(wei)(wei)自(zi)主品牌擴(kuo)大(da)在政(zheng)府采購的(de)市場份(fen)額,為(wei)(wei)改變目前國內政(zheng)府采購以合資(zi)品牌產(chan)(chan)品為(wei)(wei)主的(de)局(ju)面提(ti)(ti)供了保障(zhang)。促進自(zi)主品牌發展,國產(chan)(chan)汽(qi)(qi)(qi)車(che)業的(de)繁(fan)榮將(jiang)為(wei)(wei)汽(qi)(qi)(qi)車(che)膠(jiao)(jiao)的(de)應用(yong)(yong)提(ti)(ti)供有(you)力保障(zhang)。預(yu)測未來3年(nian),我國室溫硫化(hua)(hua)硅橡膠(jiao)(jiao)在汽(qi)(qi)(qi)車(che)行業將(jiang)以年(nian)均20%增(zeng)長(chang)。
此(ci)外,硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)是重(zhong)要的非(fei)石(shi)(shi)油(you)基合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),約占非(fei)石(shi)(shi)油(you)基合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)消(xiao)(xiao)費量的98%。但因為石(shi)(shi)油(you)價格(ge)的大幅上漲,同時我國在硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)單體的生產技(ji)術方面取得突破,有(you)(you)機(ji)硅(gui)單體的生產技(ji)術在2005年前被幾家跨國公司壟斷,但目前我國已發(fa)展成(cheng)為全球有(you)(you)機(ji)硅(gui)單體第1大國,這2個方面原因使硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的價格(ge)從2011年起(qi)開(kai)始低于石(shi)(shi)油(you)基合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),僅約為大宗石(shi)(shi)油(you)基橡(xiang)(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)為廉價的合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),并(bing)開(kai)始大規(gui)模替代(dai)石(shi)(shi)油(you)基合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)。這將極大拓展有(you)(you)機(ji)硅(gui)產業(ye)的市場(chang)空間,同時將帶動硅(gui)油(you)、硅(gui)烷(wan)偶聯劑(ji)和硅(gui)樹脂等其(qi)他有(you)(you)機(ji)硅(gui)產品的消(xiao)(xiao)費。