硅橡膠是指主(zhu)鏈由硅(gui)(gui)和氧原子交替構成,硅(gui)(gui)原子上通(tong)常連有(you)(you)兩(liang)個有(you)(you)機基團的(de)(de)橡(xiang)(xiang)膠。普通(tong)的(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠主(zhu)要由含甲基和少量乙烯基的(de)(de)硅(gui)(gui)氧鏈節組成。苯基的(de)(de)引入可(ke)提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐高(gao)(gao)、低溫性(xing)(xing)(xing)能(neng)(neng),三氟丙基及(ji)氰(qing)基的(de)(de)引入則可(ke)提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐溫及(ji)耐油性(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠耐低溫性(xing)(xing)(xing)能(neng)(neng)良(liang)好,一般(ban)在(zai)-55℃下仍能(neng)(neng)工(gong)作。引入苯基后,可(ke)達(da)-73℃。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐熱性(xing)(xing)(xing)能(neng)(neng)也很突(tu)出,在(zai)180℃下可(ke)長(chang)期工(gong)作,稍高(gao)(gao)于200℃也能(neng)(neng)承受數周或更長(chang)時(shi)間仍有(you)(you)彈性(xing)(xing)(xing),瞬時(shi)可(ke)耐300℃以上的(de)(de)高(gao)(gao)溫。硅(gui)(gui)橡(xiang)(xiang)膠的(de)(de)透氣性(xing)(xing)(xing)好,氧氣透過率(lv)在(zai)合成聚(ju)合物中是較高(gao)(gao)的(de)(de)。此外(wai),硅(gui)(gui)橡(xiang)(xiang)膠還具(ju)有(you)(you)生(sheng)理惰(duo)性(xing)(xing)(xing)、不會導致凝血(xue)的(de)(de)突(tu)出特性(xing)(xing)(xing),因(yin)此在(zai)醫用領域(yu)應用廣泛。
主要品種
硅橡(xiang)膠分類的方法很(hen)多(duo),通常(chang)按固化
前的形態(tai)分為固體(ti)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和(he)液(ye)體(ti)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按硫化溫度分為室(shi)溫硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)(gao)(gao)溫硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按所(suo)用(yong)(yong)單體(ti)的不(bu)同,可(ke)分為甲基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯(xi)基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等(deng);按性能和(he)用(yong)(yong)途的不(bu)同又可(ke)分為通用(yong)(yong)型(xing)(xing)、超(chao)耐低溫型(xing)(xing)、超(chao)耐高(gao)(gao)(gao)溫型(xing)(xing)、高(gao)(gao)(gao)強力型(xing)(xing)、耐油型(xing)(xing)、醫(yi)用(yong)(yong)型(xing)(xing)等(deng)等(deng)。
發(fa)展(zhan)史
硅橡膠(jiao)(jiao)(jiao)早期是(shi)由(you)美(mei)國以三氯化鐵為催化劑(ji)合成的。1945年(nian)(nian),硅橡膠(jiao)(jiao)(jiao)產品問世。1948年(nian)(nian),采用高(gao)比表面積(ji)的氣相法(fa)白炭黑(hei)補強的硅橡膠(jiao)(jiao)(jiao)研(yan)(yan)制成功,使硅橡膠(jiao)(jiao)(jiao)的性能躍升到實用階(jie)段(duan),奠定(ding)了現(xian)代硅橡膠(jiao)(jiao)(jiao)生(sheng)(sheng)(sheng)產技(ji)術的基礎。從二甲(jia)基二氯硅烷合成開(kai)(kai)始生(sheng)(sheng)(sheng)產硅橡膠(jiao)(jiao)(jiao)的國家有美(mei)國。俄羅斯、德(de)國、日本(ben)、韓國和(he)中國等。中國硅橡膠(jiao)(jiao)(jiao)的工業(ye)(ye)化研(yan)(yan)究(jiu)始于1957年(nian)(nian),多(duo)家研(yan)(yan)究(jiu)所和(he)企(qi)業(ye)(ye)陸續開(kai)(kai)發出各種硅橡膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底,中國硅橡膠(jiao)(jiao)(jiao)生(sheng)(sheng)(sheng)產能力為135千噸(dun),其中高(gao)溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)(jiao)是指聚硅(gui)(gui)氧(yang)(yang)烷變成(cheng)彈(dan)性(xing)體的(de)過程(cheng)是經過高(gao)溫(wen)(110-170℃)硫(liu)化(hua)成(cheng)型的(de)。它(ta)主要以高(gao)分子量的(de)聚甲基乙(yi)烯基硅(gui)(gui)氧(yang)(yang)烷為(wei)生(sheng)膠(jiao)(jiao),混(hun)入補強填料(liao)、硫(liu)化(hua)劑(ji)等,在加(jia)熱加(jia)壓下(xia)硫(liu)化(hua)成(cheng)彈(dan)性(xing)體。硅(gui)(gui)橡膠(jiao)(jiao)的(de)補強主要是各(ge)種(zhong)類(lei)型的(de)白炭黑,可使(shi)硫(liu)化(hua)膠(jiao)(jiao)的(de)強度增(zeng)加(jia)數十倍。有(you)時(shi)為(wei)了降(jiang)低成(cheng)本或改(gai)善(shan)膠(jiao)(jiao)料(liao)性(xing)能及(ji)賦予硫(liu)化(hua)膠(jiao)(jiao)各(ge)種(zhong)特殊(shu)的(de)性(xing)能,也(ye)加(jia)入相應(ying)的(de)各(ge)種(zhong)添加(jia)劑(ji)。硫(liu)化(hua)劑(ji)是各(ge)種(zhong)有(you)機過氧(yang)(yang)化(hua)物或加(jia)成(cheng)反應(ying)催化(hua)劑(ji)。
加工成型(xing)方法如圖所示。一次硫化(hua)(hua)的目的是進行(xing)高(gao)分子鏈的交聯反(fan)應;二次硫化(hua)(hua)的目的是進行(xing)補充交聯、驅(qu)除硫化(hua)(hua)劑分解產物和(he)其他揮發(fa)性化(hua)(hua)合物以穩定(ding)硫化(hua)(hua)膠(jiao)的各(ge)項性能。常用(yong)的設備有開放(fang)式煉(lian)膠(jiao)機(ji)、捏合機(ji)及(ji)真空密煉(lian)機(ji)。
主要(yao)性(xing)能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯(xian)著(zhu)的特(te)征是高溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的強(qiang)度僅是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的一半(ban),但(dan)在200℃以上的高溫(wen)(wen)(wen)環(huan)境(jing)下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍(reng)能(neng)(neng)(neng)保持一定(ding)的柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度,且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)(wu)明(ming)顯(xian)變化(hua)(hua)。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的玻璃(li)化(hua)(hua)溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方可達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這(zhe)對(dui)航(hang)空、宇(yu)航(hang)工業的意(yi)義重(zhong)大。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵(jian)對(dui)氧、臭氧及紫外(wai)線等十(shi)分穩定(ding),在不(bu)加任何(he)添(tian)加劑的情(qing)況下,就具有(you)優良的耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具有(you)優異的絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常溫(wen)(wen)(wen)下的物(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)在150℃的高溫(wen)(wen)(wen)和-50℃的低(di)溫(wen)(wen)(wen)下,其物(wu)理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐油及化(hua)(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具有(you)中等的耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對(dui)空氣(qi)、氮、氧、二氧化(hua)(hua)碳(tan)等氣(qi)體的透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高出30-50倍(bei)。(8)生理(li)(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)(wu)(wu)毒,無(wu)(wu)(wu)味,無(wu)(wu)(wu)嗅,與(yu)人體組織不(bu)粘(zhan)連,具有(you)抗(kang)凝血作用,對(dui)肌體組織的反應性(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作為醫用材(cai)料。
硅橡膠的用量(liang)
據中(zhong)國(guo)(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)協會統計,2012年(nian),汽(qi)(qi)(qi)(qi)車(che)(che)產銷分別達到(dao)1927.18萬輛和1930.64萬輛,同比分別增(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)用(yong)量(liang)約達2.0萬t。根據觀研天下的(de)(de)(de)(de)新研究,增(zeng)加有機硅(gui)材(cai)料在(zai)汽(qi)(qi)(qi)(qi)車(che)(che)零部件方(fang)面的(de)(de)(de)(de)用(yong)量(liang),可以(yi)大(da)幅度提(ti)高汽(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)(de)(de)安全(quan)性能,因此(ci),汽(qi)(qi)(qi)(qi)車(che)(che)產量(liang)和單車(che)(che)用(yong)量(liang)水平的(de)(de)(de)(de)提(ti)高都將推動(dong)汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)對硅(gui)橡(xiang)膠(jiao)需求(qiu)的(de)(de)(de)(de)增(zeng)加。國(guo)(guo)(guo)家鼓勵自主(zhu)(zhu)品(pin)牌(pai)(pai)的(de)(de)(de)(de)汽(qi)(qi)(qi)(qi)車(che)(che)發(fa)展,關鍵(jian)汽(qi)(qi)(qi)(qi)車(che)(che)零部件實現自主(zhu)(zhu)化,《2012年(nian)度黨政機關公(gong)務用(yong)車(che)(che)選用(yong)車(che)(che)型(xing)目(mu)錄(征求(qiu)意見稿)》為(wei)(wei)自主(zhu)(zhu)品(pin)牌(pai)(pai)擴大(da)在(zai)政府(fu)采購的(de)(de)(de)(de)市(shi)場(chang)份額,為(wei)(wei)改(gai)變目(mu)前國(guo)(guo)(guo)內政府(fu)采購以(yi)合資品(pin)牌(pai)(pai)產品(pin)為(wei)(wei)主(zhu)(zhu)的(de)(de)(de)(de)局面提(ti)供(gong)了保(bao)(bao)障。促(cu)進(jin)自主(zhu)(zhu)品(pin)牌(pai)(pai)發(fa)展,國(guo)(guo)(guo)產汽(qi)(qi)(qi)(qi)車(che)(che)業(ye)的(de)(de)(de)(de)繁榮將為(wei)(wei)汽(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)(de)(de)(de)應用(yong)提(ti)供(gong)有力(li)保(bao)(bao)障。預(yu)測未來3年(nian),我國(guo)(guo)(guo)室溫硫(liu)化硅(gui)橡(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)(qi)車(che)(che)行業(ye)將以(yi)年(nian)均20%增(zeng)長(chang)。
此(ci)外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)是(shi)重(zhong)要的(de)非石(shi)油基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),約(yue)占(zhan)非石(shi)油基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)消費量的(de)98%。但因(yin)為石(shi)油價格的(de)大幅上漲,同時我國在(zai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)關鍵原料有機(ji)硅(gui)單(dan)體的(de)生產(chan)技術(shu)方面取得突破(po),有機(ji)硅(gui)單(dan)體的(de)生產(chan)技術(shu)在(zai)2005年(nian)前被(bei)幾家跨國公司(si)壟斷,但目前我國已(yi)發展成(cheng)(cheng)為全球有機(ji)硅(gui)單(dan)體第1大國,這(zhe)2個方面原因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)價格從2011年(nian)起開(kai)始低于石(shi)油基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),僅約(yue)為大宗石(shi)油基橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為廉價的(de)合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),并開(kai)始大規(gui)模(mo)替(ti)代石(shi)油基合(he)(he)成(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。這(zhe)將極(ji)大拓(tuo)展有機(ji)硅(gui)產(chan)業(ye)的(de)市(shi)場空間,同時將帶動(dong)硅(gui)油、硅(gui)烷(wan)偶聯(lian)劑和(he)硅(gui)樹脂等其他有機(ji)硅(gui)產(chan)品(pin)的(de)消費。