硅橡膠是指主鏈由硅(gui)(gui)(gui)和(he)氧原(yuan)子交(jiao)替(ti)構成(cheng),硅(gui)(gui)(gui)原(yuan)子上(shang)通常連有(you)(you)兩個有(you)(you)機基(ji)(ji)團的(de)(de)(de)橡(xiang)膠(jiao)。普通的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)主要由含甲(jia)基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧鏈節組成(cheng)。苯基(ji)(ji)的(de)(de)(de)引入(ru)可提(ti)高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)高(gao)、低(di)溫(wen)(wen)性(xing)(xing)能(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引入(ru)則可提(ti)高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)溫(wen)(wen)及耐(nai)油性(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)耐(nai)低(di)溫(wen)(wen)性(xing)(xing)能(neng)良好(hao),一(yi)般在(zai)-55℃下仍能(neng)工(gong)作。引入(ru)苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)熱性(xing)(xing)能(neng)也(ye)很突出(chu),在(zai)180℃下可長(chang)期工(gong)作,稍高(gao)于200℃也(ye)能(neng)承受(shou)數周或更長(chang)時間仍有(you)(you)彈(dan)性(xing)(xing),瞬時可耐(nai)300℃以(yi)上(shang)的(de)(de)(de)高(gao)溫(wen)(wen)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)透氣性(xing)(xing)好(hao),氧氣透過率在(zai)合(he)成(cheng)聚合(he)物中是較高(gao)的(de)(de)(de)。此(ci)外(wai),硅(gui)(gui)(gui)橡(xiang)膠(jiao)還具有(you)(you)生(sheng)理惰(duo)性(xing)(xing)、不會(hui)導致凝血的(de)(de)(de)突出(chu)特性(xing)(xing),因此(ci)在(zai)醫(yi)用領域(yu)應(ying)用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)分(fen)類(lei)的(de)(de)方法很多,通常按(an)固(gu)化前的(de)(de)形態分(fen)為(wei)固(gu)體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)和液體硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)硫化溫(wen)(wen)度分(fen)為(wei)室溫(wen)(wen)硫化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),高溫(wen)(wen)硫化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao);按(an)所用(yong)單體的(de)(de)不同,可(ke)分(fen)為(wei)甲基乙(yi)烯(xi)基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),甲基苯基乙(yi)烯(xi)基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)、氟硅(gui),腈(jing)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)等;按(an)性能和用(yong)途(tu)的(de)(de)不同又(you)可(ke)分(fen)為(wei)通用(yong)型、超(chao)耐(nai)低(di)溫(wen)(wen)型、超(chao)耐(nai)高溫(wen)(wen)型、高強(qiang)力型、耐(nai)油型、醫用(yong)型等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是(shi)由美(mei)國(guo)(guo)(guo)以(yi)三氯化(hua)鐵為催化(hua)劑合成(cheng)的。1945年(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)品問世(shi)。1948年(nian),采用(yong)高比(bi)表面(mian)積的氣相法白炭(tan)黑補強的硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使(shi)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的性能躍升到(dao)實用(yong)階段,奠定了現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術的基礎。從二甲基二氯硅(gui)烷合成(cheng)開(kai)始生產(chan)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家有美(mei)國(guo)(guo)(guo)。俄羅(luo)斯、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中國(guo)(guo)(guo)等。中國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的工(gong)業(ye)(ye)化(hua)研(yan)究始于(yu)1957年(nian),多家研(yan)究所(suo)和企(qi)業(ye)(ye)陸(lu)續開(kai)發(fa)出各種(zhong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)能力為135千(qian)噸(dun),其(qi)中高溫膠(jiao)(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)(gao)溫硫化(hua)(hua)硅(gui)橡(xiang)膠(jiao)是(shi)指聚(ju)硅(gui)氧(yang)(yang)烷變成彈性體的過(guo)程(cheng)是(shi)經過(guo)高(gao)(gao)溫(110-170℃)硫化(hua)(hua)成型的。它(ta)主要以高(gao)(gao)分(fen)子量的聚(ju)甲基乙烯(xi)基硅(gui)氧(yang)(yang)烷為(wei)生膠(jiao),混(hun)入(ru)補強填料(liao)、硫化(hua)(hua)劑(ji)(ji)等,在加熱加壓下硫化(hua)(hua)成彈性體。硅(gui)橡(xiang)膠(jiao)的補強主要是(shi)各(ge)種(zhong)類型的白炭(tan)黑,可使硫化(hua)(hua)膠(jiao)的強度增加數十倍(bei)。有(you)時為(wei)了(le)降低成本或改(gai)善(shan)膠(jiao)料(liao)性能及賦予硫化(hua)(hua)膠(jiao)各(ge)種(zhong)特(te)殊的性能,也加入(ru)相(xiang)應的各(ge)種(zhong)添(tian)加劑(ji)(ji)。硫化(hua)(hua)劑(ji)(ji)是(shi)各(ge)種(zhong)有(you)機(ji)過(guo)氧(yang)(yang)化(hua)(hua)物或加成反應催化(hua)(hua)劑(ji)(ji)。
加(jia)工(gong)成型方法如圖所(suo)示。一次(ci)硫化(hua)(hua)的目的是進行高分子鏈的交(jiao)聯(lian)反應;二(er)次(ci)硫化(hua)(hua)的目的是進行補充(chong)交(jiao)聯(lian)、驅除硫化(hua)(hua)劑分解產物(wu)和其(qi)他揮(hui)發性(xing)化(hua)(hua)合(he)物(wu)以穩定硫化(hua)(hua)膠的各項性(xing)能。常用的設備有開放式(shi)煉膠機、捏合(he)機及真(zhen)空密煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)特(te)征是高(gao)溫(wen)(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)強(qiang)度(du)僅是天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)一半,但(dan)在(zai)200℃以上的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)環境下,硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)保持(chi)一定的(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面(mian)硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明(ming)顯變化。(2)低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)玻璃化溫(wen)(wen)(wen)(wen)(wen)度(du)一般(ban)為(wei)-70~-50℃,特(te)殊(shu)配方可達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這對(dui)(dui)航(hang)空、宇航(hang)工業的(de)(de)意義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵(jian)對(dui)(dui)氧(yang)(yang)、臭(chou)氧(yang)(yang)及紫(zi)外線(xian)等十分穩定,在(zai)不加(jia)任何添加(jia)劑的(de)(de)情(qing)況下,就具(ju)(ju)有(you)(you)優(you)良的(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)優(you)異的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)(wen)(wen)下的(de)(de)物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)(wen)(wen)(wen)下,其物(wu)理機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化學(xue)試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)中(zhong)等的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑性(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)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化碳等氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)透氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無毒(du),無味(wei),無嗅,與(yu)人(ren)體(ti)(ti)組織不粘連,具(ju)(ju)有(you)(you)抗凝血作用(yong)(yong),對(dui)(dui)肌體(ti)(ti)組織的(de)(de)反(fan)應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特(te)別適(shi)合作為(wei)醫(yi)用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)工業協會統計,2012年,汽(qi)(qi)(qi)(qi)車(che)產銷分別(bie)達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比分別(bie)增長4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)工業硅橡(xiang)(xiang)膠的(de)(de)用(yong)(yong)量約達2.0萬(wan)t。根據觀研(yan)天下的(de)(de)新(xin)研(yan)究,增加有(you)機硅材料在汽(qi)(qi)(qi)(qi)車(che)零(ling)部件方面(mian)的(de)(de)用(yong)(yong)量,可以(yi)大(da)幅度提高汽(qi)(qi)(qi)(qi)車(che)的(de)(de)安全性能(neng),因此(ci),汽(qi)(qi)(qi)(qi)車(che)產量和單(dan)車(che)用(yong)(yong)量水平的(de)(de)提高都(dou)將(jiang)推動汽(qi)(qi)(qi)(qi)車(che)工業對硅橡(xiang)(xiang)膠需求(qiu)的(de)(de)增加。國(guo)(guo)家鼓(gu)勵自(zi)主(zhu)(zhu)品牌的(de)(de)汽(qi)(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)(qi)車(che)零(ling)部件實現自(zi)主(zhu)(zhu)化,《2012年度黨政(zheng)機關公(gong)務用(yong)(yong)車(che)選用(yong)(yong)車(che)型(xing)目(mu)錄(征求(qiu)意(yi)見稿)》為(wei)自(zi)主(zhu)(zhu)品牌擴大(da)在政(zheng)府采購的(de)(de)市(shi)場(chang)份額,為(wei)改變目(mu)前國(guo)(guo)內政(zheng)府采購以(yi)合資品牌產品為(wei)主(zhu)(zhu)的(de)(de)局面(mian)提供了保障(zhang)。促進自(zi)主(zhu)(zhu)品牌發展,國(guo)(guo)產汽(qi)(qi)(qi)(qi)車(che)業的(de)(de)繁榮將(jiang)為(wei)汽(qi)(qi)(qi)(qi)車(che)膠的(de)(de)應(ying)用(yong)(yong)提供有(you)力保障(zhang)。預(yu)測未來3年,我國(guo)(guo)室溫硫化硅橡(xiang)(xiang)膠在汽(qi)(qi)(qi)(qi)車(che)行(xing)業將(jiang)以(yi)年均20%增長。
此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠是重要的(de)非石油(you)(you)(you)基(ji)(ji)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠,約占非石油(you)(you)(you)基(ji)(ji)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠消(xiao)費量的(de)98%。但因為(wei)石油(you)(you)(you)價(jia)格的(de)大(da)(da)幅上漲,同(tong)時我國在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)關鍵原料有(you)機(ji)硅(gui)(gui)(gui)單體的(de)生產技(ji)術(shu)(shu)方面(mian)取(qu)得突破,有(you)機(ji)硅(gui)(gui)(gui)單體的(de)生產技(ji)術(shu)(shu)在(zai)2005年前被(bei)幾家跨國公(gong)司(si)壟斷,但目前我國已發(fa)展(zhan)成為(wei)全(quan)球有(you)機(ji)硅(gui)(gui)(gui)單體第1大(da)(da)國,這2個方面(mian)原因使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)價(jia)格從2011年起(qi)開始低(di)于石油(you)(you)(you)基(ji)(ji)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠,僅約為(wei)大(da)(da)宗石油(you)(you)(you)基(ji)(ji)橡(xiang)(xiang)(xiang)(xiang)膠的(de)80%~90%,成為(wei)廉(lian)價(jia)的(de)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠,并開始大(da)(da)規模替代石油(you)(you)(you)基(ji)(ji)合(he)成橡(xiang)(xiang)(xiang)(xiang)膠。這將極大(da)(da)拓展(zhan)有(you)機(ji)硅(gui)(gui)(gui)產業的(de)市場空(kong)間,同(tong)時將帶動硅(gui)(gui)(gui)油(you)(you)(you)、硅(gui)(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)(gui)樹脂等其他(ta)有(you)機(ji)硅(gui)(gui)(gui)產品的(de)消(xiao)費。