
硅橡膠是指主鏈由(you)硅(gui)(gui)(gui)和氧原子(zi)交替構成(cheng),硅(gui)(gui)(gui)原子(zi)上(shang)通常連有兩個有機(ji)基(ji)團(tuan)的橡(xiang)(xiang)膠。普(pu)通的硅(gui)(gui)(gui)橡(xiang)(xiang)膠主要(yao)由(you)含甲基(ji)和少量乙烯基(ji)的硅(gui)(gui)(gui)氧鏈節組成(cheng)。苯基(ji)的引入(ru)可(ke)(ke)提高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的耐(nai)高(gao)(gao)(gao)、低(di)溫性能(neng),三(san)氟(fu)丙基(ji)及(ji)氰(qing)基(ji)的引入(ru)則可(ke)(ke)提高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的耐(nai)溫及(ji)耐(nai)油(you)性能(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠耐(nai)低(di)溫性能(neng)良好,一般(ban)在(zai)-55℃下(xia)仍(reng)能(neng)工(gong)作(zuo)。引入(ru)苯基(ji)后(hou),可(ke)(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的耐(nai)熱性能(neng)也很突出,在(zai)180℃下(xia)可(ke)(ke)長期工(gong)作(zuo),稍(shao)高(gao)(gao)(gao)于200℃也能(neng)承受數周或(huo)更長時間仍(reng)有彈(dan)性,瞬時可(ke)(ke)耐(nai)300℃以上(shang)的高(gao)(gao)(gao)溫。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的透氣性好,氧氣透過率在(zai)合成(cheng)聚合物中是較高(gao)(gao)(gao)的。此(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠還具有生理惰性、不會導致凝血的突出特性,因此(ci)在(zai)醫用領(ling)域應(ying)用廣泛。
主要品種
硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)分(fen)(fen)類的(de)方(fang)法很多,通(tong)常按(an)固(gu)化(hua)前的(de)形態分(fen)(fen)為固(gu)體硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)和液體硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)硫化(hua)溫(wen)度分(fen)(fen)為室溫(wen)硫化(hua)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),高(gao)溫(wen)硫化(hua)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)所用(yong)單體的(de)不(bu)同,可(ke)分(fen)(fen)為甲(jia)(jia)基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao),甲(jia)(jia)基(ji)苯基(ji)乙烯(xi)基(ji)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)、氟硅(gui)(gui)(gui)(gui),腈硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)等;按(an)性能(neng)和用(yong)途的(de)不(bu)同又可(ke)分(fen)(fen)為通(tong)用(yong)型、超(chao)(chao)耐低溫(wen)型、超(chao)(chao)耐高(gao)溫(wen)型、高(gao)強力型、耐油(you)型、醫用(yong)型等等。
發展史
硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)早期是由美(mei)國以三氯化鐵為催化劑合(he)成的(de)(de)(de)。1945年(nian),硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)產(chan)品問世。1948年(nian),采用(yong)高比表面積(ji)的(de)(de)(de)氣相法白炭黑補強的(de)(de)(de)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)研(yan)制成功,使(shi)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)性能躍升(sheng)到實用(yong)階段,奠定了現代硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)技術的(de)(de)(de)基礎(chu)。從二甲基二氯硅(gui)(gui)烷合(he)成開始生產(chan)硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)國家有美(mei)國。俄羅斯、德國、日本(ben)、韓國和中國等。中國硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)工業(ye)化研(yan)究(jiu)始于(yu)1957年(nian),多家研(yan)究(jiu)所(suo)和企業(ye)陸續開發出(chu)各(ge)種硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)。到2003年(nian)底,中國硅(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)能力(li)為135千噸(dun),其中高溫膠(jiao)(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)(gao)溫硫(liu)(liu)(liu)化(hua)硅(gui)橡膠是(shi)指聚硅(gui)氧烷變成(cheng)彈(dan)性體的過(guo)程(cheng)是(shi)經(jing)過(guo)高(gao)(gao)溫(110-170℃)硫(liu)(liu)(liu)化(hua)成(cheng)型的。它主(zhu)要(yao)以高(gao)(gao)分子量的聚甲基乙烯基硅(gui)氧烷為生膠,混入補強填(tian)料(liao)、硫(liu)(liu)(liu)化(hua)劑等,在加(jia)熱加(jia)壓下(xia)硫(liu)(liu)(liu)化(hua)成(cheng)彈(dan)性體。硅(gui)橡膠的補強主(zhu)要(yao)是(shi)各種類型的白炭黑(hei),可使硫(liu)(liu)(liu)化(hua)膠的強度增加(jia)數十(shi)倍。有時(shi)為了降低成(cheng)本或改(gai)善膠料(liao)性能及賦予硫(liu)(liu)(liu)化(hua)膠各種特殊的性能,也(ye)加(jia)入相應的各種添加(jia)劑。硫(liu)(liu)(liu)化(hua)劑是(shi)各種有機過(guo)氧化(hua)物或加(jia)成(cheng)反應催化(hua)劑。
加工成型方法如圖所示。一次硫化(hua)的目的是進行高分子鏈的交(jiao)聯反應(ying);二次硫化(hua)的目的是進行補充交(jiao)聯、驅除(chu)硫化(hua)劑(ji)分解產物和其他揮(hui)發性化(hua)合物以穩定硫化(hua)膠的各項性能。常(chang)用的設(she)備(bei)有開(kai)放(fang)式煉膠機、捏合機及真空密(mi)煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特(te)(te)征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度僅(jin)是(shi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或(huo)某些(xie)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在(zai)(zai)200℃以(yi)上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保(bao)持一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無明(ming)顯變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃(li)化溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)(te)殊(shu)配方可達-100℃,表(biao)明(ming)其(qi)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優異(yi)。這對(dui)航空、宇航工業的(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)氧、臭氧及紫外線(xian)等(deng)十分穩定(ding),在(zai)(zai)不加任何添加劑的(de)(de)(de)情況下(xia),就具有優良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有優異(yi)的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)下(xia)的(de)(de)(de)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下(xia),其(qi)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優于(yu)通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及化學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有中(zhong)等(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室(shi)溫(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)(qi)(qi)、氮、氧、二(er)氧化碳等(deng)氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)(de)透(tou)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人(ren)體(ti)(ti)組(zu)織(zhi)不粘連(lian),具有抗凝血作用(yong),對(dui)肌體(ti)(ti)組(zu)織(zhi)的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)(te)別適(shi)合作為醫(yi)用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)產(chan)銷分別達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同(tong)比分別增(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)硅橡(xiang)膠的(de)(de)(de)用量約達2.0萬(wan)t。根據觀研天下的(de)(de)(de)新(xin)研究,增(zeng)加(jia)有(you)(you)機(ji)硅材料(liao)在(zai)(zai)汽(qi)(qi)(qi)車(che)零部(bu)件方面的(de)(de)(de)用量,可以大幅度(du)提高汽(qi)(qi)(qi)車(che)的(de)(de)(de)安全性能(neng),因此,汽(qi)(qi)(qi)車(che)產(chan)量和單車(che)用量水平的(de)(de)(de)提高都將(jiang)推動汽(qi)(qi)(qi)車(che)工業(ye)(ye)(ye)對硅橡(xiang)膠需求的(de)(de)(de)增(zeng)加(jia)。國(guo)家鼓勵自(zi)(zi)主(zhu)品牌的(de)(de)(de)汽(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)車(che)零部(bu)件實(shi)現自(zi)(zi)主(zhu)化,《2012年(nian)度(du)黨政(zheng)機(ji)關公務(wu)用車(che)選用車(che)型目錄(征求意見稿(gao))》為(wei)自(zi)(zi)主(zhu)品牌擴大在(zai)(zai)政(zheng)府(fu)采(cai)購的(de)(de)(de)市(shi)場份額,為(wei)改變(bian)目前國(guo)內政(zheng)府(fu)采(cai)購以合(he)資品牌產(chan)品為(wei)主(zhu)的(de)(de)(de)局面提供了保障。促進自(zi)(zi)主(zhu)品牌發展,國(guo)產(chan)汽(qi)(qi)(qi)車(che)業(ye)(ye)(ye)的(de)(de)(de)繁榮將(jiang)為(wei)汽(qi)(qi)(qi)車(che)膠的(de)(de)(de)應用提供有(you)(you)力保障。預測未來3年(nian),我國(guo)室溫硫化硅橡(xiang)膠在(zai)(zai)汽(qi)(qi)(qi)車(che)行業(ye)(ye)(ye)將(jiang)以年(nian)均20%增(zeng)長(chang)。
此外,硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的(de)非石(shi)油基合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油基合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消費量(liang)的(de)98%。但因為石(shi)油價(jia)格(ge)的(de)大(da)幅上漲,同時我(wo)國(guo)在(zai)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)關鍵原料有(you)(you)機(ji)硅單體的(de)生產技(ji)術(shu)方面(mian)取得(de)突(tu)破,有(you)(you)機(ji)硅單體的(de)生產技(ji)術(shu)在(zai)2005年前被幾家跨國(guo)公司壟斷,但目前我(wo)國(guo)已發展(zhan)成為全球有(you)(you)機(ji)硅單體第1大(da)國(guo),這(zhe)2個方面(mian)原因使硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)價(jia)格(ge)從2011年起開(kai)(kai)始低于石(shi)油基合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為大(da)宗(zong)石(shi)油基橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)80%~90%,成為廉價(jia)的(de)合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開(kai)(kai)始大(da)規模替(ti)代(dai)石(shi)油基合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將(jiang)極(ji)大(da)拓(tuo)展(zhan)有(you)(you)機(ji)硅產業的(de)市場空間,同時將(jiang)帶動硅油、硅烷偶聯(lian)劑(ji)和硅樹脂等其他有(you)(you)機(ji)硅產品的(de)消費。