
硅橡膠是指主(zhu)鏈(lian)由硅(gui)(gui)和氧(yang)原(yuan)子交替構(gou)成,硅(gui)(gui)原(yuan)子上(shang)通常連有(you)兩個有(you)機(ji)基(ji)(ji)團的(de)橡膠(jiao)(jiao)。普通的(de)硅(gui)(gui)橡膠(jiao)(jiao)主(zhu)要(yao)由含(han)甲基(ji)(ji)和少量乙烯(xi)基(ji)(ji)的(de)硅(gui)(gui)氧(yang)鏈(lian)節組成。苯(ben)基(ji)(ji)的(de)引入(ru)可(ke)(ke)提(ti)高硅(gui)(gui)橡膠(jiao)(jiao)的(de)耐(nai)高、低溫(wen)(wen)性(xing)(xing)(xing)能(neng),三氟丙基(ji)(ji)及(ji)氰(qing)基(ji)(ji)的(de)引入(ru)則可(ke)(ke)提(ti)高硅(gui)(gui)橡膠(jiao)(jiao)的(de)耐(nai)溫(wen)(wen)及(ji)耐(nai)油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡膠(jiao)(jiao)耐(nai)低溫(wen)(wen)性(xing)(xing)(xing)能(neng)良(liang)好,一般(ban)在-55℃下(xia)仍能(neng)工作。引入(ru)苯(ben)基(ji)(ji)后,可(ke)(ke)達-73℃。硅(gui)(gui)橡膠(jiao)(jiao)的(de)耐(nai)熱性(xing)(xing)(xing)能(neng)也(ye)很突出,在180℃下(xia)可(ke)(ke)長期工作,稍高于200℃也(ye)能(neng)承受數周或更(geng)長時間仍有(you)彈(dan)性(xing)(xing)(xing),瞬時可(ke)(ke)耐(nai)300℃以上(shang)的(de)高溫(wen)(wen)。硅(gui)(gui)橡膠(jiao)(jiao)的(de)透氣性(xing)(xing)(xing)好,氧(yang)氣透過率在合(he)成聚合(he)物中(zhong)是較高的(de)。此外(wai),硅(gui)(gui)橡膠(jiao)(jiao)還具有(you)生理惰性(xing)(xing)(xing)、不會導致凝血的(de)突出特性(xing)(xing)(xing),因此在醫用(yong)領域應用(yong)廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分(fen)類的(de)方(fang)法很多,通常按(an)固化前的(de)形態分(fen)為固體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液(ye)體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)硫化溫(wen)(wen)度(du)分(fen)為室溫(wen)(wen)硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高溫(wen)(wen)硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)所用(yong)(yong)單體的(de)不同,可(ke)分(fen)為甲基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)性能和用(yong)(yong)途的(de)不同又(you)可(ke)分(fen)為通用(yong)(yong)型(xing)(xing)(xing)、超(chao)耐低溫(wen)(wen)型(xing)(xing)(xing)、超(chao)耐高溫(wen)(wen)型(xing)(xing)(xing)、高強力型(xing)(xing)(xing)、耐油(you)型(xing)(xing)(xing)、醫(yi)用(yong)(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)早期是(shi)由(you)美(mei)(mei)國以三氯化(hua)鐵(tie)為催(cui)化(hua)劑(ji)合(he)成的(de)。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)產(chan)品問(wen)世。1948年(nian),采用高(gao)(gao)比(bi)表(biao)面積(ji)的(de)氣(qi)相法白炭(tan)黑(hei)補(bu)強的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)研制成功,使(shi)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)性能(neng)躍升(sheng)到實用階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)技術的(de)基(ji)礎。從二甲基(ji)二氯硅(gui)(gui)烷(wan)合(he)成開始(shi)生(sheng)(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)國家有美(mei)(mei)國。俄(e)羅斯、德國、日本、韓國和中(zhong)(zhong)國等。中(zhong)(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)工業(ye)化(hua)研究始(shi)于1957年(nian),多家研究所和企(qi)業(ye)陸續開發(fa)出(chu)各種硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。到2003年(nian)底,中(zhong)(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)能(neng)力(li)為135千(qian)噸(dun),其(qi)中(zhong)(zhong)高(gao)(gao)溫膠(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)(gao)(gao)溫硫化(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是(shi)指(zhi)聚(ju)硅(gui)(gui)氧烷(wan)變成彈(dan)性體的過程是(shi)經(jing)過高(gao)(gao)(gao)溫(110-170℃)硫化(hua)成型(xing)的。它(ta)主要(yao)以高(gao)(gao)(gao)分子量的聚(ju)甲基乙(yi)烯基硅(gui)(gui)氧烷(wan)為(wei)生(sheng)膠(jiao)(jiao)(jiao),混入補強(qiang)填料、硫化(hua)劑等,在加熱加壓下硫化(hua)成彈(dan)性體。硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的補強(qiang)主要(yao)是(shi)各(ge)種類(lei)型(xing)的白炭黑(hei),可使硫化(hua)膠(jiao)(jiao)(jiao)的強(qiang)度增加數(shu)十倍。有時為(wei)了降低成本或改善膠(jiao)(jiao)(jiao)料性能(neng)(neng)及賦予硫化(hua)膠(jiao)(jiao)(jiao)各(ge)種特(te)殊的性能(neng)(neng),也加入相應(ying)的各(ge)種添加劑。硫化(hua)劑是(shi)各(ge)種有機過氧化(hua)物或加成反(fan)應(ying)催化(hua)劑。
加工(gong)成型方法(fa)如圖(tu)所示。一(yi)次(ci)硫化的目的是進行(xing)高分子鏈的交(jiao)聯反應;二次(ci)硫化的目的是進行(xing)補充交(jiao)聯、驅除硫化劑分解產物和(he)其他(ta)揮發性化合(he)物以穩定硫化膠(jiao)的各項性能。常用(yong)的設(she)備有開(kai)放式煉(lian)膠(jiao)機(ji)(ji)、捏合(he)機(ji)(ji)及真空密煉(lian)機(ji)(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特(te)(te)征是高(gao)溫(wen)(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度僅是天(tian)(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在200℃以上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)環(huan)境下,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保(bao)持一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)、回彈性(xing)(xing)(xing)和表面硬(ying)度,且力學性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無明顯變化(hua)(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化(hua)(hua)溫(wen)(wen)(wen)(wen)(wen)度一般為(wei)-70~-50℃,特(te)(te)殊配方(fang)可達-100℃,表明其(qi)(qi)低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)異。這對(dui)航(hang)空、宇(yu)航(hang)工業的(de)(de)(de)意義重(zhong)大(da)。(3)耐(nai)(nai)(nai)候性(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)氧、臭氧及紫外線等(deng)十(shi)分穩定(ding),在不加任何添加劑的(de)(de)(de)情(qing)況下,就具(ju)有優(you)良的(de)(de)(de)耐(nai)(nai)(nai)候性(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)和耐(nai)(nai)(nai)電(dian)弧(hu)性(xing)(xing)(xing)也非(fei)常好。(5)物(wu)理(li)機械(xie)(xie)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下的(de)(de)(de)物(wu)理(li)機械(xie)(xie)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)(wen)下,其(qi)(qi)物(wu)理(li)機械(xie)(xie)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)于通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油(you)及化(hua)(hua)學試(shi)劑性(xing)(xing)(xing)。普(pu)通(tong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有中(zhong)等(deng)的(de)(de)(de)耐(nai)(nai)(nai)油(you)、耐(nai)(nai)(nai)溶劑性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮(dan)、氧、二(er)氧化(hua)(hua)碳等(deng)氣(qi)體(ti)的(de)(de)(de)透氣(qi)性(xing)(xing)(xing)比天(tian)(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味(wei),無嗅,與人體(ti)組(zu)(zu)織不粘連,具(ju)有抗凝血作用(yong),對(dui)肌體(ti)組(zu)(zu)織的(de)(de)(de)反應(ying)性(xing)(xing)(xing)非(fei)常少。特(te)(te)別(bie)適合作為(wei)醫用(yong)材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)車(che)(che)(che)(che)工(gong)業(ye)協會統計,2012年(nian)(nian),汽(qi)車(che)(che)(che)(che)產(chan)銷分別(bie)達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)車(che)(che)(che)(che)工(gong)業(ye)硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)用(yong)量(liang)約達2.0萬t。根據觀(guan)研(yan)(yan)天下的(de)(de)新研(yan)(yan)究,增(zeng)加(jia)有(you)機硅(gui)(gui)材料在汽(qi)車(che)(che)(che)(che)零部件方面的(de)(de)用(yong)量(liang),可以大幅(fu)度(du)提(ti)(ti)高(gao)汽(qi)車(che)(che)(che)(che)的(de)(de)安(an)全性能,因此,汽(qi)車(che)(che)(che)(che)產(chan)量(liang)和單車(che)(che)(che)(che)用(yong)量(liang)水平的(de)(de)提(ti)(ti)高(gao)都將(jiang)推動汽(qi)車(che)(che)(che)(che)工(gong)業(ye)對硅(gui)(gui)橡(xiang)膠(jiao)需求的(de)(de)增(zeng)加(jia)。國(guo)(guo)家鼓勵自(zi)主(zhu)品(pin)牌(pai)的(de)(de)汽(qi)車(che)(che)(che)(che)發展,關鍵汽(qi)車(che)(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)(che)選用(yong)車(che)(che)(che)(che)型目錄(征求意見稿(gao))》為自(zi)主(zhu)品(pin)牌(pai)擴(kuo)大在政府(fu)采購的(de)(de)市場份額,為改變(bian)目前國(guo)(guo)內政府(fu)采購以合資品(pin)牌(pai)產(chan)品(pin)為主(zhu)的(de)(de)局面提(ti)(ti)供(gong)了保障(zhang)。促進自(zi)主(zhu)品(pin)牌(pai)發展,國(guo)(guo)產(chan)汽(qi)車(che)(che)(che)(che)業(ye)的(de)(de)繁榮將(jiang)為汽(qi)車(che)(che)(che)(che)膠(jiao)的(de)(de)應用(yong)提(ti)(ti)供(gong)有(you)力保障(zhang)。預測未來3年(nian)(nian),我國(guo)(guo)室溫硫化硅(gui)(gui)橡(xiang)膠(jiao)在汽(qi)車(che)(che)(che)(che)行業(ye)將(jiang)以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)是重要的非(fei)石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao),約占非(fei)石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)消(xiao)費量(liang)的98%。但因(yin)為(wei)石(shi)油(you)(you)價格(ge)的大(da)(da)幅上漲,同時我(wo)國在(zai)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)(gui)單體的生產(chan)技術方面取(qu)得突破(po),有(you)(you)機(ji)硅(gui)(gui)單體的生產(chan)技術在(zai)2005年前(qian)被(bei)幾家跨國公司壟斷,但目前(qian)我(wo)國已(yi)發展成(cheng)(cheng)為(wei)全球有(you)(you)機(ji)硅(gui)(gui)單體第(di)1大(da)(da)國,這2個方面原因(yin)使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的價格(ge)從(cong)2011年起開(kai)始低于石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao),僅約為(wei)大(da)(da)宗石(shi)油(you)(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)(cheng)為(wei)廉價的合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao),并開(kai)始大(da)(da)規模替代石(shi)油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)。這將極大(da)(da)拓(tuo)展有(you)(you)機(ji)硅(gui)(gui)產(chan)業的市場空(kong)間,同時將帶(dai)動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂等其他有(you)(you)機(ji)硅(gui)(gui)產(chan)品(pin)的消(xiao)費。