
硅橡膠是指主(zhu)鏈(lian)由硅(gui)(gui)(gui)和氧(yang)(yang)原(yuan)子交替構成(cheng)(cheng),硅(gui)(gui)(gui)原(yuan)子上通常連有(you)(you)兩個有(you)(you)機基團的(de)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。普通的(de)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)主(zhu)要(yao)由含甲基和少量乙(yi)烯(xi)基的(de)硅(gui)(gui)(gui)氧(yang)(yang)鏈(lian)節組(zu)成(cheng)(cheng)。苯基的(de)引入可提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)高(gao)、低(di)溫(wen)性(xing)(xing)(xing)能(neng)(neng),三氟(fu)丙基及氰基的(de)引入則可提高(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)溫(wen)及耐(nai)油性(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)耐(nai)低(di)溫(wen)性(xing)(xing)(xing)能(neng)(neng)良好,一般在(zai)-55℃下仍能(neng)(neng)工(gong)作。引入苯基后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)熱性(xing)(xing)(xing)能(neng)(neng)也(ye)很突(tu)出,在(zai)180℃下可長(chang)期工(gong)作,稍高(gao)于200℃也(ye)能(neng)(neng)承受數(shu)周或(huo)更(geng)長(chang)時(shi)間(jian)仍有(you)(you)彈(dan)性(xing)(xing)(xing),瞬時(shi)可耐(nai)300℃以(yi)上的(de)高(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)透(tou)氣性(xing)(xing)(xing)好,氧(yang)(yang)氣透(tou)過率在(zai)合成(cheng)(cheng)聚合物中是較高(gao)的(de)。此(ci)(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)還具(ju)有(you)(you)生理惰性(xing)(xing)(xing)、不會導(dao)致凝血的(de)突(tu)出特性(xing)(xing)(xing),因此(ci)(ci)在(zai)醫用(yong)領域應(ying)用(yong)廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)分類的方法(fa)很多(duo),通常按(an)固化(hua)(hua)前的形(xing)態(tai)分為(wei)固體(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)和液體(ti)硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)硫(liu)化(hua)(hua)溫(wen)(wen)度分為(wei)室溫(wen)(wen)硫(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao),高溫(wen)(wen)硫(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)膠(jiao)(jiao);按(an)所用單體(ti)的不同,可分為(wei)甲基乙烯基硅(gui)(gui)橡(xiang)膠(jiao)(jiao),甲基苯基乙烯基硅(gui)(gui)橡(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)等;按(an)性能和用途的不同又(you)可分為(wei)通用型(xing)、超耐低溫(wen)(wen)型(xing)、超耐高溫(wen)(wen)型(xing)、高強(qiang)力型(xing)、耐油型(xing)、醫(yi)用型(xing)等等。
發展史
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由美(mei)國(guo)以三氯(lv)化(hua)鐵為(wei)催化(hua)劑合成(cheng)的(de)(de)。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年(nian),采用(yong)高比表面積的(de)(de)氣(qi)相法(fa)白炭黑補強的(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成(cheng)功(gong),使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)性能躍升(sheng)到實用(yong)階段,奠定了(le)現代硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產技術的(de)(de)基礎。從(cong)二(er)甲基二(er)氯(lv)硅(gui)(gui)烷合成(cheng)開始生(sheng)(sheng)產硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)國(guo)家有美(mei)國(guo)。俄(e)羅斯、德國(guo)、日本、韓國(guo)和(he)中國(guo)等。中國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)工業化(hua)研究始于1957年(nian),多家研究所和(he)企(qi)業陸續開發出各種硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)底,中國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產能力為(wei)135千(qian)噸(dun),其中高溫膠(jiao)(jiao)(jiao)100千(qian)噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化硅橡膠(jiao)是指聚硅氧烷變成(cheng)彈(dan)性(xing)體的(de)過(guo)程是經過(guo)高(gao)溫(110-170℃)硫(liu)化成(cheng)型(xing)的(de)。它主(zhu)要以高(gao)分子量的(de)聚甲基(ji)(ji)乙烯基(ji)(ji)硅氧烷為生膠(jiao),混入(ru)補(bu)(bu)強(qiang)填料(liao)、硫(liu)化劑(ji)等(deng),在加熱加壓(ya)下硫(liu)化成(cheng)彈(dan)性(xing)體。硅橡膠(jiao)的(de)補(bu)(bu)強(qiang)主(zhu)要是各(ge)種(zhong)類型(xing)的(de)白炭(tan)黑,可使硫(liu)化膠(jiao)的(de)強(qiang)度(du)增加數(shu)十倍。有時為了降低成(cheng)本(ben)或(huo)改善(shan)膠(jiao)料(liao)性(xing)能(neng)(neng)及賦予硫(liu)化膠(jiao)各(ge)種(zhong)特殊的(de)性(xing)能(neng)(neng),也加入(ru)相應的(de)各(ge)種(zhong)添加劑(ji)。硫(liu)化劑(ji)是各(ge)種(zhong)有機過(guo)氧化物(wu)或(huo)加成(cheng)反應催化劑(ji)。
加(jia)工成(cheng)型方法如圖所示。一次硫(liu)(liu)(liu)化(hua)的(de)目的(de)是(shi)進行高分子鏈的(de)交聯(lian)反(fan)應;二次硫(liu)(liu)(liu)化(hua)的(de)目的(de)是(shi)進行補充交聯(lian)、驅除硫(liu)(liu)(liu)化(hua)劑分解產物(wu)和其他揮發性(xing)化(hua)合物(wu)以(yi)穩定硫(liu)(liu)(liu)化(hua)膠(jiao)的(de)各項(xiang)性(xing)能。常用的(de)設備有開放(fang)式煉膠(jiao)機、捏合機及真空密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)特(te)征(zheng)是(shi)(shi)高溫(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)(wen)下(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度(du)僅是(shi)(shi)天(tian)(tian)然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合(he)成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)高溫(wen)(wen)(wen)(wen)環境下(xia),硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)保(bao)持(chi)一(yi)定的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面硬度(du),且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明(ming)顯(xian)變化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度(du)一(yi)般為(wei)-70~-50℃,特(te)殊配方可(ke)達-100℃,表明(ming)其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這對航空、宇(yu)航工業的(de)(de)(de)意義重大(da)。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭(chou)氧(yang)及(ji)紫外線等(deng)十分穩定,在不(bu)加(jia)任何添加(jia)劑(ji)的(de)(de)(de)情況下(xia),就具(ju)有優(you)良的(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常好(hao)。(5)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)(de)物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)高溫(wen)(wen)(wen)(wen)和(he)(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)下(xia),其物(wu)理(li)機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于(yu)通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐油(you)(you)及(ji)化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有中等(deng)的(de)(de)(de)耐油(you)(you)、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣體(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣、氮(dan)、氧(yang)、二氧(yang)化碳等(deng)氣體(ti)的(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)(tian)然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(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)組(zu)織不(bu)粘連,具(ju)有抗凝血作(zuo)用(yong),對肌體(ti)組(zu)織的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合(he)作(zuo)為(wei)醫用(yong)材料。
硅橡膠的用量
據中國汽(qi)車(che)(che)(che)工業(ye)協會統(tong)計,2012年,汽(qi)車(che)(che)(che)產銷分別(bie)達到1927.18萬輛和(he)1930.64萬輛,同比分別(bie)增長(chang)4.63%和(he)4.33%,汽(qi)車(che)(che)(che)工業(ye)硅(gui)橡(xiang)膠的(de)(de)用(yong)量(liang)(liang)約(yue)達2.0萬t。根據觀(guan)研(yan)天(tian)下的(de)(de)新研(yan)究(jiu),增加有機(ji)硅(gui)材(cai)料在(zai)汽(qi)車(che)(che)(che)零(ling)部(bu)件方面的(de)(de)用(yong)量(liang)(liang),可(ke)以(yi)大(da)(da)幅度提高汽(qi)車(che)(che)(che)的(de)(de)安全性能,因此(ci),汽(qi)車(che)(che)(che)產量(liang)(liang)和(he)單車(che)(che)(che)用(yong)量(liang)(liang)水平的(de)(de)提高都將(jiang)(jiang)推動(dong)汽(qi)車(che)(che)(che)工業(ye)對硅(gui)橡(xiang)膠需求的(de)(de)增加。國家鼓勵自(zi)主品(pin)牌的(de)(de)汽(qi)車(che)(che)(che)發(fa)(fa)展(zhan),關(guan)鍵汽(qi)車(che)(che)(che)零(ling)部(bu)件實現自(zi)主化,《2012年度黨政(zheng)機(ji)關(guan)公(gong)務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目(mu)錄(征求意見稿)》為(wei)(wei)自(zi)主品(pin)牌擴大(da)(da)在(zai)政(zheng)府采購(gou)的(de)(de)市場份額,為(wei)(wei)改變目(mu)前國內政(zheng)府采購(gou)以(yi)合(he)資品(pin)牌產品(pin)為(wei)(wei)主的(de)(de)局面提供了保障。促(cu)進自(zi)主品(pin)牌發(fa)(fa)展(zhan),國產汽(qi)車(che)(che)(che)業(ye)的(de)(de)繁榮(rong)將(jiang)(jiang)為(wei)(wei)汽(qi)車(che)(che)(che)膠的(de)(de)應用(yong)提供有力保障。預測未來3年,我國室溫硫化硅(gui)橡(xiang)膠在(zai)汽(qi)車(che)(che)(che)行業(ye)將(jiang)(jiang)以(yi)年均20%增長(chang)。
此(ci)外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重要的(de)(de)(de)非石(shi)油(you)(you)基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非石(shi)油(you)(you)基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消(xiao)費(fei)量(liang)的(de)(de)(de)98%。但(dan)因為(wei)石(shi)油(you)(you)價格的(de)(de)(de)大(da)幅(fu)上(shang)漲,同時我(wo)國(guo)在硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)關鍵原料(liao)有機(ji)(ji)硅(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技術方(fang)面取得(de)突(tu)破,有機(ji)(ji)硅(gui)(gui)單(dan)體的(de)(de)(de)生產(chan)技術在2005年前(qian)被幾家跨國(guo)公司壟(long)斷,但(dan)目前(qian)我(wo)國(guo)已(yi)發展(zhan)成(cheng)為(wei)全球有機(ji)(ji)硅(gui)(gui)單(dan)體第(di)1大(da)國(guo),這2個方(fang)面原因使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)價格從(cong)2011年起開始低于石(shi)油(you)(you)基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約為(wei)大(da)宗石(shi)油(you)(you)基橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)為(wei)廉價的(de)(de)(de)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開始大(da)規模(mo)替代石(shi)油(you)(you)基合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將極大(da)拓展(zhan)有機(ji)(ji)硅(gui)(gui)產(chan)業的(de)(de)(de)市場空間,同時將帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯(lian)劑和硅(gui)(gui)樹脂等其他有機(ji)(ji)硅(gui)(gui)產(chan)品(pin)的(de)(de)(de)消(xiao)費(fei)。