
硅橡膠是(shi)指主鏈由硅(gui)(gui)(gui)(gui)和氧(yang)原(yuan)子(zi)交(jiao)替構成(cheng),硅(gui)(gui)(gui)(gui)原(yuan)子(zi)上通(tong)常(chang)連有(you)兩個(ge)有(you)機基(ji)團(tuan)的(de)(de)橡(xiang)(xiang)膠。普通(tong)的(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠主要由含甲基(ji)和少量乙烯基(ji)的(de)(de)硅(gui)(gui)(gui)(gui)氧(yang)鏈節組(zu)成(cheng)。苯基(ji)的(de)(de)引(yin)入可(ke)(ke)提(ti)高(gao)(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)高(gao)(gao)、低(di)(di)溫(wen)(wen)(wen)性(xing)能(neng),三氟丙基(ji)及氰(qing)基(ji)的(de)(de)引(yin)入則可(ke)(ke)提(ti)高(gao)(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)溫(wen)(wen)(wen)及耐(nai)油性(xing)能(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠耐(nai)低(di)(di)溫(wen)(wen)(wen)性(xing)能(neng)良好(hao),一般在(zai)-55℃下仍(reng)能(neng)工作。引(yin)入苯基(ji)后(hou),可(ke)(ke)達-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐(nai)熱性(xing)能(neng)也很(hen)突出(chu),在(zai)180℃下可(ke)(ke)長(chang)(chang)期工作,稍高(gao)(gao)于200℃也能(neng)承受(shou)數周或(huo)更長(chang)(chang)時(shi)間仍(reng)有(you)彈性(xing),瞬時(shi)可(ke)(ke)耐(nai)300℃以上的(de)(de)高(gao)(gao)溫(wen)(wen)(wen)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)透氣(qi)性(xing)好(hao),氧(yang)氣(qi)透過率在(zai)合(he)成(cheng)聚合(he)物中是(shi)較高(gao)(gao)的(de)(de)。此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠還具有(you)生理惰性(xing)、不會導致凝血(xue)的(de)(de)突出(chu)特性(xing),因此在(zai)醫用(yong)領域應用(yong)廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分類的(de)(de)(de)方法(fa)很多,通常按(an)固(gu)化(hua)前的(de)(de)(de)形態分為(wei)固(gu)體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和(he)(he)液體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)硫(liu)化(hua)溫(wen)(wen)(wen)度分為(wei)室溫(wen)(wen)(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)溫(wen)(wen)(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)所用(yong)(yong)單體的(de)(de)(de)不(bu)同,可分為(wei)甲基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)性能(neng)和(he)(he)用(yong)(yong)途的(de)(de)(de)不(bu)同又可分為(wei)通用(yong)(yong)型(xing)、超耐(nai)(nai)低溫(wen)(wen)(wen)型(xing)、超耐(nai)(nai)高(gao)溫(wen)(wen)(wen)型(xing)、高(gao)強力型(xing)、耐(nai)(nai)油型(xing)、醫用(yong)(yong)型(xing)等等。
發展史
硅橡膠(jiao)早(zao)期是由美國以三(san)氯化(hua)(hua)鐵為催化(hua)(hua)劑合成(cheng)的(de)。1945年,硅橡膠(jiao)產品問世。1948年,采用高比表(biao)面積的(de)氣相法白炭黑補(bu)強的(de)硅橡膠(jiao)研制(zhi)成(cheng)功(gong),使(shi)硅橡膠(jiao)的(de)性能躍升到(dao)實用階段,奠(dian)定了現代硅橡膠(jiao)生(sheng)產技(ji)術的(de)基礎。從二甲基二氯硅烷合成(cheng)開(kai)始生(sheng)產硅橡膠(jiao)的(de)國家有(you)美國。俄羅(luo)斯、德(de)國、日本(ben)、韓國和(he)(he)中(zhong)(zhong)國等。中(zhong)(zhong)國硅橡膠(jiao)的(de)工業(ye)化(hua)(hua)研究始于1957年,多家研究所和(he)(he)企業(ye)陸續開(kai)發(fa)出各種硅橡膠(jiao)。到(dao)2003年底,中(zhong)(zhong)國硅橡膠(jiao)生(sheng)產能力為135千噸,其(qi)中(zhong)(zhong)高溫膠(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)(hua)(hua)(hua)硅(gui)橡膠(jiao)是(shi)(shi)(shi)指聚硅(gui)氧烷變成(cheng)(cheng)彈性體的(de)過程是(shi)(shi)(shi)經過高(gao)溫(110-170℃)硫(liu)化(hua)(hua)(hua)(hua)成(cheng)(cheng)型(xing)(xing)的(de)。它主要以高(gao)分(fen)子量(liang)的(de)聚甲基(ji)乙烯基(ji)硅(gui)氧烷為生(sheng)膠(jiao),混入補強填料、硫(liu)化(hua)(hua)(hua)(hua)劑等(deng),在加(jia)熱(re)加(jia)壓下硫(liu)化(hua)(hua)(hua)(hua)成(cheng)(cheng)彈性體。硅(gui)橡膠(jiao)的(de)補強主要是(shi)(shi)(shi)各種(zhong)(zhong)類型(xing)(xing)的(de)白炭黑,可使硫(liu)化(hua)(hua)(hua)(hua)膠(jiao)的(de)強度增加(jia)數十倍。有(you)時為了降低(di)成(cheng)(cheng)本或改善膠(jiao)料性能(neng)及賦予硫(liu)化(hua)(hua)(hua)(hua)膠(jiao)各種(zhong)(zhong)特殊的(de)性能(neng),也加(jia)入相應的(de)各種(zhong)(zhong)添加(jia)劑。硫(liu)化(hua)(hua)(hua)(hua)劑是(shi)(shi)(shi)各種(zhong)(zhong)有(you)機(ji)過氧化(hua)(hua)(hua)(hua)物或加(jia)成(cheng)(cheng)反應催化(hua)(hua)(hua)(hua)劑。
加工成(cheng)型方法如圖所示。一(yi)次硫(liu)(liu)化的目(mu)的是進行高(gao)分(fen)子鏈(lian)的交聯反應;二次硫(liu)(liu)化的目(mu)的是進行補充交聯、驅除硫(liu)(liu)化劑分(fen)解產(chan)物(wu)和其他(ta)揮發性化合物(wu)以穩(wen)定硫(liu)(liu)化膠(jiao)的各項性能。常用(yong)的設備(bei)有開(kai)放式(shi)煉膠(jiao)機、捏合機及(ji)真空(kong)密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)顯著的(de)(de)(de)特征是高溫(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常(chang)溫(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)強度僅是天(tian)然橡(xiang)(xiang)膠(jiao)或某些(xie)合成橡(xiang)(xiang)膠(jiao)的(de)(de)(de)一半,但(dan)在200℃以上(shang)的(de)(de)(de)高溫(wen)(wen)(wen)(wen)環境下,硅(gui)橡(xiang)(xiang)膠(jiao)仍(reng)能(neng)(neng)(neng)保持一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面(mian)硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)玻(bo)璃化溫(wen)(wen)(wen)(wen)度一般為(wei)-70~-50℃,特殊配方可達-100℃,表(biao)明其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對(dui)航(hang)空(kong)、宇航(hang)工(gong)業的(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)中Si-O-Si鍵對(dui)氧、臭(chou)氧及紫外線等(deng)(deng)十分穩定(ding),在不加任何添(tian)加劑(ji)的(de)(de)(de)情況下,就具(ju)(ju)有(you)優(you)良(liang)的(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)常(chang)溫(wen)(wen)(wen)(wen)下的(de)(de)(de)物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)膠(jiao)差,但(dan)在150℃的(de)(de)(de)高溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)下,其物(wu)(wu)理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)(xiang)膠(jiao)。(6)耐(nai)(nai)油(you)及化學試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)膠(jiao)具(ju)(ju)有(you)中等(deng)(deng)的(de)(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)膠(jiao)對(dui)空(kong)氣(qi)(qi)、氮、氧、二(er)氧化碳(tan)等(deng)(deng)氣(qi)(qi)體(ti)的(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)膠(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)無毒,無味,無嗅,與人體(ti)組織不粘(zhan)連,具(ju)(ju)有(you)抗凝血作用(yong),對(dui)肌體(ti)組織的(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特別適(shi)合作為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)(che)(che)工(gong)(gong)業(ye)(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)車(che)(che)(che)產銷分別達到1927.18萬輛和1930.64萬輛,同比分別增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)(che)(che)工(gong)(gong)業(ye)(ye)硅橡(xiang)(xiang)膠的用(yong)量(liang)約達2.0萬t。根據觀研(yan)天下的新研(yan)究,增(zeng)加有(you)機硅材料在(zai)汽(qi)(qi)車(che)(che)(che)零部件方面的用(yong)量(liang),可(ke)以(yi)(yi)大幅度(du)提高汽(qi)(qi)車(che)(che)(che)的安全性(xing)能,因此,汽(qi)(qi)車(che)(che)(che)產量(liang)和單(dan)車(che)(che)(che)用(yong)量(liang)水平的提高都(dou)將推動汽(qi)(qi)車(che)(che)(che)工(gong)(gong)業(ye)(ye)對硅橡(xiang)(xiang)膠需求(qiu)的增(zeng)加。國(guo)家鼓勵(li)自(zi)主(zhu)品(pin)(pin)牌(pai)的汽(qi)(qi)車(che)(che)(che)發展,關鍵(jian)汽(qi)(qi)車(che)(che)(che)零部件實現自(zi)主(zhu)化,《2012年(nian)(nian)度(du)黨政機關公務用(yong)車(che)(che)(che)選(xuan)用(yong)車(che)(che)(che)型目錄(征(zheng)求(qiu)意見稿)》為(wei)自(zi)主(zhu)品(pin)(pin)牌(pai)擴大在(zai)政府(fu)采(cai)購(gou)的市場份額,為(wei)改變目前(qian)國(guo)內(nei)政府(fu)采(cai)購(gou)以(yi)(yi)合(he)資品(pin)(pin)牌(pai)產品(pin)(pin)為(wei)主(zhu)的局面提供了保障。促進自(zi)主(zhu)品(pin)(pin)牌(pai)發展,國(guo)產汽(qi)(qi)車(che)(che)(che)業(ye)(ye)的繁(fan)榮將為(wei)汽(qi)(qi)車(che)(che)(che)膠的應用(yong)提供有(you)力(li)保障。預測未來3年(nian)(nian),我國(guo)室溫硫化硅橡(xiang)(xiang)膠在(zai)汽(qi)(qi)車(che)(che)(che)行(xing)業(ye)(ye)將以(yi)(yi)年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的(de)非(fei)石(shi)油(you)(you)(you)(you)基(ji)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠,約占非(fei)石(shi)油(you)(you)(you)(you)基(ji)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠消(xiao)費量(liang)的(de)98%。但(dan)因為(wei)(wei)石(shi)油(you)(you)(you)(you)價(jia)格的(de)大幅(fu)上(shang)漲,同時我國在硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)關鍵(jian)原料有(you)機(ji)硅(gui)(gui)(gui)單(dan)(dan)(dan)體(ti)的(de)生產(chan)技術(shu)方面取得突破(po),有(you)機(ji)硅(gui)(gui)(gui)單(dan)(dan)(dan)體(ti)的(de)生產(chan)技術(shu)在2005年(nian)前被幾家(jia)跨國公司壟(long)斷,但(dan)目前我國已(yi)發展成(cheng)(cheng)為(wei)(wei)全球有(you)機(ji)硅(gui)(gui)(gui)單(dan)(dan)(dan)體(ti)第1大國,這2個(ge)方面原因使硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)價(jia)格從2011年(nian)起開(kai)始(shi)(shi)低于石(shi)油(you)(you)(you)(you)基(ji)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠,僅約為(wei)(wei)大宗石(shi)油(you)(you)(you)(you)基(ji)橡(xiang)(xiang)膠的(de)80%~90%,成(cheng)(cheng)為(wei)(wei)廉價(jia)的(de)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠,并開(kai)始(shi)(shi)大規(gui)模替代石(shi)油(you)(you)(you)(you)基(ji)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠。這將極大拓展有(you)機(ji)硅(gui)(gui)(gui)產(chan)業的(de)市(shi)場(chang)空(kong)間,同時將帶動硅(gui)(gui)(gui)油(you)(you)(you)(you)、硅(gui)(gui)(gui)烷偶聯(lian)劑和硅(gui)(gui)(gui)樹脂等其他有(you)機(ji)硅(gui)(gui)(gui)產(chan)品的(de)消(xiao)費。