
硅橡膠是(shi)指(zhi)主鏈由(you)硅(gui)(gui)和氧(yang)原子交替構成(cheng),硅(gui)(gui)原子上通常(chang)連有兩(liang)個有機(ji)基(ji)(ji)團的橡膠(jiao)(jiao)。普通的硅(gui)(gui)橡膠(jiao)(jiao)主要由(you)含甲基(ji)(ji)和少(shao)量乙(yi)烯基(ji)(ji)的硅(gui)(gui)氧(yang)鏈節組成(cheng)。苯基(ji)(ji)的引(yin)入(ru)可提(ti)高(gao)硅(gui)(gui)橡膠(jiao)(jiao)的耐(nai)高(gao)、低溫(wen)性(xing)(xing)(xing)能(neng)(neng),三氟(fu)丙基(ji)(ji)及氰基(ji)(ji)的引(yin)入(ru)則(ze)可提(ti)高(gao)硅(gui)(gui)橡膠(jiao)(jiao)的耐(nai)溫(wen)及耐(nai)油性(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡膠(jiao)(jiao)耐(nai)低溫(wen)性(xing)(xing)(xing)能(neng)(neng)良(liang)好,一般(ban)在-55℃下仍能(neng)(neng)工作(zuo)。引(yin)入(ru)苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)橡膠(jiao)(jiao)的耐(nai)熱性(xing)(xing)(xing)能(neng)(neng)也(ye)很突出(chu),在180℃下可長期工作(zuo),稍高(gao)于200℃也(ye)能(neng)(neng)承(cheng)受數周或更(geng)長時間(jian)仍有彈性(xing)(xing)(xing),瞬時可耐(nai)300℃以上的高(gao)溫(wen)。硅(gui)(gui)橡膠(jiao)(jiao)的透氣性(xing)(xing)(xing)好,氧(yang)氣透過(guo)率在合成(cheng)聚合物中是(shi)較高(gao)的。此外,硅(gui)(gui)橡膠(jiao)(jiao)還具有生理惰性(xing)(xing)(xing)、不會導(dao)致凝血的突出(chu)特性(xing)(xing)(xing),因此在醫用(yong)領域應(ying)用(yong)廣泛。
主要品種
硅(gui)(gui)(gui)橡膠(jiao)分(fen)類的(de)方法很多,通(tong)常按固(gu)(gu)化前的(de)形態分(fen)為固(gu)(gu)體硅(gui)(gui)(gui)橡膠(jiao)和液體硅(gui)(gui)(gui)橡膠(jiao);按硫(liu)化溫(wen)度分(fen)為室溫(wen)硫(liu)化硅(gui)(gui)(gui)橡膠(jiao),高(gao)溫(wen)硫(liu)化硅(gui)(gui)(gui)橡膠(jiao);按所用(yong)單體的(de)不(bu)同,可(ke)分(fen)為甲(jia)基乙烯基硅(gui)(gui)(gui)橡膠(jiao),甲(jia)基苯基乙烯基硅(gui)(gui)(gui)橡膠(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡膠(jiao)等(deng);按性能和用(yong)途的(de)不(bu)同又可(ke)分(fen)為通(tong)用(yong)型、超耐低溫(wen)型、超耐高(gao)溫(wen)型、高(gao)強力型、耐油型、醫用(yong)型等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由美(mei)國(guo)以三氯化(hua)鐵(tie)為催化(hua)劑合成的。1945年,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)(chan)品(pin)問世。1948年,采用高比表面(mian)積(ji)的氣相法白炭黑(hei)補(bu)強的硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成功(gong),使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的性能躍(yue)升到(dao)實(shi)用階段,奠定了現代(dai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)技(ji)術的基(ji)礎。從二(er)甲(jia)基(ji)二(er)氯硅(gui)(gui)(gui)烷(wan)合成開始生(sheng)產(chan)(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)家(jia)有美(mei)國(guo)。俄羅(luo)斯、德(de)國(guo)、日本、韓國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的工業化(hua)研究(jiu)始于1957年,多家(jia)研究(jiu)所和(he)企業陸續開發(fa)出各種硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年底(di),中(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)能力為135千(qian)噸(dun),其中(zhong)高溫膠(jiao)(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao)是(shi)指聚硅(gui)(gui)氧(yang)烷變(bian)成(cheng)彈(dan)性(xing)體的(de)過程是(shi)經過高(gao)溫(110-170℃)硫(liu)(liu)化(hua)成(cheng)型的(de)。它(ta)主要(yao)以高(gao)分(fen)子量的(de)聚甲(jia)基(ji)乙烯基(ji)硅(gui)(gui)氧(yang)烷為生膠(jiao),混入補(bu)強填料、硫(liu)(liu)化(hua)劑(ji)(ji)等,在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)成(cheng)彈(dan)性(xing)體。硅(gui)(gui)橡(xiang)膠(jiao)的(de)補(bu)強主要(yao)是(shi)各種(zhong)(zhong)類(lei)型的(de)白(bai)炭黑(hei),可使(shi)硫(liu)(liu)化(hua)膠(jiao)的(de)強度增(zeng)加(jia)數十倍。有時為了降低成(cheng)本或(huo)改善(shan)膠(jiao)料性(xing)能及賦予(yu)硫(liu)(liu)化(hua)膠(jiao)各種(zhong)(zhong)特殊的(de)性(xing)能,也(ye)加(jia)入相應(ying)的(de)各種(zhong)(zhong)添(tian)加(jia)劑(ji)(ji)。硫(liu)(liu)化(hua)劑(ji)(ji)是(shi)各種(zhong)(zhong)有機過氧(yang)化(hua)物或(huo)加(jia)成(cheng)反應(ying)催(cui)化(hua)劑(ji)(ji)。
加工成型方(fang)法如圖所(suo)示。一(yi)次硫(liu)化(hua)(hua)的目的是進行高分子(zi)鏈的交(jiao)聯反應(ying);二次硫(liu)化(hua)(hua)的目的是進行補充(chong)交(jiao)聯、驅(qu)除(chu)硫(liu)化(hua)(hua)劑(ji)分解(jie)產物和(he)其他揮發性(xing)化(hua)(hua)合物以穩(wen)定硫(liu)化(hua)(hua)膠的各項性(xing)能。常用的設備有開放(fang)式煉膠機(ji)、捏(nie)合機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)特(te)(te)(te)征是高(gao)溫(wen)(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常(chang)溫(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅(jin)是天然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)半,但在200℃以上(shang)的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia)(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯(xian)變化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度(du)一(yi)般為-70~-50℃,特(te)(te)(te)殊配方可達(da)-100℃,表(biao)明其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)異。這對(dui)航(hang)空、宇航(hang)工(gong)業的(de)(de)(de)意義(yi)重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫外線等(deng)(deng)十分穩定(ding)(ding),在不加任何添加劑的(de)(de)(de)情況下(xia)(xia)(xia),就(jiu)具有(you)(you)優(you)(you)良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)(you)優(you)(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非(fei)常(chang)好。(5)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)(xia)(xia)的(de)(de)(de)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下(xia)(xia)(xia),其物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)于(yu)通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及化(hua)學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)(you)中等(deng)(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)碳等(deng)(deng)氣(qi)體(ti)的(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無毒(du),無味(wei),無嗅,與人體(ti)組織不粘連,具有(you)(you)抗凝血(xue)作用(yong),對(dui)肌體(ti)組織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)(te)(te)別適合作為醫(yi)用(yong)材料。
硅橡膠的用量
據中國(guo)汽車(che)(che)工業(ye)(ye)(ye)協(xie)會統計,2012年,汽車(che)(che)產(chan)銷分別達到1927.18萬(wan)(wan)輛和1930.64萬(wan)(wan)輛,同比分別增(zeng)長4.63%和4.33%,汽車(che)(che)工業(ye)(ye)(ye)硅(gui)橡膠的(de)(de)(de)(de)用(yong)(yong)(yong)(yong)量(liang)(liang)(liang)約達2.0萬(wan)(wan)t。根據觀(guan)研天下的(de)(de)(de)(de)新(xin)研究,增(zeng)加有機硅(gui)材(cai)料在(zai)汽車(che)(che)零部(bu)件方面的(de)(de)(de)(de)用(yong)(yong)(yong)(yong)量(liang)(liang)(liang),可以大(da)幅度提高汽車(che)(che)的(de)(de)(de)(de)安全性能,因此,汽車(che)(che)產(chan)量(liang)(liang)(liang)和單車(che)(che)用(yong)(yong)(yong)(yong)量(liang)(liang)(liang)水(shui)平的(de)(de)(de)(de)提高都將(jiang)推動汽車(che)(che)工業(ye)(ye)(ye)對硅(gui)橡膠需求的(de)(de)(de)(de)增(zeng)加。國(guo)家鼓勵(li)自(zi)(zi)主(zhu)品牌的(de)(de)(de)(de)汽車(che)(che)發(fa)展(zhan),關鍵汽車(che)(che)零部(bu)件實現自(zi)(zi)主(zhu)化,《2012年度黨政機關公務用(yong)(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)(yong)車(che)(che)型(xing)目錄(征求意見(jian)稿(gao))》為自(zi)(zi)主(zhu)品牌擴大(da)在(zai)政府采購的(de)(de)(de)(de)市(shi)場份額,為改變目前國(guo)內政府采購以合資品牌產(chan)品為主(zhu)的(de)(de)(de)(de)局面提供了保障。促進自(zi)(zi)主(zhu)品牌發(fa)展(zhan),國(guo)產(chan)汽車(che)(che)業(ye)(ye)(ye)的(de)(de)(de)(de)繁榮將(jiang)為汽車(che)(che)膠的(de)(de)(de)(de)應(ying)用(yong)(yong)(yong)(yong)提供有力保障。預測未來3年,我國(guo)室溫硫化硅(gui)橡膠在(zai)汽車(che)(che)行業(ye)(ye)(ye)將(jiang)以年均20%增(zeng)長。
此(ci)外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重要的(de)(de)非石(shi)(shi)油(you)基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消(xiao)費(fei)量的(de)(de)98%。但因為石(shi)(shi)油(you)價格(ge)的(de)(de)大幅(fu)上漲(zhang),同時我(wo)(wo)國(guo)在(zai)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關鍵原料有(you)機硅(gui)(gui)單體的(de)(de)生產(chan)技(ji)術(shu)方(fang)面取得突破,有(you)機硅(gui)(gui)單體的(de)(de)生產(chan)技(ji)術(shu)在(zai)2005年前被(bei)幾家跨國(guo)公司壟斷(duan),但目前我(wo)(wo)國(guo)已發(fa)展(zhan)成(cheng)為全球(qiu)有(you)機硅(gui)(gui)單體第1大國(guo),這2個方(fang)面原因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價格(ge)從2011年起(qi)開始低于石(shi)(shi)油(you)基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅約為大宗(zong)石(shi)(shi)油(you)基橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為廉(lian)價的(de)(de)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并(bing)開始大規模替(ti)代石(shi)(shi)油(you)基合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這將極大拓展(zhan)有(you)機硅(gui)(gui)產(chan)業的(de)(de)市(shi)場空間(jian),同時將帶動硅(gui)(gui)油(you)、硅(gui)(gui)烷(wan)偶(ou)聯劑和硅(gui)(gui)樹脂等其他有(you)機硅(gui)(gui)產(chan)品(pin)的(de)(de)消(xiao)費(fei)。