硅橡膠是指主(zhu)鏈(lian)由(you)硅和氧(yang)原子交替構成(cheng)(cheng),硅原子上通常連有(you)(you)兩(liang)個有(you)(you)機基(ji)團的(de)橡(xiang)(xiang)膠(jiao)(jiao)。普通的(de)硅橡(xiang)(xiang)膠(jiao)(jiao)主(zhu)要由(you)含甲(jia)基(ji)和少量乙烯基(ji)的(de)硅氧(yang)鏈(lian)節(jie)組成(cheng)(cheng)。苯基(ji)的(de)引入可(ke)提(ti)高硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)耐(nai)(nai)高、低溫(wen)性(xing)能(neng)(neng)(neng),三氟丙基(ji)及氰基(ji)的(de)引入則可(ke)提(ti)高硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)能(neng)(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)耐(nai)(nai)低溫(wen)性(xing)能(neng)(neng)(neng)良好(hao),一般在(zai)-55℃下仍能(neng)(neng)(neng)工作。引入苯基(ji)后,可(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)耐(nai)(nai)熱(re)性(xing)能(neng)(neng)(neng)也(ye)很突(tu)(tu)出,在(zai)180℃下可(ke)長(chang)期工作,稍高于200℃也(ye)能(neng)(neng)(neng)承受數周或更長(chang)時間仍有(you)(you)彈性(xing),瞬(shun)時可(ke)耐(nai)(nai)300℃以上的(de)高溫(wen)。硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)透(tou)(tou)氣性(xing)好(hao),氧(yang)氣透(tou)(tou)過(guo)率在(zai)合成(cheng)(cheng)聚合物中(zhong)是較高的(de)。此(ci)外,硅橡(xiang)(xiang)膠(jiao)(jiao)還具有(you)(you)生(sheng)理惰性(xing)、不會(hui)導(dao)致凝血的(de)突(tu)(tu)出特性(xing),因此(ci)在(zai)醫用(yong)領(ling)域應用(yong)廣泛。
主(zhu)要品種(zhong)
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)分(fen)(fen)類的(de)(de)方(fang)法很多,通(tong)常按固(gu)(gu)化(hua)前的(de)(de)形(xing)態分(fen)(fen)為(wei)固(gu)(gu)體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)和(he)液體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按硫化(hua)溫(wen)度分(fen)(fen)為(wei)室(shi)溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),高溫(wen)硫化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按所用單(dan)體的(de)(de)不同,可(ke)(ke)分(fen)(fen)為(wei)甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)等(deng);按性能和(he)用途的(de)(de)不同又(you)可(ke)(ke)分(fen)(fen)為(wei)通(tong)用型(xing)、超(chao)耐(nai)低溫(wen)型(xing)、超(chao)耐(nai)高溫(wen)型(xing)、高強力型(xing)、耐(nai)油型(xing)、醫用型(xing)等(deng)等(deng)。
發(fa)展史
硅橡(xiang)(xiang)膠(jiao)(jiao)早期是由美國(guo)以三氯(lv)化(hua)鐵為(wei)催化(hua)劑合成(cheng)的(de)。1945年(nian),硅橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品問世。1948年(nian),采用(yong)高(gao)比(bi)表面積的(de)氣相法白(bai)炭黑補強的(de)硅橡(xiang)(xiang)膠(jiao)(jiao)研(yan)(yan)制(zhi)成(cheng)功,使(shi)硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)性能躍升(sheng)到實用(yong)階段,奠定了現代硅橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)技術的(de)基礎。從二(er)甲基二(er)氯(lv)硅烷合成(cheng)開始生產(chan)硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)家有(you)美國(guo)。俄羅(luo)斯、德國(guo)、日(ri)本、韓(han)國(guo)和中(zhong)(zhong)國(guo)等。中(zhong)(zhong)國(guo)硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)化(hua)研(yan)(yan)究(jiu)始于1957年(nian),多(duo)家研(yan)(yan)究(jiu)所和企(qi)業(ye)陸續(xu)開發出各種硅橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底,中(zhong)(zhong)國(guo)硅橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)能力(li)為(wei)135千(qian)噸(dun)(dun),其中(zhong)(zhong)高(gao)溫膠(jiao)(jiao)100千(qian)噸(dun)(dun)。
高溫硫(liu)化硅橡膠
高(gao)溫硫化(hua)(hua)(hua)硅橡膠是(shi)(shi)指聚(ju)硅氧(yang)烷(wan)變成(cheng)(cheng)彈性(xing)(xing)體的(de)(de)(de)過程是(shi)(shi)經(jing)過高(gao)溫(110-170℃)硫化(hua)(hua)(hua)成(cheng)(cheng)型的(de)(de)(de)。它(ta)主(zhu)要以高(gao)分子量的(de)(de)(de)聚(ju)甲基乙(yi)烯基硅氧(yang)烷(wan)為生膠,混入補強(qiang)填料(liao)、硫化(hua)(hua)(hua)劑(ji)等,在加熱(re)加壓下硫化(hua)(hua)(hua)成(cheng)(cheng)彈性(xing)(xing)體。硅橡膠的(de)(de)(de)補強(qiang)主(zhu)要是(shi)(shi)各種類型的(de)(de)(de)白炭黑,可使硫化(hua)(hua)(hua)膠的(de)(de)(de)強(qiang)度增加數十倍(bei)。有時為了降低成(cheng)(cheng)本或改善膠料(liao)性(xing)(xing)能及賦(fu)予硫化(hua)(hua)(hua)膠各種特殊的(de)(de)(de)性(xing)(xing)能,也加入相應(ying)的(de)(de)(de)各種添加劑(ji)。硫化(hua)(hua)(hua)劑(ji)是(shi)(shi)各種有機過氧(yang)化(hua)(hua)(hua)物或加成(cheng)(cheng)反應(ying)催化(hua)(hua)(hua)劑(ji)。
加工成型方法如(ru)圖所示。一次(ci)硫(liu)(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是進(jin)行(xing)高分(fen)子鏈的(de)(de)交聯反應;二(er)次(ci)硫(liu)(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是進(jin)行(xing)補充交聯、驅除(chu)硫(liu)(liu)化(hua)(hua)劑分(fen)解產物和(he)其(qi)他揮發(fa)性(xing)化(hua)(hua)合(he)物以穩定(ding)硫(liu)(liu)化(hua)(hua)膠的(de)(de)各項性(xing)能(neng)。常(chang)用的(de)(de)設備(bei)有開放式煉膠機(ji)、捏合(he)機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特征是高(gao)溫(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)常(chang)(chang)溫(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強(qiang)度(du)(du)僅是天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些(xie)合(he)成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在200℃以(yi)上(shang)的(de)(de)(de)高(gao)溫(wen)環境下(xia)(xia),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一定(ding)的(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度(du)(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明顯變化(hua)。(2)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)度(du)(du)一般為-70~-50℃,特殊配方可達(da)-100℃,表明其低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對航空(kong)、宇航工業(ye)的(de)(de)(de)意(yi)義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對氧、臭氧及(ji)紫外線等(deng)(deng)十分穩(wen)定(ding),在不(bu)加任何添加劑的(de)(de)(de)情況(kuang)下(xia)(xia),就具(ju)(ju)(ju)有優良的(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有優異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常(chang)(chang)好。(5)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)下(xia)(xia)的(de)(de)(de)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高(gao)溫(wen)和(he)(he)-50℃的(de)(de)(de)低(di)溫(wen)下(xia)(xia),其物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及(ji)化(hua)學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)(ju)有中等(deng)(deng)的(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室(shi)溫(wen)下(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對空(kong)氣(qi)(qi)、氮、氧、二氧化(hua)碳等(deng)(deng)氣(qi)(qi)體的(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅(xiu),與人體組織不(bu)粘連,具(ju)(ju)(ju)有抗(kang)凝血作用,對肌體組織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少(shao)。特別適合(he)作為醫(yi)用材料。
硅橡(xiang)膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)工業(ye)(ye)協會(hui)統計(ji),2012年(nian),汽(qi)(qi)(qi)車(che)產銷(xiao)分別達(da)到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同比分別增(zeng)(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)工業(ye)(ye)硅(gui)(gui)橡膠的(de)用(yong)(yong)量(liang)約達(da)2.0萬(wan)(wan)t。根(gen)據觀研(yan)天下的(de)新研(yan)究,增(zeng)(zeng)加有(you)機(ji)硅(gui)(gui)材(cai)料在(zai)汽(qi)(qi)(qi)車(che)零部件方(fang)面的(de)用(yong)(yong)量(liang),可(ke)以(yi)大(da)幅度(du)提(ti)高汽(qi)(qi)(qi)車(che)的(de)安全(quan)性能,因此,汽(qi)(qi)(qi)車(che)產量(liang)和(he)單車(che)用(yong)(yong)量(liang)水平的(de)提(ti)高都將推動汽(qi)(qi)(qi)車(che)工業(ye)(ye)對硅(gui)(gui)橡膠需求(qiu)的(de)增(zeng)(zeng)加。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)的(de)汽(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)車(che)零部件實現自(zi)主(zhu)化(hua),《2012年(nian)度(du)黨(dang)政機(ji)關公(gong)務用(yong)(yong)車(che)選(xuan)用(yong)(yong)車(che)型(xing)目錄(征求(qiu)意見(jian)稿)》為自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)擴大(da)在(zai)政府采購的(de)市(shi)場份額,為改變目前國(guo)內政府采購以(yi)合資品(pin)(pin)(pin)牌(pai)產品(pin)(pin)(pin)為主(zhu)的(de)局面提(ti)供了保障。促進自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)發展,國(guo)產汽(qi)(qi)(qi)車(che)業(ye)(ye)的(de)繁(fan)榮將為汽(qi)(qi)(qi)車(che)膠的(de)應用(yong)(yong)提(ti)供有(you)力保障。預測未來3年(nian),我國(guo)室溫硫化(hua)硅(gui)(gui)橡膠在(zai)汽(qi)(qi)(qi)車(che)行業(ye)(ye)將以(yi)年(nian)均20%增(zeng)(zeng)長(chang)。
此外(wai),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要的(de)(de)非石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao),約(yue)占非石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)量的(de)(de)98%。但(dan)因為(wei)(wei)石(shi)(shi)油(you)(you)價格(ge)(ge)的(de)(de)大(da)(da)(da)幅上漲,同(tong)時我國(guo)在硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)關(guan)鍵原(yuan)料有(you)機(ji)硅(gui)(gui)單體的(de)(de)生產(chan)技術方(fang)面(mian)取得突(tu)破,有(you)機(ji)硅(gui)(gui)單體的(de)(de)生產(chan)技術在2005年(nian)前被幾家跨(kua)國(guo)公(gong)司壟斷,但(dan)目前我國(guo)已發展成(cheng)為(wei)(wei)全球有(you)機(ji)硅(gui)(gui)單體第1大(da)(da)(da)國(guo),這2個(ge)方(fang)面(mian)原(yuan)因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)價格(ge)(ge)從2011年(nian)起開始(shi)低于石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao),僅(jin)約(yue)為(wei)(wei)大(da)(da)(da)宗(zong)石(shi)(shi)油(you)(you)基(ji)(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為(wei)(wei)廉價的(de)(de)合成(cheng)橡(xiang)膠(jiao)(jiao),并開始(shi)大(da)(da)(da)規模替(ti)代(dai)石(shi)(shi)油(you)(you)基(ji)(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)。這將極大(da)(da)(da)拓展有(you)機(ji)硅(gui)(gui)產(chan)業的(de)(de)市場空(kong)間,同(tong)時將帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷(wan)偶聯劑(ji)和硅(gui)(gui)樹脂等其(qi)他有(you)機(ji)硅(gui)(gui)產(chan)品的(de)(de)消費(fei)。