
硅橡膠是(shi)指主(zhu)鏈(lian)由硅(gui)和(he)氧(yang)原(yuan)子交替構成(cheng),硅(gui)原(yuan)子上通(tong)常連有兩個有機(ji)基(ji)(ji)團的(de)(de)(de)(de)橡膠(jiao)。普(pu)通(tong)的(de)(de)(de)(de)硅(gui)橡膠(jiao)主(zhu)要由含甲(jia)基(ji)(ji)和(he)少量(liang)乙烯基(ji)(ji)的(de)(de)(de)(de)硅(gui)氧(yang)鏈(lian)節組成(cheng)。苯(ben)基(ji)(ji)的(de)(de)(de)(de)引(yin)(yin)入可(ke)提高(gao)(gao)硅(gui)橡膠(jiao)的(de)(de)(de)(de)耐(nai)高(gao)(gao)、低(di)溫(wen)(wen)(wen)性(xing)(xing)能(neng)(neng),三(san)氟丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)(de)引(yin)(yin)入則可(ke)提高(gao)(gao)硅(gui)橡膠(jiao)的(de)(de)(de)(de)耐(nai)溫(wen)(wen)(wen)及耐(nai)油性(xing)(xing)能(neng)(neng)。硅(gui)橡膠(jiao)耐(nai)低(di)溫(wen)(wen)(wen)性(xing)(xing)能(neng)(neng)良好,一(yi)般在-55℃下仍能(neng)(neng)工作。引(yin)(yin)入苯(ben)基(ji)(ji)后,可(ke)達(da)-73℃。硅(gui)橡膠(jiao)的(de)(de)(de)(de)耐(nai)熱(re)性(xing)(xing)能(neng)(neng)也(ye)(ye)很突出,在180℃下可(ke)長(chang)期工作,稍高(gao)(gao)于200℃也(ye)(ye)能(neng)(neng)承受數周或更長(chang)時間(jian)仍有彈性(xing)(xing),瞬時可(ke)耐(nai)300℃以(yi)上的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)。硅(gui)橡膠(jiao)的(de)(de)(de)(de)透氣(qi)性(xing)(xing)好,氧(yang)氣(qi)透過率(lv)在合(he)成(cheng)聚合(he)物中是(shi)較高(gao)(gao)的(de)(de)(de)(de)。此外,硅(gui)橡膠(jiao)還具有生理惰性(xing)(xing)、不會導致凝血的(de)(de)(de)(de)突出特(te)性(xing)(xing),因(yin)此在醫用領域應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分類的方法(fa)很多(duo),通常按(an)(an)固化前的形態分為(wei)(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)硫(liu)化溫(wen)度分為(wei)(wei)室溫(wen)硫(liu)化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)(gao)溫(wen)硫(liu)化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)(an)所用單體的不同,可(ke)分為(wei)(wei)甲基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈(jing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)(an)性能和用途的不同又(you)可(ke)分為(wei)(wei)通用型、超(chao)耐低溫(wen)型、超(chao)耐高(gao)(gao)溫(wen)型、高(gao)(gao)強(qiang)力型、耐油型、醫用型等等。
發展史
硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)早期是由美(mei)國(guo)以(yi)三氯(lv)化(hua)鐵為催(cui)化(hua)劑合(he)成(cheng)的(de)(de)。1945年,硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)產(chan)(chan)品問(wen)世。1948年,采用高比表面(mian)積的(de)(de)氣相法白炭黑補強的(de)(de)硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)研(yan)(yan)制成(cheng)功,使硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)性能(neng)躍升到(dao)實用階段,奠定了現(xian)代硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)(chan)技術的(de)(de)基礎。從二甲基二氯(lv)硅(gui)(gui)(gui)烷合(he)成(cheng)開始生產(chan)(chan)硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)國(guo)家(jia)有美(mei)國(guo)。俄羅斯、德國(guo)、日本、韓(han)國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)的(de)(de)工業化(hua)研(yan)(yan)究(jiu)始于1957年,多(duo)家(jia)研(yan)(yan)究(jiu)所和(he)企(qi)業陸續開發出各種硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)。到(dao)2003年底(di),中(zhong)國(guo)硅(gui)(gui)(gui)橡膠(jiao)(jiao)(jiao)(jiao)生產(chan)(chan)能(neng)力為135千(qian)噸,其(qi)中(zhong)高溫膠(jiao)(jiao)(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)膠(jiao)是指聚硅(gui)(gui)氧烷(wan)變成(cheng)(cheng)(cheng)彈性體的(de)(de)(de)(de)(de)過程是經過高(gao)溫(wen)(110-170℃)硫(liu)化(hua)(hua)成(cheng)(cheng)(cheng)型的(de)(de)(de)(de)(de)。它主要以(yi)高(gao)分子量的(de)(de)(de)(de)(de)聚甲基乙烯基硅(gui)(gui)氧烷(wan)為(wei)生膠(jiao),混入補強填料、硫(liu)化(hua)(hua)劑等,在(zai)加熱加壓(ya)下硫(liu)化(hua)(hua)成(cheng)(cheng)(cheng)彈性體。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)(de)補強主要是各種類(lei)型的(de)(de)(de)(de)(de)白炭黑,可使硫(liu)化(hua)(hua)膠(jiao)的(de)(de)(de)(de)(de)強度(du)增加數十倍。有時為(wei)了降低成(cheng)(cheng)(cheng)本或(huo)改善膠(jiao)料性能及(ji)賦予(yu)硫(liu)化(hua)(hua)膠(jiao)各種特殊的(de)(de)(de)(de)(de)性能,也加入相(xiang)應的(de)(de)(de)(de)(de)各種添(tian)加劑。硫(liu)化(hua)(hua)劑是各種有機過氧化(hua)(hua)物或(huo)加成(cheng)(cheng)(cheng)反應催化(hua)(hua)劑。
加工成型(xing)方法如(ru)圖所示。一次硫化(hua)的(de)(de)目(mu)的(de)(de)是(shi)進(jin)行高分(fen)(fen)子鏈的(de)(de)交聯反應;二次硫化(hua)的(de)(de)目(mu)的(de)(de)是(shi)進(jin)行補充交聯、驅除(chu)硫化(hua)劑分(fen)(fen)解產(chan)物和其(qi)他揮發性(xing)化(hua)合物以穩(wen)定硫化(hua)膠的(de)(de)各(ge)項性(xing)能。常用的(de)(de)設備(bei)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)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)(xian)著的(de)特(te)征是高(gao)溫(wen)(wen)(wen)(wen)(wen)穩(wen)(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)強(qiang)度僅是天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)一半,但在200℃以(yi)上的(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)環境下(xia),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持(chi)一定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無明顯(xian)(xian)變化(hua)(hua)。(2)低(di)(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)玻璃化(hua)(hua)溫(wen)(wen)(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方可達-100℃,表明其(qi)低(di)(di)溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異(yi)。這對航(hang)空、宇航(hang)工業(ye)的(de)意義重大。(3)耐(nai)候(hou)(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及紫外線等十分穩(wen)(wen)定,在不加(jia)任何添加(jia)劑(ji)的(de)情(qing)況(kuang)下(xia),就具有(you)優良(liang)的(de)耐(nai)候(hou)(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)優異(yi)的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下(xia)的(de)物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)和-50℃的(de)低(di)(di)溫(wen)(wen)(wen)(wen)(wen)下(xia),其(qi)物(wu)理(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及化(hua)(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)中等的(de)耐(nai)油(you)、耐(nai)溶(rong)劑(ji)性(xing)(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)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣、氮、氧(yang)、二氧(yang)化(hua)(hua)碳等氣體的(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人體組(zu)織不粘(zhan)連,具有(you)抗凝(ning)血作(zuo)用(yong),對肌體組(zu)織的(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特(te)別適合(he)作(zuo)為醫用(yong)材料。
硅橡膠的用量
據(ju)中國汽(qi)車(che)(che)工業(ye)協會統(tong)計,2012年,汽(qi)車(che)(che)產(chan)(chan)銷分別達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分別增(zeng)(zeng)長4.63%和4.33%,汽(qi)車(che)(che)工業(ye)硅(gui)(gui)橡膠(jiao)的(de)用(yong)(yong)量約達2.0萬t。根據(ju)觀(guan)研(yan)(yan)天下的(de)新研(yan)(yan)究,增(zeng)(zeng)加有機(ji)硅(gui)(gui)材料在(zai)汽(qi)車(che)(che)零部件方面(mian)的(de)用(yong)(yong)量,可以(yi)大(da)幅度提(ti)(ti)(ti)高汽(qi)車(che)(che)的(de)安(an)全性能,因此,汽(qi)車(che)(che)產(chan)(chan)量和單(dan)車(che)(che)用(yong)(yong)量水平的(de)提(ti)(ti)(ti)高都將(jiang)推(tui)動(dong)汽(qi)車(che)(che)工業(ye)對硅(gui)(gui)橡膠(jiao)需(xu)求(qiu)的(de)增(zeng)(zeng)加。國家鼓勵自(zi)主(zhu)(zhu)品(pin)牌的(de)汽(qi)車(che)(che)發展,關鍵(jian)汽(qi)車(che)(che)零部件實(shi)現自(zi)主(zhu)(zhu)化(hua),《2012年度黨政(zheng)機(ji)關公務用(yong)(yong)車(che)(che)選用(yong)(yong)車(che)(che)型目錄(征求(qiu)意(yi)見稿(gao))》為(wei)(wei)自(zi)主(zhu)(zhu)品(pin)牌擴(kuo)大(da)在(zai)政(zheng)府采(cai)購的(de)市(shi)場(chang)份額,為(wei)(wei)改變目前國內政(zheng)府采(cai)購以(yi)合資品(pin)牌產(chan)(chan)品(pin)為(wei)(wei)主(zhu)(zhu)的(de)局面(mian)提(ti)(ti)(ti)供了保障。促進自(zi)主(zhu)(zhu)品(pin)牌發展,國產(chan)(chan)汽(qi)車(che)(che)業(ye)的(de)繁榮將(jiang)為(wei)(wei)汽(qi)車(che)(che)膠(jiao)的(de)應用(yong)(yong)提(ti)(ti)(ti)供有力保障。預(yu)測(ce)未來3年,我國室溫(wen)硫化(hua)硅(gui)(gui)橡膠(jiao)在(zai)汽(qi)車(che)(che)行業(ye)將(jiang)以(yi)年均20%增(zeng)(zeng)長。
此(ci)外,硅(gui)橡膠(jiao)(jiao)是重要的(de)非(fei)石(shi)油基合成(cheng)(cheng)橡膠(jiao)(jiao),約占非(fei)石(shi)油基合成(cheng)(cheng)橡膠(jiao)(jiao)消(xiao)費(fei)量(liang)的(de)98%。但因為石(shi)油價(jia)格(ge)的(de)大幅上(shang)漲(zhang),同時(shi)我(wo)(wo)國(guo)在(zai)硅(gui)橡膠(jiao)(jiao)的(de)關鍵原料(liao)有(you)機(ji)硅(gui)單(dan)體(ti)的(de)生(sheng)(sheng)產(chan)(chan)(chan)技術方面(mian)取(qu)得突(tu)破,有(you)機(ji)硅(gui)單(dan)體(ti)的(de)生(sheng)(sheng)產(chan)(chan)(chan)技術在(zai)2005年(nian)前被幾家跨國(guo)公司壟斷,但目前我(wo)(wo)國(guo)已發展成(cheng)(cheng)為全球有(you)機(ji)硅(gui)單(dan)體(ti)第1大國(guo),這2個方面(mian)原因使硅(gui)橡膠(jiao)(jiao)的(de)價(jia)格(ge)從(cong)2011年(nian)起開始低于石(shi)油基合成(cheng)(cheng)橡膠(jiao)(jiao),僅約為大宗石(shi)油基橡膠(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為廉價(jia)的(de)合成(cheng)(cheng)橡膠(jiao)(jiao),并開始大規模替代石(shi)油基合成(cheng)(cheng)橡膠(jiao)(jiao)。這將極大拓展有(you)機(ji)硅(gui)產(chan)(chan)(chan)業的(de)市(shi)場空間,同時(shi)將帶動硅(gui)油、硅(gui)烷偶聯劑和硅(gui)樹脂等其他有(you)機(ji)硅(gui)產(chan)(chan)(chan)品的(de)消(xiao)費(fei)。