
硅橡膠是指主鏈由(you)硅(gui)(gui)(gui)和(he)氧(yang)(yang)原子交(jiao)替構成,硅(gui)(gui)(gui)原子上(shang)通(tong)常連(lian)有兩個有機基(ji)(ji)團的橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。普(pu)通(tong)的硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)主要(yao)由(you)含甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的硅(gui)(gui)(gui)氧(yang)(yang)鏈節組成。苯基(ji)(ji)的引(yin)(yin)入(ru)可(ke)提(ti)高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐高(gao)(gao)、低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng),三(san)氟丙基(ji)(ji)及氰基(ji)(ji)的引(yin)(yin)入(ru)則可(ke)提(ti)高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐溫(wen)及耐油性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng)良(liang)好,一(yi)般(ban)在-55℃下仍能(neng)(neng)(neng)工作。引(yin)(yin)入(ru)苯基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的耐熱性(xing)(xing)能(neng)(neng)(neng)也很(hen)突(tu)出(chu),在180℃下可(ke)長期工作,稍高(gao)(gao)于200℃也能(neng)(neng)(neng)承受數周或更(geng)長時間(jian)仍有彈性(xing)(xing),瞬時可(ke)耐300℃以(yi)上(shang)的高(gao)(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的透氣性(xing)(xing)好,氧(yang)(yang)氣透過(guo)率在合成聚合物中是較高(gao)(gao)的。此(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有生理惰性(xing)(xing)、不會導(dao)致凝血(xue)的突(tu)出(chu)特(te)性(xing)(xing),因此(ci)在醫用領域應用廣泛。
主要品種
硅(gui)橡膠(jiao)分(fen)(fen)類的方法(fa)很多(duo),通(tong)常按固化(hua)(hua)前的形態分(fen)(fen)為固體硅(gui)橡膠(jiao)和液體硅(gui)橡膠(jiao);按硫化(hua)(hua)溫(wen)(wen)度(du)分(fen)(fen)為室(shi)溫(wen)(wen)硫化(hua)(hua)硅(gui)橡膠(jiao),高(gao)溫(wen)(wen)硫化(hua)(hua)硅(gui)橡膠(jiao);按所用單(dan)體的不(bu)同(tong),可分(fen)(fen)為甲基乙(yi)烯(xi)基硅(gui)橡膠(jiao),甲基苯基乙(yi)烯(xi)基硅(gui)橡膠(jiao)、氟硅(gui),腈硅(gui)橡膠(jiao)等;按性能(neng)和用途的不(bu)同(tong)又可分(fen)(fen)為通(tong)用型(xing)(xing)、超耐低(di)溫(wen)(wen)型(xing)(xing)、超耐高(gao)溫(wen)(wen)型(xing)(xing)、高(gao)強力(li)型(xing)(xing)、耐油(you)型(xing)(xing)、醫(yi)用型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期是(shi)由(you)美國(guo)以三氯化(hua)鐵為催化(hua)劑合成的。1945年(nian),硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品問(wen)世(shi)。1948年(nian),采(cai)用(yong)高(gao)比表面積的氣相法白(bai)炭黑補強(qiang)的硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)研(yan)制成功,使(shi)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的性能(neng)躍升到(dao)實用(yong)階(jie)段,奠定了現代(dai)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)技術的基礎。從二(er)甲基二(er)氯硅(gui)(gui)(gui)(gui)烷合成開始(shi)生產(chan)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的國(guo)家有美國(guo)。俄羅(luo)斯、德國(guo)、日本、韓(han)國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的工(gong)業化(hua)研(yan)究始(shi)于1957年(nian),多家研(yan)究所和企(qi)業陸續開發(fa)出各種(zhong)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產(chan)能(neng)力(li)為135千噸,其中(zhong)高(gao)溫膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)化(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao)是(shi)指聚(ju)硅(gui)氧(yang)烷變(bian)成彈性(xing)體的過(guo)程是(shi)經(jing)過(guo)高溫(110-170℃)硫(liu)化(hua)(hua)成型的。它主要(yao)以高分子量的聚(ju)甲(jia)基乙烯基硅(gui)氧(yang)烷為生膠(jiao)(jiao),混(hun)入補強(qiang)填料、硫(liu)化(hua)(hua)劑(ji)等,在加(jia)熱加(jia)壓下硫(liu)化(hua)(hua)成彈性(xing)體。硅(gui)橡(xiang)膠(jiao)(jiao)的補強(qiang)主要(yao)是(shi)各種(zhong)類型的白(bai)炭(tan)黑(hei),可使硫(liu)化(hua)(hua)膠(jiao)(jiao)的強(qiang)度增加(jia)數十倍。有時為了降低(di)成本或(huo)改善膠(jiao)(jiao)料性(xing)能(neng)(neng)及賦予硫(liu)化(hua)(hua)膠(jiao)(jiao)各種(zhong)特(te)殊的性(xing)能(neng)(neng),也加(jia)入相應(ying)的各種(zhong)添(tian)加(jia)劑(ji)。硫(liu)化(hua)(hua)劑(ji)是(shi)各種(zhong)有機過(guo)氧(yang)化(hua)(hua)物或(huo)加(jia)成反應(ying)催化(hua)(hua)劑(ji)。
加工成型方法(fa)如圖所示(shi)。一次硫(liu)(liu)化的(de)目的(de)是進(jin)行高分子(zi)鏈的(de)交聯反應;二次硫(liu)(liu)化的(de)目的(de)是進(jin)行補(bu)充交聯、驅除硫(liu)(liu)化劑分解產物(wu)和其(qi)他揮發(fa)性化合物(wu)以穩定硫(liu)(liu)化膠的(de)各項性能。常用的(de)設備有開放式煉膠機、捏合機及(ji)真空密(mi)煉機。
主要性能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯(xian)著的(de)(de)特征(zheng)是高溫(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)強(qiang)度僅(jin)是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某(mou)些合(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)一(yi)半,但在(zai)(zai)200℃以上的(de)(de)高溫(wen)(wen)(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能保持一(yi)定的(de)(de)柔(rou)韌(ren)性(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)和表面硬度,且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)能無(wu)(wu)(wu)明顯(xian)變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)玻(bo)璃化溫(wen)(wen)(wen)度一(yi)般為(wei)-70~-50℃,特殊配(pei)方(fang)可達(da)-100℃,表明其(qi)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能優異。這對航空、宇航工業的(de)(de)意義重(zhong)大。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵對氧、臭氧及紫外線(xian)等十分穩(wen)定,在(zai)(zai)不加(jia)(jia)任何(he)添加(jia)(jia)劑的(de)(de)情(qing)況下,就具(ju)有(you)優良(liang)的(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)優異的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)能,耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)也非常(chang)好(hao)。(5)物(wu)(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常(chang)溫(wen)(wen)(wen)下的(de)(de)物(wu)(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)能比(bi)(bi)通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差(cha),但在(zai)(zai)150℃的(de)(de)高溫(wen)(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)(wen)下,其(qi)物(wu)(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)能優于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)油及化學(xue)試劑性(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)中等的(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)能。(7)氣(qi)體透(tou)(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)能。室(shi)溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對空氣(qi)、氮、氧、二氧化碳等氣(qi)體的(de)(de)透(tou)(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)比(bi)(bi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高出(chu)30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)(wu)(wu)毒,無(wu)(wu)(wu)味,無(wu)(wu)(wu)嗅,與(yu)人體組織(zhi)不粘連,具(ju)有(you)抗(kang)凝血作用,對肌體組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別適合(he)作為(wei)醫(yi)用材料(liao)。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車工(gong)業協會統計(ji),2012年(nian),汽(qi)(qi)(qi)車產(chan)(chan)(chan)銷分(fen)別達到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同比分(fen)別增長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)車工(gong)業硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)用(yong)量(liang)約達2.0萬(wan)t。根據觀研(yan)天下的(de)(de)(de)新研(yan)究,增加有機硅(gui)材料在(zai)(zai)汽(qi)(qi)(qi)車零部件方面的(de)(de)(de)用(yong)量(liang),可以大(da)(da)幅度(du)提(ti)(ti)高(gao)汽(qi)(qi)(qi)車的(de)(de)(de)安(an)全性能,因此(ci),汽(qi)(qi)(qi)車產(chan)(chan)(chan)量(liang)和(he)單(dan)車用(yong)量(liang)水平的(de)(de)(de)提(ti)(ti)高(gao)都將(jiang)(jiang)推動汽(qi)(qi)(qi)車工(gong)業對硅(gui)橡(xiang)膠(jiao)需求的(de)(de)(de)增加。國家(jia)鼓勵自主品(pin)牌的(de)(de)(de)汽(qi)(qi)(qi)車發展(zhan),關鍵汽(qi)(qi)(qi)車零部件實現自主化,《2012年(nian)度(du)黨政(zheng)機關公務用(yong)車選(xuan)用(yong)車型目錄(征求意見稿)》為(wei)(wei)自主品(pin)牌擴(kuo)大(da)(da)在(zai)(zai)政(zheng)府(fu)采購的(de)(de)(de)市(shi)場(chang)份額,為(wei)(wei)改變目前國內政(zheng)府(fu)采購以合資品(pin)牌產(chan)(chan)(chan)品(pin)為(wei)(wei)主的(de)(de)(de)局面提(ti)(ti)供了保障(zhang)。促進(jin)自主品(pin)牌發展(zhan),國產(chan)(chan)(chan)汽(qi)(qi)(qi)車業的(de)(de)(de)繁榮將(jiang)(jiang)為(wei)(wei)汽(qi)(qi)(qi)車膠(jiao)的(de)(de)(de)應(ying)用(yong)提(ti)(ti)供有力保障(zhang)。預測未來(lai)3年(nian),我國室溫(wen)硫化硅(gui)橡(xiang)膠(jiao)在(zai)(zai)汽(qi)(qi)(qi)車行業將(jiang)(jiang)以年(nian)均(jun)20%增長(chang)。
此外(wai),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是(shi)重(zhong)要的(de)(de)(de)(de)(de)非石(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消(xiao)費量的(de)(de)(de)(de)(de)98%。但因為(wei)(wei)石(shi)油(you)(you)價格的(de)(de)(de)(de)(de)大(da)幅(fu)上漲,同(tong)時我國在(zai)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)關鍵(jian)原(yuan)料有(you)(you)(you)機硅(gui)(gui)單體的(de)(de)(de)(de)(de)生(sheng)產技術方面(mian)取得突破,有(you)(you)(you)機硅(gui)(gui)單體的(de)(de)(de)(de)(de)生(sheng)產技術在(zai)2005年前(qian)被幾家(jia)跨國公司壟斷,但目(mu)前(qian)我國已發展(zhan)成(cheng)(cheng)(cheng)為(wei)(wei)全球(qiu)有(you)(you)(you)機硅(gui)(gui)單體第1大(da)國,這2個(ge)方面(mian)原(yuan)因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)價格從2011年起(qi)開始(shi)低于石(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅(jin)約為(wei)(wei)大(da)宗石(shi)油(you)(you)基(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)(wei)廉價的(de)(de)(de)(de)(de)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開始(shi)大(da)規模替代石(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)拓展(zhan)有(you)(you)(you)機硅(gui)(gui)產業(ye)的(de)(de)(de)(de)(de)市(shi)場空(kong)間,同(tong)時將(jiang)帶(dai)動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷(wan)偶(ou)聯劑(ji)和(he)硅(gui)(gui)樹脂等(deng)其他有(you)(you)(you)機硅(gui)(gui)產品的(de)(de)(de)(de)(de)消(xiao)費。