
硅橡膠是(shi)指主(zhu)鏈由(you)硅和氧原(yuan)子交替構(gou)成(cheng),硅原(yuan)子上(shang)通常連有(you)(you)兩個(ge)有(you)(you)機基(ji)(ji)(ji)團的(de)橡(xiang)(xiang)膠(jiao)。普通的(de)硅橡(xiang)(xiang)膠(jiao)主(zhu)要(yao)由(you)含甲基(ji)(ji)(ji)和少(shao)量乙烯(xi)基(ji)(ji)(ji)的(de)硅氧鏈節組成(cheng)。苯(ben)(ben)基(ji)(ji)(ji)的(de)引(yin)入可(ke)提高(gao)硅橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)高(gao)、低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng),三氟(fu)丙基(ji)(ji)(ji)及氰基(ji)(ji)(ji)的(de)引(yin)入則可(ke)提高(gao)硅橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)耐(nai)(nai)低(di)溫(wen)性(xing)(xing)能(neng)(neng)(neng)良好(hao)(hao),一般(ban)在(zai)-55℃下仍(reng)能(neng)(neng)(neng)工作。引(yin)入苯(ben)(ben)基(ji)(ji)(ji)后,可(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)的(de)耐(nai)(nai)熱性(xing)(xing)能(neng)(neng)(neng)也很突出,在(zai)180℃下可(ke)長(chang)期工作,稍(shao)高(gao)于200℃也能(neng)(neng)(neng)承(cheng)受(shou)數周或更長(chang)時間(jian)仍(reng)有(you)(you)彈性(xing)(xing),瞬(shun)時可(ke)耐(nai)(nai)300℃以上(shang)的(de)高(gao)溫(wen)。硅橡(xiang)(xiang)膠(jiao)的(de)透(tou)氣性(xing)(xing)好(hao)(hao),氧氣透(tou)過率在(zai)合成(cheng)聚合物(wu)中是(shi)較高(gao)的(de)。此(ci)外,硅橡(xiang)(xiang)膠(jiao)還具有(you)(you)生理(li)惰性(xing)(xing)、不(bu)會導(dao)致凝血的(de)突出特(te)性(xing)(xing),因此(ci)在(zai)醫用領域應(ying)用廣泛(fan)。
主要品種
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)分類的方法很(hen)多(duo),通常(chang)按(an)固化前的形態分為固體硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)和液體硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)硫化溫度(du)分為室溫硫化硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),高溫硫化硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)所用(yong)單體的不同(tong)(tong),可分為甲基(ji)乙(yi)烯基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲基(ji)苯(ben)基(ji)乙(yi)烯基(ji)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)等;按(an)性能(neng)和用(yong)途的不同(tong)(tong)又(you)可分為通用(yong)型(xing)、超耐低溫型(xing)、超耐高溫型(xing)、高強(qiang)力型(xing)、耐油型(xing)、醫用(yong)型(xing)等等。
發展史
硅橡(xiang)(xiang)膠(jiao)(jiao)早期是由美(mei)(mei)國(guo)(guo)以三氯化鐵為催化劑合(he)成(cheng)的(de)(de)。1945年(nian),硅橡(xiang)(xiang)膠(jiao)(jiao)產(chan)(chan)品問世。1948年(nian),采用高比表面積的(de)(de)氣相(xiang)法白(bai)炭黑補強的(de)(de)硅橡(xiang)(xiang)膠(jiao)(jiao)研制成(cheng)功,使硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)性(xing)能(neng)躍升到實用階段(duan),奠定了現代硅橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)(chan)技(ji)術的(de)(de)基(ji)礎。從二甲基(ji)二氯硅烷合(he)成(cheng)開始(shi)生(sheng)(sheng)產(chan)(chan)硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)國(guo)(guo)家有美(mei)(mei)國(guo)(guo)。俄(e)羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)(zhong)國(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)工(gong)業化研究始(shi)于(yu)1957年(nian),多家研究所和企業陸續開發(fa)出各(ge)種硅橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底(di),中(zhong)(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)(chan)能(neng)力為135千(qian)噸,其中(zhong)(zhong)高溫膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫(wen)硫(liu)(liu)(liu)化(hua)硅橡膠是(shi)(shi)指聚(ju)硅氧烷(wan)變成(cheng)彈(dan)性體(ti)的(de)(de)(de)(de)過程(cheng)是(shi)(shi)經過高溫(wen)(110-170℃)硫(liu)(liu)(liu)化(hua)成(cheng)型(xing)的(de)(de)(de)(de)。它主(zhu)要以高分子量的(de)(de)(de)(de)聚(ju)甲(jia)基(ji)乙烯基(ji)硅氧烷(wan)為生膠,混入補強填料、硫(liu)(liu)(liu)化(hua)劑等(deng),在加(jia)(jia)熱(re)加(jia)(jia)壓(ya)下(xia)硫(liu)(liu)(liu)化(hua)成(cheng)彈(dan)性體(ti)。硅橡膠的(de)(de)(de)(de)補強主(zhu)要是(shi)(shi)各種(zhong)類型(xing)的(de)(de)(de)(de)白炭黑,可(ke)使(shi)硫(liu)(liu)(liu)化(hua)膠的(de)(de)(de)(de)強度增加(jia)(jia)數十倍。有時為了降低(di)成(cheng)本或(huo)改善膠料性能(neng)及賦予硫(liu)(liu)(liu)化(hua)膠各種(zhong)特殊的(de)(de)(de)(de)性能(neng),也加(jia)(jia)入相(xiang)應的(de)(de)(de)(de)各種(zhong)添加(jia)(jia)劑。硫(liu)(liu)(liu)化(hua)劑是(shi)(shi)各種(zhong)有機過氧化(hua)物或(huo)加(jia)(jia)成(cheng)反(fan)應催化(hua)劑。
加工(gong)成型方法如圖所示。一(yi)次(ci)硫(liu)化的(de)目(mu)(mu)的(de)是進行(xing)(xing)高分(fen)(fen)子(zi)鏈的(de)交聯(lian)反應;二次(ci)硫(liu)化的(de)目(mu)(mu)的(de)是進行(xing)(xing)補(bu)充交聯(lian)、驅(qu)除硫(liu)化劑分(fen)(fen)解產物(wu)和(he)其他(ta)揮發性化合物(wu)以(yi)穩定(ding)硫(liu)化膠(jiao)的(de)各項性能。常用的(de)設備有開放式煉(lian)膠(jiao)機(ji)、捏合機(ji)及真空密煉(lian)機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著(zhu)的(de)(de)特征(zheng)是(shi)高溫(wen)(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)強度(du)僅是(shi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)一(yi)半,但(dan)(dan)在(zai)(zai)200℃以(yi)上的(de)(de)高溫(wen)(wen)(wen)(wen)(wen)環(huan)境下,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能保持一(yi)定的(de)(de)柔(rou)韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能無明顯變化(hua)(hua)。(2)低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)玻璃化(hua)(hua)溫(wen)(wen)(wen)(wen)(wen)度(du)一(yi)般為(wei)-70~-50℃,特殊配方(fang)可達-100℃,表明其低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能優異。這對航空(kong)、宇航工業的(de)(de)意義(yi)重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及(ji)紫外線等十(shi)分穩定,在(zai)(zai)不加任(ren)何(he)添(tian)加劑的(de)(de)情況下,就具(ju)有(you)優良的(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)優異的(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能,耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理機(ji)(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下的(de)(de)物理機(ji)(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能比通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但(dan)(dan)在(zai)(zai)150℃的(de)(de)高溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)(wen)(wen)(wen)下,其物理機(ji)(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能優于(yu)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油及(ji)化(hua)(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)中等的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)能。(7)氣體透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能。室溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對空(kong)氣、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)(hua)碳等氣體的(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高出30-50倍。(8)生理惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無毒,無味,無嗅,與人體組(zu)織(zhi)不粘連,具(ju)有(you)抗凝(ning)血作(zuo)用(yong),對肌體組(zu)織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特別(bie)適合(he)作(zuo)為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)工(gong)業(ye)(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)車(che)產(chan)(chan)(chan)銷分別達到1927.18萬輛和(he)1930.64萬輛,同比(bi)分別增(zeng)(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)車(che)工(gong)業(ye)(ye)硅橡(xiang)(xiang)膠的(de)(de)(de)用(yong)量(liang)約達2.0萬t。根據觀研(yan)天下(xia)的(de)(de)(de)新(xin)研(yan)究,增(zeng)(zeng)加(jia)有機硅材料在(zai)汽(qi)(qi)車(che)零部件方(fang)面的(de)(de)(de)用(yong)量(liang),可以大(da)幅度提(ti)高汽(qi)(qi)車(che)的(de)(de)(de)安(an)全性能,因此,汽(qi)(qi)車(che)產(chan)(chan)(chan)量(liang)和(he)單(dan)車(che)用(yong)量(liang)水(shui)平的(de)(de)(de)提(ti)高都將(jiang)推動(dong)汽(qi)(qi)車(che)工(gong)業(ye)(ye)對硅橡(xiang)(xiang)膠需求(qiu)的(de)(de)(de)增(zeng)(zeng)加(jia)。國(guo)家鼓勵自主(zhu)(zhu)品(pin)(pin)牌的(de)(de)(de)汽(qi)(qi)車(che)發展(zhan),關(guan)(guan)鍵汽(qi)(qi)車(che)零部件實現(xian)自主(zhu)(zhu)化,《2012年(nian)(nian)度黨政(zheng)機關(guan)(guan)公務用(yong)車(che)選用(yong)車(che)型(xing)目(mu)錄(征求(qiu)意見稿)》為(wei)自主(zhu)(zhu)品(pin)(pin)牌擴大(da)在(zai)政(zheng)府(fu)采購(gou)的(de)(de)(de)市場份額,為(wei)改變(bian)目(mu)前國(guo)內政(zheng)府(fu)采購(gou)以合資品(pin)(pin)牌產(chan)(chan)(chan)品(pin)(pin)為(wei)主(zhu)(zhu)的(de)(de)(de)局面提(ti)供(gong)了(le)保障(zhang)。促進(jin)自主(zhu)(zhu)品(pin)(pin)牌發展(zhan),國(guo)產(chan)(chan)(chan)汽(qi)(qi)車(che)業(ye)(ye)的(de)(de)(de)繁(fan)榮將(jiang)為(wei)汽(qi)(qi)車(che)膠的(de)(de)(de)應用(yong)提(ti)供(gong)有力保障(zhang)。預測未來3年(nian)(nian),我國(guo)室溫(wen)硫(liu)化硅橡(xiang)(xiang)膠在(zai)汽(qi)(qi)車(che)行業(ye)(ye)將(jiang)以年(nian)(nian)均20%增(zeng)(zeng)長(chang)。
此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要(yao)的非(fei)石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消(xiao)費(fei)量(liang)的98%。但因(yin)為石(shi)(shi)油(you)價格的大幅上漲(zhang),同(tong)時(shi)(shi)我國(guo)在(zai)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的關(guan)鍵原(yuan)料有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)的生產(chan)(chan)技術(shu)方(fang)面取(qu)得突破,有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)的生產(chan)(chan)技術(shu)在(zai)2005年(nian)前被幾家跨國(guo)公司壟斷,但目前我國(guo)已發展成(cheng)(cheng)為全球有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)第1大國(guo),這2個方(fang)面原(yuan)因(yin)使硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的價格從2011年(nian)起(qi)開始(shi)低于石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為大宗石(shi)(shi)油(you)基橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的80%~90%,成(cheng)(cheng)為廉價的合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始(shi)大規模替代石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將(jiang)極大拓展有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)(chan)業的市場空間,同(tong)時(shi)(shi)將(jiang)帶動硅(gui)(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)(gui)樹(shu)脂等其他有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)產(chan)(chan)品的消(xiao)費(fei)。