硅橡膠是指主鏈(lian)(lian)由硅(gui)(gui)(gui)(gui)和(he)氧原子(zi)交替構(gou)成(cheng),硅(gui)(gui)(gui)(gui)原子(zi)上(shang)通常連有(you)(you)兩個有(you)(you)機基團(tuan)的橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。普通的硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)主要(yao)由含甲基和(he)少量乙烯基的硅(gui)(gui)(gui)(gui)氧鏈(lian)(lian)節組成(cheng)。苯基的引入可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)(nai)(nai)高(gao)、低溫性(xing)能(neng),三(san)氟丙基及氰(qing)基的引入則可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)(nai)(nai)溫及耐(nai)(nai)(nai)(nai)油性(xing)能(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)耐(nai)(nai)(nai)(nai)低溫性(xing)能(neng)良好(hao),一般在(zai)-55℃下(xia)仍(reng)能(neng)工作。引入苯基后,可達-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的耐(nai)(nai)(nai)(nai)熱性(xing)能(neng)也(ye)很突出,在(zai)180℃下(xia)可長期工作,稍高(gao)于200℃也(ye)能(neng)承受數周或更長時間仍(reng)有(you)(you)彈性(xing),瞬時可耐(nai)(nai)(nai)(nai)300℃以(yi)上(shang)的高(gao)溫。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的透氣性(xing)好(hao),氧氣透過率在(zai)合成(cheng)聚合物中是較高(gao)的。此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)還具有(you)(you)生理惰性(xing)、不會導(dao)致凝血的突出特性(xing),因此(ci)在(zai)醫用領域應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)分(fen)(fen)(fen)類的方法很多,通(tong)常按固化(hua)前的形態(tai)分(fen)(fen)(fen)為(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao);按硫化(hua)溫(wen)(wen)度分(fen)(fen)(fen)為(wei)室溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao),高(gao)(gao)溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao);按所(suo)用(yong)單(dan)體的不同,可分(fen)(fen)(fen)為(wei)甲基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)等;按性能和用(yong)途的不同又可分(fen)(fen)(fen)為(wei)通(tong)用(yong)型(xing)(xing)(xing)、超耐低溫(wen)(wen)型(xing)(xing)(xing)、超耐高(gao)(gao)溫(wen)(wen)型(xing)(xing)(xing)、高(gao)(gao)強(qiang)力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美國(guo)(guo)以(yi)三(san)氯化鐵為催化劑合成(cheng)的(de)(de)。1945年,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年,采用(yong)高(gao)比表面積的(de)(de)氣相法(fa)白(bai)炭黑補強的(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研制(zhi)成(cheng)功(gong),使硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)性能躍(yue)升到(dao)(dao)實(shi)用(yong)階段,奠定了現代硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產技術的(de)(de)基(ji)礎。從(cong)二甲基(ji)二氯硅(gui)(gui)(gui)烷(wan)合成(cheng)開始(shi)生產硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)國(guo)(guo)家有美國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本(ben)、韓國(guo)(guo)和(he)中(zhong)國(guo)(guo)等(deng)。中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)工業化研究始(shi)于1957年,多家研究所(suo)和(he)企業陸續(xu)開發出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)(dao)2003年底,中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產能力為135千(qian)噸,其(qi)中(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)(gao)溫(wen)(wen)硫化(hua)硅(gui)(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)(gui)氧烷(wan)變成(cheng)(cheng)彈性(xing)體(ti)的(de)過程是(shi)(shi)經過高(gao)(gao)溫(wen)(wen)(110-170℃)硫化(hua)成(cheng)(cheng)型(xing)的(de)。它主要以高(gao)(gao)分子量的(de)聚甲基乙烯基硅(gui)(gui)氧烷(wan)為(wei)生膠(jiao)(jiao),混(hun)入(ru)補強(qiang)填料、硫化(hua)劑(ji)(ji)等,在加(jia)熱加(jia)壓下硫化(hua)成(cheng)(cheng)彈性(xing)體(ti)。硅(gui)(gui)橡膠(jiao)(jiao)的(de)補強(qiang)主要是(shi)(shi)各種(zhong)類型(xing)的(de)白炭黑(hei),可(ke)使硫化(hua)膠(jiao)(jiao)的(de)強(qiang)度增加(jia)數十倍。有時為(wei)了降低(di)成(cheng)(cheng)本或改善(shan)膠(jiao)(jiao)料性(xing)能及(ji)賦予硫化(hua)膠(jiao)(jiao)各種(zhong)特(te)殊的(de)性(xing)能,也加(jia)入(ru)相應的(de)各種(zhong)添加(jia)劑(ji)(ji)。硫化(hua)劑(ji)(ji)是(shi)(shi)各種(zhong)有機過氧化(hua)物或加(jia)成(cheng)(cheng)反應催化(hua)劑(ji)(ji)。
加工(gong)成型(xing)方法如(ru)圖所示。一(yi)次硫(liu)化(hua)的(de)(de)目的(de)(de)是進行高(gao)分(fen)子鏈的(de)(de)交聯反(fan)應;二次硫(liu)化(hua)的(de)(de)目的(de)(de)是進行補充交聯、驅除硫(liu)化(hua)劑分(fen)解(jie)產物(wu)和其他揮發性(xing)(xing)化(hua)合物(wu)以穩定硫(liu)化(hua)膠的(de)(de)各項性(xing)(xing)能。常(chang)用的(de)(de)設備有開放式煉(lian)膠機、捏合機及真空密煉(lian)機。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特(te)征是高(gao)溫(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)下(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)僅是天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或(huo)某(mou)些合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半,但(dan)(dan)在(zai)200℃以上的(de)(de)高(gao)溫(wen)環境(jing)下(xia),硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻璃化溫(wen)度(du)一般為-70~-50℃,特(te)殊(shu)配方可達-100℃,表(biao)明其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對航(hang)空、宇航(hang)工業的(de)(de)意(yi)義重(zhong)大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及紫外線等(deng)十分(fen)穩(wen)定,在(zai)不(bu)加任何添加劑的(de)(de)情況下(xia),就具有(you)優(you)良的(de)(de)耐候性(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)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常好。(5)物(wu)理機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)下(xia)的(de)(de)物(wu)理機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)(dan)在(zai)150℃的(de)(de)高(gao)溫(wen)和-50℃的(de)(de)低溫(wen)下(xia),其物(wu)理機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐油及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)中等(deng)的(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(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)。室溫(wen)下(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)(qi)(qi)、氮(dan)、氧(yang)(yang)、二氧(yang)(yang)化碳等(deng)氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)透(tou)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人體(ti)(ti)組織不(bu)粘連,具有(you)抗(kang)凝血(xue)作用,對肌體(ti)(ti)組織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適(shi)合(he)作為醫用材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業協會統計,2012年,汽(qi)(qi)(qi)車(che)(che)(che)產銷分(fen)別達(da)到1927.18萬輛和1930.64萬輛,同比分(fen)別增長4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業硅(gui)橡(xiang)膠的用(yong)(yong)(yong)量約達(da)2.0萬t。根據觀研(yan)天下的新研(yan)究,增加有機(ji)硅(gui)材料在汽(qi)(qi)(qi)車(che)(che)(che)零部(bu)件方面(mian)的用(yong)(yong)(yong)量,可以大(da)(da)幅(fu)度提高汽(qi)(qi)(qi)車(che)(che)(che)的安全性能,因(yin)此,汽(qi)(qi)(qi)車(che)(che)(che)產量和單車(che)(che)(che)用(yong)(yong)(yong)量水平的提高都將(jiang)推(tui)動汽(qi)(qi)(qi)車(che)(che)(che)工(gong)業對硅(gui)橡(xiang)膠需求(qiu)的增加。國家(jia)鼓勵自(zi)(zi)主品牌的汽(qi)(qi)(qi)車(che)(che)(che)發(fa)展,關鍵汽(qi)(qi)(qi)車(che)(che)(che)零部(bu)件實現自(zi)(zi)主化(hua),《2012年度黨政(zheng)機(ji)關公務用(yong)(yong)(yong)車(che)(che)(che)選用(yong)(yong)(yong)車(che)(che)(che)型目錄(征求(qiu)意(yi)見稿(gao))》為自(zi)(zi)主品牌擴大(da)(da)在政(zheng)府(fu)采購的市(shi)場(chang)份額,為改(gai)變目前(qian)國內政(zheng)府(fu)采購以合資品牌產品為主的局面(mian)提供了保(bao)障。促進自(zi)(zi)主品牌發(fa)展,國產汽(qi)(qi)(qi)車(che)(che)(che)業的繁榮將(jiang)為汽(qi)(qi)(qi)車(che)(che)(che)膠的應用(yong)(yong)(yong)提供有力保(bao)障。預測未來3年,我國室溫(wen)硫化(hua)硅(gui)橡(xiang)膠在汽(qi)(qi)(qi)車(che)(che)(che)行業將(jiang)以年均20%增長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)是(shi)重要(yao)的(de)(de)非石(shi)油(you)(you)基合成橡(xiang)膠(jiao),約(yue)占(zhan)非石(shi)油(you)(you)基合成橡(xiang)膠(jiao)消費量的(de)(de)98%。但(dan)因(yin)為石(shi)油(you)(you)價(jia)格(ge)的(de)(de)大(da)(da)幅上漲,同(tong)時我(wo)國(guo)(guo)在硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)關鍵原料有機硅(gui)(gui)單體的(de)(de)生產技術(shu)方面取(qu)得突破,有機硅(gui)(gui)單體的(de)(de)生產技術(shu)在2005年前被幾家跨國(guo)(guo)公司壟斷,但(dan)目前我(wo)國(guo)(guo)已(yi)發展成為全球有機硅(gui)(gui)單體第1大(da)(da)國(guo)(guo),這(zhe)2個(ge)方面原因(yin)使硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)價(jia)格(ge)從2011年起開始低(di)于(yu)石(shi)油(you)(you)基合成橡(xiang)膠(jiao),僅(jin)約(yue)為大(da)(da)宗石(shi)油(you)(you)基橡(xiang)膠(jiao)的(de)(de)80%~90%,成為廉價(jia)的(de)(de)合成橡(xiang)膠(jiao),并(bing)開始大(da)(da)規(gui)模替代石(shi)油(you)(you)基合成橡(xiang)膠(jiao)。這(zhe)將(jiang)(jiang)極大(da)(da)拓(tuo)展有機硅(gui)(gui)產業的(de)(de)市場空間,同(tong)時將(jiang)(jiang)帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷(wan)偶聯劑和(he)硅(gui)(gui)樹脂等(deng)其他有機硅(gui)(gui)產品的(de)(de)消費。