
硅橡膠是(shi)指主鏈由硅(gui)(gui)(gui)和氧原(yuan)子交替(ti)構成,硅(gui)(gui)(gui)原(yuan)子上通常連有兩(liang)個(ge)有機基(ji)(ji)(ji)團的(de)(de)(de)(de)橡(xiang)(xiang)膠(jiao)。普通的(de)(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)(ji)(ji)和少量乙烯(xi)基(ji)(ji)(ji)的(de)(de)(de)(de)硅(gui)(gui)(gui)氧鏈節組成。苯基(ji)(ji)(ji)的(de)(de)(de)(de)引入(ru)可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)耐高(gao)(gao)、低(di)溫(wen)性(xing)(xing)(xing)能,三氟(fu)丙基(ji)(ji)(ji)及氰基(ji)(ji)(ji)的(de)(de)(de)(de)引入(ru)則可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)耐溫(wen)及耐油性(xing)(xing)(xing)能。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)耐低(di)溫(wen)性(xing)(xing)(xing)能良好,一般在(zai)(zai)(zai)-55℃下(xia)仍(reng)能工作。引入(ru)苯基(ji)(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)耐熱性(xing)(xing)(xing)能也(ye)很(hen)突出,在(zai)(zai)(zai)180℃下(xia)可長(chang)(chang)期工作,稍(shao)高(gao)(gao)于(yu)200℃也(ye)能承受數周或更長(chang)(chang)時間仍(reng)有彈性(xing)(xing)(xing),瞬時可耐300℃以上的(de)(de)(de)(de)高(gao)(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)好,氧氣(qi)透過率在(zai)(zai)(zai)合(he)成聚(ju)合(he)物中是(shi)較高(gao)(gao)的(de)(de)(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)還具有生理惰(duo)性(xing)(xing)(xing)、不會(hui)導致(zhi)凝血的(de)(de)(de)(de)突出特性(xing)(xing)(xing),因此在(zai)(zai)(zai)醫用(yong)領(ling)域應用(yong)廣泛(fan)。
主要品種
硅(gui)(gui)橡膠(jiao)分(fen)類的方法很多,通(tong)常按(an)固(gu)化前的形態分(fen)為(wei)固(gu)體硅(gui)(gui)橡膠(jiao)和液體硅(gui)(gui)橡膠(jiao);按(an)硫(liu)化溫(wen)度分(fen)為(wei)室溫(wen)硫(liu)化硅(gui)(gui)橡膠(jiao),高(gao)溫(wen)硫(liu)化硅(gui)(gui)橡膠(jiao);按(an)所用單體的不(bu)同,可(ke)分(fen)為(wei)甲(jia)基(ji)乙烯基(ji)硅(gui)(gui)橡膠(jiao),甲(jia)基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡膠(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡膠(jiao)等;按(an)性能和用途的不(bu)同又可(ke)分(fen)為(wei)通(tong)用型(xing)(xing)、超耐(nai)低溫(wen)型(xing)(xing)、超耐(nai)高(gao)溫(wen)型(xing)(xing)、高(gao)強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由美國(guo)(guo)(guo)以三氯化(hua)鐵為催化(hua)劑(ji)合成的(de)。1945年,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年,采用(yong)高比(bi)表面(mian)積的(de)氣相法白(bai)炭黑補強的(de)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制成功,使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍升(sheng)到(dao)實用(yong)階段,奠(dian)定了現代硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產技術的(de)基(ji)礎(chu)。從二甲(jia)基(ji)二氯硅(gui)(gui)(gui)(gui)(gui)烷(wan)合成開始生(sheng)(sheng)產硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)(guo)(guo)家(jia)有美國(guo)(guo)(guo)。俄(e)羅斯、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)(zhong)國(guo)(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)工業(ye)化(hua)研(yan)究始于1957年,多家(jia)研(yan)究所和企業(ye)陸(lu)續(xu)開發(fa)出各(ge)種硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年底,中(zhong)(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)(sheng)產能(neng)力為135千噸(dun),其中(zhong)(zhong)高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫(wen)硫化(hua)(hua)(hua)(hua)硅(gui)(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)(gui)氧烷(wan)變成(cheng)彈性(xing)體的(de)(de)過(guo)程是(shi)(shi)經過(guo)高溫(wen)(110-170℃)硫化(hua)(hua)(hua)(hua)成(cheng)型(xing)的(de)(de)。它主要以高分子(zi)量(liang)的(de)(de)聚甲(jia)基乙烯(xi)基硅(gui)(gui)氧烷(wan)為生(sheng)膠(jiao)(jiao),混入(ru)補強(qiang)(qiang)填料、硫化(hua)(hua)(hua)(hua)劑等,在加熱加壓下硫化(hua)(hua)(hua)(hua)成(cheng)彈性(xing)體。硅(gui)(gui)橡膠(jiao)(jiao)的(de)(de)補強(qiang)(qiang)主要是(shi)(shi)各(ge)種類型(xing)的(de)(de)白(bai)炭黑,可使(shi)硫化(hua)(hua)(hua)(hua)膠(jiao)(jiao)的(de)(de)強(qiang)(qiang)度增加數十倍。有(you)時為了降低成(cheng)本或改善(shan)膠(jiao)(jiao)料性(xing)能(neng)及賦予硫化(hua)(hua)(hua)(hua)膠(jiao)(jiao)各(ge)種特殊(shu)的(de)(de)性(xing)能(neng),也加入(ru)相應的(de)(de)各(ge)種添加劑。硫化(hua)(hua)(hua)(hua)劑是(shi)(shi)各(ge)種有(you)機過(guo)氧化(hua)(hua)(hua)(hua)物或加成(cheng)反應催化(hua)(hua)(hua)(hua)劑。
加(jia)工成型方法如(ru)圖所示。一次硫(liu)化的(de)(de)(de)目的(de)(de)(de)是進行高分(fen)子鏈的(de)(de)(de)交聯反應;二(er)次硫(liu)化的(de)(de)(de)目的(de)(de)(de)是進行補充交聯、驅(qu)除(chu)硫(liu)化劑分(fen)解產物和其他揮發性(xing)(xing)化合物以(yi)穩定硫(liu)化膠的(de)(de)(de)各項(xiang)性(xing)(xing)能。常(chang)用的(de)(de)(de)設(she)備有開放式煉膠機、捏合機及真空(kong)密(mi)煉機。
主要性能
(1)高(gao)溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的(de)(de)(de)特(te)征是高(gao)溫穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)強(qiang)度僅是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些(xie)合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)一半,但(dan)在200℃以(yi)上的(de)(de)(de)高(gao)溫環境下(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保(bao)持一定(ding)的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無明(ming)(ming)顯(xian)變化。(2)低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)玻璃化溫度一般(ban)為-70~-50℃,特(te)殊配(pei)方可達-100℃,表明(ming)(ming)其低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異。這對(dui)航空、宇航工業的(de)(de)(de)意義(yi)重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭(chou)氧(yang)及(ji)紫外線等十分穩定(ding),在不(bu)加任(ren)何添加劑的(de)(de)(de)情況下(xia)(xia),就具(ju)有(you)(you)優良的(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)(you)優異的(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常好。(5)物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫下(xia)(xia)的(de)(de)(de)物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)高(gao)溫和-50℃的(de)(de)(de)低溫下(xia)(xia),其物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐油及(ji)化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)(you)中等的(de)(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室(shi)溫下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)空氣、氮、氧(yang)、二氧(yang)化碳等氣體的(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無毒,無味,無嗅,與人體組織(zhi)不(bu)粘連,具(ju)有(you)(you)抗凝血作用,對(dui)肌體組織(zhi)的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作為醫用材料。
硅橡膠的用量
據中(zhong)國汽(qi)(qi)車(che)(che)工(gong)業(ye)協會統計,2012年,汽(qi)(qi)車(che)(che)產(chan)銷分(fen)別達到1927.18萬(wan)輛(liang)和(he)1930.64萬(wan)輛(liang),同比分(fen)別增長4.63%和(he)4.33%,汽(qi)(qi)車(che)(che)工(gong)業(ye)硅(gui)橡(xiang)(xiang)膠的(de)(de)用量(liang)(liang)約達2.0萬(wan)t。根據觀研天下的(de)(de)新研究(jiu),增加有(you)機硅(gui)材料在(zai)汽(qi)(qi)車(che)(che)零(ling)部(bu)件方面(mian)的(de)(de)用量(liang)(liang),可以(yi)大(da)幅度提高汽(qi)(qi)車(che)(che)的(de)(de)安全性能,因此,汽(qi)(qi)車(che)(che)產(chan)量(liang)(liang)和(he)單車(che)(che)用量(liang)(liang)水平的(de)(de)提高都(dou)將(jiang)(jiang)推動汽(qi)(qi)車(che)(che)工(gong)業(ye)對硅(gui)橡(xiang)(xiang)膠需(xu)求(qiu)的(de)(de)增加。國家(jia)鼓勵自(zi)主(zhu)品(pin)牌的(de)(de)汽(qi)(qi)車(che)(che)發(fa)(fa)展,關鍵(jian)汽(qi)(qi)車(che)(che)零(ling)部(bu)件實(shi)現自(zi)主(zhu)化,《2012年度黨政(zheng)機關公務用車(che)(che)選用車(che)(che)型目錄(征(zheng)求(qiu)意見稿)》為(wei)自(zi)主(zhu)品(pin)牌擴大(da)在(zai)政(zheng)府采購(gou)的(de)(de)市場份額,為(wei)改(gai)變目前國內政(zheng)府采購(gou)以(yi)合資品(pin)牌產(chan)品(pin)為(wei)主(zhu)的(de)(de)局(ju)面(mian)提供了保(bao)障。促(cu)進自(zi)主(zhu)品(pin)牌發(fa)(fa)展,國產(chan)汽(qi)(qi)車(che)(che)業(ye)的(de)(de)繁(fan)榮將(jiang)(jiang)為(wei)汽(qi)(qi)車(che)(che)膠的(de)(de)應用提供有(you)力保(bao)障。預測(ce)未來(lai)3年,我國室溫硫化硅(gui)橡(xiang)(xiang)膠在(zai)汽(qi)(qi)車(che)(che)行(xing)業(ye)將(jiang)(jiang)以(yi)年均(jun)20%增長。
此外(wai),硅橡(xiang)膠(jiao)(jiao)是重(zhong)要的非石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),約(yue)占(zhan)非石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)消費量的98%。但因為(wei)石(shi)(shi)(shi)油(you)(you)價(jia)(jia)格的大(da)幅上漲,同時我國在硅橡(xiang)膠(jiao)(jiao)的關(guan)鍵原料有(you)機硅單體的生(sheng)產技(ji)術方(fang)面(mian)取得突破,有(you)機硅單體的生(sheng)產技(ji)術在2005年(nian)前被幾(ji)家跨國公司壟斷,但目前我國已(yi)發展成(cheng)為(wei)全(quan)球有(you)機硅單體第1大(da)國,這2個方(fang)面(mian)原因使硅橡(xiang)膠(jiao)(jiao)的價(jia)(jia)格從(cong)2011年(nian)起開(kai)始低于石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),僅(jin)約(yue)為(wei)大(da)宗石(shi)(shi)(shi)油(you)(you)基(ji)橡(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)為(wei)廉價(jia)(jia)的合(he)成(cheng)橡(xiang)膠(jiao)(jiao),并(bing)開(kai)始大(da)規(gui)模替代石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)。這將極大(da)拓展有(you)機硅產業(ye)的市(shi)場空(kong)間(jian),同時將帶動硅油(you)(you)、硅烷偶聯(lian)劑和硅樹脂等其他有(you)機硅產品的消費。