硅橡膠是指主鏈由硅(gui)和氧(yang)原子交替構成(cheng),硅(gui)原子上通(tong)(tong)常連(lian)有(you)兩個有(you)機基團的(de)(de)(de)(de)橡(xiang)膠(jiao)(jiao)(jiao)。普通(tong)(tong)的(de)(de)(de)(de)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)主要由含(han)甲(jia)基和少量(liang)乙烯(xi)基的(de)(de)(de)(de)硅(gui)氧(yang)鏈節組成(cheng)。苯基的(de)(de)(de)(de)引入可提(ti)(ti)高(gao)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐(nai)高(gao)、低溫性(xing)能(neng)(neng),三(san)氟丙基及(ji)氰基的(de)(de)(de)(de)引入則可提(ti)(ti)高(gao)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐(nai)溫及(ji)耐(nai)油性(xing)能(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)耐(nai)低溫性(xing)能(neng)(neng)良好(hao),一般(ban)在(zai)-55℃下(xia)仍能(neng)(neng)工作(zuo)。引入苯基后,可達(da)-73℃。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)耐(nai)熱性(xing)能(neng)(neng)也(ye)很突出,在(zai)180℃下(xia)可長期工作(zuo),稍高(gao)于200℃也(ye)能(neng)(neng)承受數周或(huo)更長時間仍有(you)彈(dan)性(xing),瞬時可耐(nai)300℃以上的(de)(de)(de)(de)高(gao)溫。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)透氣(qi)性(xing)好(hao),氧(yang)氣(qi)透過率在(zai)合成(cheng)聚合物中是較(jiao)高(gao)的(de)(de)(de)(de)。此(ci)外(wai),硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)還具有(you)生理惰性(xing)、不會(hui)導致凝血的(de)(de)(de)(de)突出特性(xing),因此(ci)在(zai)醫用領域應用廣泛。
主要品種
硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)分(fen)類的(de)(de)方法很多,通常按固化前(qian)的(de)(de)形態分(fen)為固體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)和液(ye)體硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按硫化溫度分(fen)為室(shi)溫硫化硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),高(gao)(gao)溫硫化硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按所用單體的(de)(de)不(bu)(bu)同,可(ke)分(fen)為甲(jia)基乙烯基硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲(jia)基苯基乙烯基硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui)(gui),腈硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)等;按性能和用途的(de)(de)不(bu)(bu)同又可(ke)分(fen)為通用型(xing)、超耐低溫型(xing)、超耐高(gao)(gao)溫型(xing)、高(gao)(gao)強力型(xing)、耐油型(xing)、醫用型(xing)等等。
發展史
硅(gui)(gui)橡膠(jiao)(jiao)早(zao)期是由美國(guo)以(yi)三氯(lv)化鐵為(wei)催化劑合(he)成(cheng)的(de)。1945年(nian)(nian)(nian),硅(gui)(gui)橡膠(jiao)(jiao)產品問(wen)世。1948年(nian)(nian)(nian),采(cai)用高(gao)(gao)比表(biao)面積的(de)氣相法白(bai)炭(tan)黑(hei)補(bu)強的(de)硅(gui)(gui)橡膠(jiao)(jiao)研制成(cheng)功,使硅(gui)(gui)橡膠(jiao)(jiao)的(de)性能躍升到(dao)實用階段,奠定了(le)現代硅(gui)(gui)橡膠(jiao)(jiao)生產技術的(de)基(ji)(ji)礎。從二甲(jia)基(ji)(ji)二氯(lv)硅(gui)(gui)烷合(he)成(cheng)開始生產硅(gui)(gui)橡膠(jiao)(jiao)的(de)國(guo)家(jia)有美國(guo)。俄(e)羅斯、德國(guo)、日本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)橡膠(jiao)(jiao)的(de)工業化研究始于1957年(nian)(nian)(nian),多家(jia)研究所和企業陸續開發出(chu)各種硅(gui)(gui)橡膠(jiao)(jiao)。到(dao)2003年(nian)(nian)(nian)底(di),中國(guo)硅(gui)(gui)橡膠(jiao)(jiao)生產能力為(wei)135千(qian)噸,其中高(gao)(gao)溫膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫(wen)硫(liu)化(hua)(hua)(hua)硅橡膠(jiao)(jiao)是指聚(ju)硅氧烷變(bian)成(cheng)彈性體(ti)的(de)過(guo)(guo)程(cheng)是經過(guo)(guo)高溫(wen)(110-170℃)硫(liu)化(hua)(hua)(hua)成(cheng)型(xing)的(de)。它主要(yao)以(yi)高分(fen)子(zi)量(liang)的(de)聚(ju)甲基乙烯基硅氧烷為生膠(jiao)(jiao),混入補強填料、硫(liu)化(hua)(hua)(hua)劑(ji)等,在加(jia)熱加(jia)壓(ya)下硫(liu)化(hua)(hua)(hua)成(cheng)彈性體(ti)。硅橡膠(jiao)(jiao)的(de)補強主要(yao)是各種類型(xing)的(de)白炭黑,可使(shi)硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的(de)強度增加(jia)數十倍。有時(shi)為了降低成(cheng)本或改善膠(jiao)(jiao)料性能(neng)及(ji)賦予硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各種特殊的(de)性能(neng),也加(jia)入相應(ying)的(de)各種添加(jia)劑(ji)。硫(liu)化(hua)(hua)(hua)劑(ji)是各種有機過(guo)(guo)氧化(hua)(hua)(hua)物或加(jia)成(cheng)反應(ying)催化(hua)(hua)(hua)劑(ji)。
加工成型方法如圖所示(shi)。一次硫(liu)化(hua)(hua)的(de)目的(de)是(shi)進(jin)行(xing)(xing)高分(fen)子鏈的(de)交(jiao)聯反應;二次硫(liu)化(hua)(hua)的(de)目的(de)是(shi)進(jin)行(xing)(xing)補充交(jiao)聯、驅除硫(liu)化(hua)(hua)劑分(fen)解(jie)產物和其他揮發性化(hua)(hua)合物以穩定硫(liu)化(hua)(hua)膠的(de)各項性能。常(chang)用的(de)設備有開放(fang)式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然(ran)(ran)(ran)常(chang)溫(wen)(wen)(wen)下(xia)(xia)(xia)(xia)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)僅是(shi)天然(ran)(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia)(xia)(xia)(xia),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表(biao)面硬(ying)度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明顯變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)(wen)度(du)一(yi)般為-70~-50℃,特(te)殊配方可達-100℃,表(biao)明其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異(yi)。這對航(hang)空(kong)、宇航(hang)工業的(de)(de)(de)(de)(de)意(yi)義重大。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)紫外線(xian)等十(shi)分(fen)穩定(ding),在不加任(ren)何添加劑的(de)(de)(de)(de)(de)情況下(xia)(xia)(xia)(xia),就具(ju)有(you)(you)優良的(de)(de)(de)(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)優異(yi)的(de)(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)(xia)(xia)(xia)的(de)(de)(de)(de)(de)物(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)和(he)(he)-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)(wen)下(xia)(xia)(xia)(xia),其物(wu)理(li)機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通用橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)(you)中等的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)(xia)(xia)(xia)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)對空(kong)氣(qi)、氮、氧(yang)、二氧(yang)化碳等氣(qi)體(ti)的(de)(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)(ran)(ran)橡(xiang)膠(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人體(ti)組織不粘連,具(ju)有(you)(you)抗凝(ning)血作用,對肌體(ti)組織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)別適合(he)作為醫(yi)用材料。
硅橡膠的用量
據(ju)中(zhong)國(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)輛和1930.64萬(wan)輛,同比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)工業硅橡膠(jiao)(jiao)的(de)(de)(de)(de)用量(liang)約(yue)達2.0萬(wan)t。根據(ju)觀研(yan)天下的(de)(de)(de)(de)新研(yan)究(jiu),增(zeng)加(jia)有機硅材料在(zai)汽(qi)(qi)(qi)(qi)車(che)零部(bu)件方(fang)面的(de)(de)(de)(de)用量(liang),可(ke)以大(da)幅度提(ti)(ti)高汽(qi)(qi)(qi)(qi)車(che)的(de)(de)(de)(de)安全性能(neng),因此,汽(qi)(qi)(qi)(qi)車(che)產量(liang)和單車(che)用量(liang)水平的(de)(de)(de)(de)提(ti)(ti)高都將(jiang)推動汽(qi)(qi)(qi)(qi)車(che)工業對(dui)硅橡膠(jiao)(jiao)需求的(de)(de)(de)(de)增(zeng)加(jia)。國(guo)家鼓勵自(zi)(zi)主(zhu)(zhu)(zhu)品(pin)牌的(de)(de)(de)(de)汽(qi)(qi)(qi)(qi)車(che)發展,關鍵(jian)汽(qi)(qi)(qi)(qi)車(che)零部(bu)件實現(xian)自(zi)(zi)主(zhu)(zhu)(zhu)化,《2012年度黨政機關公務用車(che)選用車(che)型(xing)目(mu)錄(征求意見(jian)稿(gao))》為(wei)(wei)自(zi)(zi)主(zhu)(zhu)(zhu)品(pin)牌擴大(da)在(zai)政府(fu)采購(gou)的(de)(de)(de)(de)市(shi)場份額,為(wei)(wei)改變目(mu)前國(guo)內政府(fu)采購(gou)以合資品(pin)牌產品(pin)為(wei)(wei)主(zhu)(zhu)(zhu)的(de)(de)(de)(de)局面提(ti)(ti)供(gong)了保(bao)障。促(cu)進(jin)自(zi)(zi)主(zhu)(zhu)(zhu)品(pin)牌發展,國(guo)產汽(qi)(qi)(qi)(qi)車(che)業的(de)(de)(de)(de)繁榮將(jiang)為(wei)(wei)汽(qi)(qi)(qi)(qi)車(che)膠(jiao)(jiao)的(de)(de)(de)(de)應用提(ti)(ti)供(gong)有力保(bao)障。預測(ce)未來3年,我國(guo)室溫硫化硅橡膠(jiao)(jiao)在(zai)汽(qi)(qi)(qi)(qi)車(che)行業將(jiang)以年均20%增(zeng)長。
此外,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠是重(zhong)要的(de)(de)非石(shi)油(you)(you)基合(he)成(cheng)(cheng)(cheng)橡(xiang)膠,約(yue)占非石(shi)油(you)(you)基合(he)成(cheng)(cheng)(cheng)橡(xiang)膠消費量(liang)的(de)(de)98%。但(dan)因為(wei)石(shi)油(you)(you)價(jia)格(ge)的(de)(de)大幅(fu)上漲,同(tong)時(shi)我(wo)國(guo)(guo)在硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的(de)(de)關鍵原(yuan)料(liao)有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)的(de)(de)生(sheng)產(chan)(chan)(chan)(chan)技術(shu)方面(mian)取得突破,有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)的(de)(de)生(sheng)產(chan)(chan)(chan)(chan)技術(shu)在2005年(nian)前被(bei)幾(ji)家(jia)跨(kua)國(guo)(guo)公司壟斷,但(dan)目(mu)前我(wo)國(guo)(guo)已(yi)發展成(cheng)(cheng)(cheng)為(wei)全球有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單(dan)體(ti)(ti)第1大國(guo)(guo),這2個方面(mian)原(yuan)因使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)膠的(de)(de)價(jia)格(ge)從2011年(nian)起開始低于石(shi)油(you)(you)基合(he)成(cheng)(cheng)(cheng)橡(xiang)膠,僅約(yue)為(wei)大宗石(shi)油(you)(you)基橡(xiang)膠的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉(lian)價(jia)的(de)(de)合(he)成(cheng)(cheng)(cheng)橡(xiang)膠,并開始大規(gui)模替(ti)代石(shi)油(you)(you)基合(he)成(cheng)(cheng)(cheng)橡(xiang)膠。這將極(ji)大拓(tuo)展有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)(chan)(chan)(chan)業的(de)(de)市場空間,同(tong)時(shi)將帶動硅(gui)(gui)(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)(gui)(gui)(gui)樹脂等其(qi)他有(you)(you)機(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)產(chan)(chan)(chan)(chan)品(pin)的(de)(de)消費。