硅橡膠是指主鏈由硅(gui)和氧原子交替構成(cheng)(cheng)(cheng),硅(gui)原子上(shang)通常連有(you)兩(liang)個有(you)機基(ji)(ji)團(tuan)的(de)橡膠(jiao)(jiao)。普通的(de)硅(gui)橡膠(jiao)(jiao)主要(yao)由含甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)硅(gui)氧鏈節組成(cheng)(cheng)(cheng)。苯基(ji)(ji)的(de)引入(ru)(ru)可(ke)(ke)提高硅(gui)橡膠(jiao)(jiao)的(de)耐(nai)高、低溫性(xing)(xing)能,三氟丙(bing)基(ji)(ji)及氰(qing)基(ji)(ji)的(de)引入(ru)(ru)則(ze)可(ke)(ke)提高硅(gui)橡膠(jiao)(jiao)的(de)耐(nai)溫及耐(nai)油性(xing)(xing)能。硅(gui)橡膠(jiao)(jiao)耐(nai)低溫性(xing)(xing)能良好(hao),一般在-55℃下(xia)(xia)仍能工作(zuo)。引入(ru)(ru)苯基(ji)(ji)后(hou),可(ke)(ke)達-73℃。硅(gui)橡膠(jiao)(jiao)的(de)耐(nai)熱性(xing)(xing)能也很(hen)突(tu)出,在180℃下(xia)(xia)可(ke)(ke)長期(qi)工作(zuo),稍高于200℃也能承受數(shu)周或更長時(shi)(shi)間仍有(you)彈(dan)性(xing)(xing),瞬時(shi)(shi)可(ke)(ke)耐(nai)300℃以上(shang)的(de)高溫。硅(gui)橡膠(jiao)(jiao)的(de)透(tou)氣(qi)(qi)性(xing)(xing)好(hao),氧氣(qi)(qi)透(tou)過率在合成(cheng)(cheng)(cheng)聚合物中是較高的(de)。此外,硅(gui)橡膠(jiao)(jiao)還具有(you)生(sheng)理惰性(xing)(xing)、不會導致凝血(xue)的(de)突(tu)出特性(xing)(xing),因此在醫(yi)用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠分(fen)(fen)類的(de)方法(fa)很多(duo),通常按(an)固化(hua)(hua)(hua)前的(de)形態分(fen)(fen)為(wei)固體(ti)硅(gui)(gui)(gui)橡(xiang)膠和液(ye)體(ti)硅(gui)(gui)(gui)橡(xiang)膠;按(an)硫(liu)化(hua)(hua)(hua)溫度分(fen)(fen)為(wei)室溫硫(liu)化(hua)(hua)(hua)硅(gui)(gui)(gui)橡(xiang)膠,高(gao)溫硫(liu)化(hua)(hua)(hua)硅(gui)(gui)(gui)橡(xiang)膠;按(an)所用單體(ti)的(de)不同,可(ke)分(fen)(fen)為(wei)甲(jia)基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠,甲(jia)基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)(gui)橡(xiang)膠、氟(fu)硅(gui)(gui)(gui),腈(jing)硅(gui)(gui)(gui)橡(xiang)膠等;按(an)性能(neng)和用途的(de)不同又(you)可(ke)分(fen)(fen)為(wei)通用型(xing)(xing)、超耐低(di)溫型(xing)(xing)、超耐高(gao)溫型(xing)(xing)、高(gao)強力型(xing)(xing)、耐油型(xing)(xing)、醫用型(xing)(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期是(shi)由美(mei)國以三(san)氯(lv)化(hua)鐵為催(cui)化(hua)劑合成的(de)。1945年(nian)(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)(chan)品問世(shi)。1948年(nian)(nian),采用高比表(biao)面積的(de)氣相法白炭黑補強的(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)研(yan)制成功,使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)性能躍升到(dao)實用階(jie)段,奠定了現代(dai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)(chan)技術的(de)基礎。從二(er)甲基二(er)氯(lv)硅(gui)烷合成開(kai)(kai)始生(sheng)產(chan)(chan)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)國家有美(mei)國。俄羅斯、德國、日本、韓國和(he)(he)中(zhong)(zhong)國等。中(zhong)(zhong)國硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)化(hua)研(yan)究始于1957年(nian)(nian),多家研(yan)究所和(he)(he)企業(ye)陸續開(kai)(kai)發出(chu)各種硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)(nian)底(di),中(zhong)(zhong)國硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)(chan)能力為135千噸(dun),其中(zhong)(zhong)高溫膠(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)化(hua)硅(gui)橡膠(jiao)(jiao)是(shi)(shi)指(zhi)聚(ju)硅(gui)氧(yang)烷(wan)變成(cheng)(cheng)彈性(xing)(xing)體的(de)(de)過程是(shi)(shi)經(jing)過高溫(110-170℃)硫(liu)化(hua)成(cheng)(cheng)型(xing)的(de)(de)。它主要(yao)以高分子量(liang)的(de)(de)聚(ju)甲基(ji)乙烯基(ji)硅(gui)氧(yang)烷(wan)為(wei)生膠(jiao)(jiao),混(hun)入補強填料、硫(liu)化(hua)劑(ji)等,在加(jia)(jia)熱(re)加(jia)(jia)壓下硫(liu)化(hua)成(cheng)(cheng)彈性(xing)(xing)體。硅(gui)橡膠(jiao)(jiao)的(de)(de)補強主要(yao)是(shi)(shi)各(ge)種(zhong)類(lei)型(xing)的(de)(de)白炭黑,可使(shi)硫(liu)化(hua)膠(jiao)(jiao)的(de)(de)強度增(zeng)加(jia)(jia)數十倍。有(you)(you)時(shi)為(wei)了降(jiang)低成(cheng)(cheng)本或(huo)改(gai)善膠(jiao)(jiao)料性(xing)(xing)能(neng)及賦予硫(liu)化(hua)膠(jiao)(jiao)各(ge)種(zhong)特殊的(de)(de)性(xing)(xing)能(neng),也(ye)加(jia)(jia)入相應的(de)(de)各(ge)種(zhong)添加(jia)(jia)劑(ji)。硫(liu)化(hua)劑(ji)是(shi)(shi)各(ge)種(zhong)有(you)(you)機過氧(yang)化(hua)物或(huo)加(jia)(jia)成(cheng)(cheng)反應催(cui)化(hua)劑(ji)。
加工(gong)成型(xing)方法如(ru)圖所示。一次(ci)硫化(hua)的(de)(de)目的(de)(de)是進行高分子鏈的(de)(de)交(jiao)聯反(fan)應(ying);二次(ci)硫化(hua)的(de)(de)目的(de)(de)是進行補充交(jiao)聯、驅(qu)除(chu)硫化(hua)劑分解產物和其他(ta)揮發(fa)性化(hua)合(he)物以穩定(ding)硫化(hua)膠的(de)(de)各項性能(neng)。常用的(de)(de)設備(bei)有開(kai)放式(shi)煉膠機、捏合(he)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)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯著的(de)(de)(de)特征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)強(qiang)度僅是(shi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某些(xie)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)一(yi)半,但(dan)在(zai)(zai)200℃以上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia)(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍(reng)能(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)(wu)(wu)明顯變化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度一(yi)般為-70~-50℃,特殊配方可(ke)達-100℃,表明其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)異。這對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭(chou)氧(yang)及(ji)(ji)紫外線等(deng)十分穩定(ding),在(zai)(zai)不加任(ren)何添加劑的(de)(de)(de)情況下(xia)(xia),就具(ju)(ju)有(you)(you)(you)優(you)(you)良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)(ju)有(you)(you)(you)優(you)(you)異的(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常(chang)溫(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比(bi)通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)在(zai)(zai)150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下(xia)(xia),其物理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)于通(tong)用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)油及(ji)(ji)化(hua)學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)(ju)有(you)(you)(you)中等(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對(dui)空氣(qi)、氮、氧(yang)、二氧(yang)化(hua)碳等(deng)氣(qi)體的(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)出(chu)30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)(wu)(wu)毒,無(wu)(wu)(wu)味,無(wu)(wu)(wu)嗅(xiu),與人體組(zu)織不粘連,具(ju)(ju)有(you)(you)(you)抗凝血(xue)作(zuo)用(yong)(yong),對(dui)肌體組(zu)織的(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別適(shi)合(he)作(zuo)為醫用(yong)(yong)材料。
硅橡膠的用量
據(ju)中(zhong)國汽(qi)(qi)車工業(ye)(ye)協會(hui)統計(ji),2012年(nian),汽(qi)(qi)車產銷(xiao)分別達(da)到1927.18萬輛和(he)1930.64萬輛,同比分別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)車工業(ye)(ye)硅(gui)橡(xiang)膠的用(yong)量約達(da)2.0萬t。根據(ju)觀研天下(xia)的新(xin)研究,增(zeng)加有機硅(gui)材料在(zai)汽(qi)(qi)車零(ling)部(bu)件(jian)方面的用(yong)量,可以(yi)大幅度提(ti)高(gao)汽(qi)(qi)車的安全性(xing)能,因此,汽(qi)(qi)車產量和(he)單車用(yong)量水平(ping)的提(ti)高(gao)都將推(tui)動汽(qi)(qi)車工業(ye)(ye)對硅(gui)橡(xiang)膠需求的增(zeng)加。國家鼓(gu)勵自(zi)主品牌的汽(qi)(qi)車發展(zhan),關(guan)鍵(jian)汽(qi)(qi)車零(ling)部(bu)件(jian)實現自(zi)主化,《2012年(nian)度黨政(zheng)機關(guan)公務用(yong)車選用(yong)車型目(mu)錄(征求意見(jian)稿)》為自(zi)主品牌擴大在(zai)政(zheng)府采購的市場份額,為改變目(mu)前(qian)國內政(zheng)府采購以(yi)合資品牌產品為主的局面提(ti)供(gong)了保(bao)障。促進自(zi)主品牌發展(zhan),國產汽(qi)(qi)車業(ye)(ye)的繁榮將為汽(qi)(qi)車膠的應用(yong)提(ti)供(gong)有力保(bao)障。預測未來3年(nian),我國室(shi)溫(wen)硫化硅(gui)橡(xiang)膠在(zai)汽(qi)(qi)車行業(ye)(ye)將以(yi)年(nian)均20%增(zeng)長(chang)。
此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重要的(de)(de)非(fei)石(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非(fei)石(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消費量(liang)的(de)(de)98%。但因為(wei)石(shi)油(you)(you)價格(ge)的(de)(de)大(da)(da)幅上漲(zhang),同時(shi)我國在硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)關鍵原(yuan)料有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)單體的(de)(de)生產技術方(fang)面取得突破,有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)單體的(de)(de)生產技術在2005年前(qian)(qian)被幾(ji)家(jia)跨(kua)國公司壟斷,但目前(qian)(qian)我國已發展成(cheng)(cheng)為(wei)全球有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)單體第(di)1大(da)(da)國,這2個方(fang)面原(yuan)因使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)價格(ge)從2011年起(qi)開始低于(yu)石(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅(jin)約為(wei)大(da)(da)宗石(shi)油(you)(you)基橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉(lian)價的(de)(de)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開始大(da)(da)規模替代石(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)(da)拓展有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)產業的(de)(de)市(shi)場空間,同時(shi)將(jiang)帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯(lian)劑(ji)和(he)硅(gui)(gui)樹脂(zhi)等(deng)其他有(you)(you)機(ji)(ji)(ji)硅(gui)(gui)產品的(de)(de)消費。