硅橡膠是(shi)(shi)指主(zhu)鏈(lian)由硅(gui)(gui)和氧(yang)原子交替構成(cheng),硅(gui)(gui)原子上通常連有(you)(you)兩個(ge)有(you)(you)機基(ji)團的(de)(de)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)主(zhu)要由含甲基(ji)和少量乙烯(xi)基(ji)的(de)(de)硅(gui)(gui)氧(yang)鏈(lian)節組成(cheng)。苯(ben)(ben)基(ji)的(de)(de)引(yin)入(ru)可提高(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐高(gao)、低溫(wen)性(xing)能(neng),三氟丙(bing)基(ji)及氰(qing)基(ji)的(de)(de)引(yin)入(ru)則可提高(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐溫(wen)及耐油性(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低溫(wen)性(xing)能(neng)良好(hao),一般在-55℃下(xia)仍能(neng)工作(zuo)。引(yin)入(ru)苯(ben)(ben)基(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)耐熱(re)性(xing)能(neng)也很突(tu)出,在180℃下(xia)可長(chang)期工作(zuo),稍高(gao)于(yu)200℃也能(neng)承(cheng)受數周或更長(chang)時間仍有(you)(you)彈性(xing),瞬時可耐300℃以上的(de)(de)高(gao)溫(wen)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)透氣性(xing)好(hao),氧(yang)氣透過率(lv)在合(he)成(cheng)聚合(he)物中是(shi)(shi)較高(gao)的(de)(de)。此外(wai),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有(you)(you)生理惰性(xing)、不(bu)會導致凝血(xue)的(de)(de)突(tu)出特性(xing),因此在醫用(yong)領(ling)域(yu)應用(yong)廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)分(fen)類的(de)方(fang)法很多,通(tong)常按(an)固化(hua)前的(de)形(xing)態(tai)分(fen)為(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)和(he)液體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)硫化(hua)溫度(du)分(fen)為(wei)室溫硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao),高(gao)溫硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)所用(yong)(yong)單體的(de)不同(tong),可分(fen)為(wei)甲基(ji)(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲基(ji)(ji)(ji)(ji)苯基(ji)(ji)(ji)(ji)乙烯(xi)基(ji)(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)等;按(an)性(xing)能和(he)用(yong)(yong)途(tu)的(de)不同(tong)又可分(fen)為(wei)通(tong)用(yong)(yong)型(xing)(xing)(xing)、超耐低(di)溫型(xing)(xing)(xing)、超耐高(gao)溫型(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用(yong)(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期(qi)是(shi)由美國(guo)(guo)以三氯化鐵(tie)為催化劑合成的(de)。1945年(nian)(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)產品問世。1948年(nian)(nian),采用高(gao)比(bi)表(biao)面積(ji)的(de)氣相法白炭黑補強的(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)研(yan)制(zhi)成功,使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)性能躍升到實用階段,奠定(ding)了現(xian)代硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產技術(shu)的(de)基礎。從(cong)二甲(jia)基二氯硅(gui)(gui)(gui)烷合成開始(shi)生產硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)國(guo)(guo)家有美國(guo)(guo)。俄羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和中國(guo)(guo)等(deng)。中國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)工業化研(yan)究(jiu)始(shi)于1957年(nian)(nian),多家研(yan)究(jiu)所和企業陸續開發(fa)出各種硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)(nian)底,中國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)生產能力為135千(qian)噸(dun),其中高(gao)溫膠(jiao)(jiao)100千(qian)噸(dun)。
高(gao)溫硫化硅橡(xiang)膠(jiao)
高(gao)溫硫化(hua)(hua)(hua)(hua)(hua)硅橡膠是(shi)(shi)指聚(ju)硅氧(yang)烷變成彈(dan)(dan)性(xing)體的過程(cheng)是(shi)(shi)經過高(gao)溫(110-170℃)硫化(hua)(hua)(hua)(hua)(hua)成型的。它主要以(yi)高(gao)分子(zi)量的聚(ju)甲基乙烯基硅氧(yang)烷為生膠,混入(ru)補強填料、硫化(hua)(hua)(hua)(hua)(hua)劑(ji)等,在加熱加壓下(xia)硫化(hua)(hua)(hua)(hua)(hua)成彈(dan)(dan)性(xing)體。硅橡膠的補強主要是(shi)(shi)各(ge)種類(lei)型的白炭黑(hei),可(ke)使硫化(hua)(hua)(hua)(hua)(hua)膠的強度增(zeng)加數十倍。有時為了降低(di)成本或改(gai)善(shan)膠料性(xing)能及賦(fu)予硫化(hua)(hua)(hua)(hua)(hua)膠各(ge)種特(te)殊的性(xing)能,也(ye)加入(ru)相應(ying)的各(ge)種添(tian)加劑(ji)。硫化(hua)(hua)(hua)(hua)(hua)劑(ji)是(shi)(shi)各(ge)種有機過氧(yang)化(hua)(hua)(hua)(hua)(hua)物或加成反應(ying)催化(hua)(hua)(hua)(hua)(hua)劑(ji)。
加工成(cheng)型方法(fa)如圖所示。一(yi)次硫化(hua)(hua)(hua)的(de)(de)目的(de)(de)是進行(xing)(xing)高(gao)分(fen)子鏈(lian)的(de)(de)交聯反應;二次硫化(hua)(hua)(hua)的(de)(de)目的(de)(de)是進行(xing)(xing)補充交聯、驅(qu)除硫化(hua)(hua)(hua)劑分(fen)解產物和(he)其他揮發性化(hua)(hua)(hua)合物以穩(wen)定硫化(hua)(hua)(hua)膠(jiao)(jiao)的(de)(de)各項性能。常用的(de)(de)設備有開放式煉(lian)膠(jiao)(jiao)機、捏(nie)合機及真空密(mi)煉(lian)機。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡膠(jiao)(jiao)顯(xian)(xian)著的(de)(de)特(te)征是高(gao)(gao)溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)(chang)溫(wen)(wen)(wen)下(xia)(xia)硅(gui)橡膠(jiao)(jiao)的(de)(de)強(qiang)度僅(jin)是天然(ran)橡膠(jiao)(jiao)或(huo)某些(xie)合(he)成橡膠(jiao)(jiao)的(de)(de)一半(ban),但(dan)在200℃以上的(de)(de)高(gao)(gao)溫(wen)(wen)(wen)環境下(xia)(xia),硅(gui)橡膠(jiao)(jiao)仍能(neng)(neng)保(bao)持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)(wu)明顯(xian)(xian)變化(hua)。(2)低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)橡膠(jiao)(jiao)的(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方(fang)可達-100℃,表明其(qi)(qi)低(di)(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)異。這對航空(kong)、宇航工業(ye)的(de)(de)意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡膠(jiao)(jiao)中Si-O-Si鍵對氧、臭(chou)氧及紫(zi)外(wai)線等十(shi)分穩定,在不加(jia)任何添加(jia)劑的(de)(de)情(qing)況下(xia)(xia),就具(ju)有優(you)(you)良的(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡膠(jiao)(jiao)具(ju)有優(you)(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)(chang)好。(5)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡膠(jiao)(jiao)常(chang)(chang)(chang)溫(wen)(wen)(wen)下(xia)(xia)的(de)(de)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比(bi)通用(yong)(yong)橡膠(jiao)(jiao)差,但(dan)在150℃的(de)(de)高(gao)(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)低(di)(di)溫(wen)(wen)(wen)下(xia)(xia),其(qi)(qi)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)于通用(yong)(yong)橡膠(jiao)(jiao)。(6)耐(nai)油及化(hua)學(xue)試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)橡膠(jiao)(jiao)具(ju)有中等的(de)(de)耐(nai)油、耐(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)硅(gui)橡膠(jiao)(jiao)對空(kong)氣(qi)(qi)(qi)、氮、氧、二(er)氧化(hua)碳等氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)透氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)橡膠(jiao)(jiao)高(gao)(gao)出30-50倍(bei)。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡膠(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人(ren)體(ti)(ti)組織不粘連,具(ju)有抗凝血作用(yong)(yong),對肌體(ti)(ti)組織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)(chang)少(shao)。特(te)別適合(he)作為醫用(yong)(yong)材(cai)料。
硅(gui)橡(xiang)膠的用量
據(ju)中國(guo)汽(qi)(qi)車(che)(che)(che)工業(ye)協會統計,2012年(nian),汽(qi)(qi)車(che)(che)(che)產(chan)銷分別(bie)達到1927.18萬(wan)(wan)輛和(he)1930.64萬(wan)(wan)輛,同比分別(bie)增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)車(che)(che)(che)工業(ye)硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)用量(liang)約達2.0萬(wan)(wan)t。根據(ju)觀(guan)研天下的(de)(de)新研究,增(zeng)加有(you)機(ji)硅(gui)(gui)材料在汽(qi)(qi)車(che)(che)(che)零部(bu)件方面的(de)(de)用量(liang),可以(yi)大(da)幅度(du)提(ti)高汽(qi)(qi)車(che)(che)(che)的(de)(de)安全性(xing)能,因此,汽(qi)(qi)車(che)(che)(che)產(chan)量(liang)和(he)單車(che)(che)(che)用量(liang)水(shui)平的(de)(de)提(ti)高都(dou)將(jiang)推動(dong)汽(qi)(qi)車(che)(che)(che)工業(ye)對硅(gui)(gui)橡(xiang)膠(jiao)需求的(de)(de)增(zeng)加。國(guo)家鼓(gu)勵(li)自主(zhu)(zhu)品牌的(de)(de)汽(qi)(qi)車(che)(che)(che)發(fa)(fa)展,關鍵汽(qi)(qi)車(che)(che)(che)零部(bu)件實現(xian)自主(zhu)(zhu)化,《2012年(nian)度(du)黨政機(ji)關公務用車(che)(che)(che)選用車(che)(che)(che)型目(mu)錄(征求意見稿)》為自主(zhu)(zhu)品牌擴大(da)在政府(fu)采購的(de)(de)市場份額,為改變目(mu)前國(guo)內(nei)政府(fu)采購以(yi)合資(zi)品牌產(chan)品為主(zhu)(zhu)的(de)(de)局(ju)面提(ti)供(gong)了(le)保(bao)障。促進自主(zhu)(zhu)品牌發(fa)(fa)展,國(guo)產(chan)汽(qi)(qi)車(che)(che)(che)業(ye)的(de)(de)繁榮將(jiang)為汽(qi)(qi)車(che)(che)(che)膠(jiao)的(de)(de)應用提(ti)供(gong)有(you)力保(bao)障。預測(ce)未來3年(nian),我國(guo)室溫硫(liu)化硅(gui)(gui)橡(xiang)膠(jiao)在汽(qi)(qi)車(che)(che)(che)行(xing)業(ye)將(jiang)以(yi)年(nian)均20%增(zeng)長(chang)。
此外,硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)是重(zhong)要(yao)的(de)(de)非石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao),約占非石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)消(xiao)費量的(de)(de)98%。但因(yin)為(wei)石(shi)油(you)(you)價(jia)(jia)格的(de)(de)大幅上漲,同(tong)時(shi)我國(guo)在硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)關鍵原(yuan)料(liao)有(you)(you)(you)機硅單體的(de)(de)生產技(ji)術方面取得突破,有(you)(you)(you)機硅單體的(de)(de)生產技(ji)術在2005年(nian)前被(bei)幾家跨國(guo)公司壟斷(duan),但目(mu)前我國(guo)已(yi)發(fa)展成(cheng)(cheng)為(wei)全球有(you)(you)(you)機硅單體第1大國(guo),這(zhe)2個方面原(yuan)因(yin)使硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)價(jia)(jia)格從2011年(nian)起開始低于(yu)石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao),僅約為(wei)大宗石(shi)油(you)(you)基(ji)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉價(jia)(jia)的(de)(de)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao),并開始大規模替代石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。這(zhe)將(jiang)極大拓展有(you)(you)(you)機硅產業的(de)(de)市場空間,同(tong)時(shi)將(jiang)帶動硅油(you)(you)、硅烷(wan)偶(ou)聯劑和硅樹脂等(deng)其他有(you)(you)(you)機硅產品的(de)(de)消(xiao)費。