硅橡膠是(shi)指主(zhu)鏈由硅(gui)和氧(yang)原(yuan)子交替構成,硅(gui)原(yuan)子上通(tong)常連有兩個有機基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)(xiang)膠。普通(tong)的(de)(de)(de)硅(gui)橡(xiang)(xiang)(xiang)膠主(zhu)要由含(han)甲基(ji)(ji)和少量(liang)乙烯基(ji)(ji)的(de)(de)(de)硅(gui)氧(yang)鏈節組成。苯基(ji)(ji)的(de)(de)(de)引(yin)入可(ke)(ke)(ke)提(ti)高(gao)(gao)硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)高(gao)(gao)、低溫性(xing)能,三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引(yin)入則可(ke)(ke)(ke)提(ti)高(gao)(gao)硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)溫及耐(nai)油性(xing)能。硅(gui)橡(xiang)(xiang)(xiang)膠耐(nai)低溫性(xing)能良好,一般在-55℃下仍(reng)能工作。引(yin)入苯基(ji)(ji)后,可(ke)(ke)(ke)達-73℃。硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)熱性(xing)能也很突(tu)出,在180℃下可(ke)(ke)(ke)長(chang)(chang)期工作,稍高(gao)(gao)于(yu)200℃也能承受(shou)數周或(huo)更(geng)長(chang)(chang)時間仍(reng)有彈性(xing),瞬(shun)時可(ke)(ke)(ke)耐(nai)300℃以上的(de)(de)(de)高(gao)(gao)溫。硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)透(tou)氣(qi)性(xing)好,氧(yang)氣(qi)透(tou)過率在合成聚合物中是(shi)較高(gao)(gao)的(de)(de)(de)。此(ci)外,硅(gui)橡(xiang)(xiang)(xiang)膠還具有生理(li)惰性(xing)、不會導(dao)致凝血的(de)(de)(de)突(tu)出特(te)性(xing),因此(ci)在醫用領域應(ying)用廣(guang)泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)分類(lei)的方法很多(duo),通常按固化前的形(xing)態(tai)分為(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)和(he)液(ye)體硅(gui)橡(xiang)(xiang)膠(jiao)(jiao);按硫化溫度分為(wei)室溫硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao),高溫硫化硅(gui)橡(xiang)(xiang)膠(jiao)(jiao);按所用(yong)單體的不同,可分為(wei)甲基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲基(ji)苯(ben)基(ji)乙烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)等(deng);按性能(neng)和(he)用(yong)途的不同又(you)可分為(wei)通用(yong)型(xing)(xing)、超耐低(di)溫型(xing)(xing)、超耐高溫型(xing)(xing)、高強力(li)型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅橡膠(jiao)(jiao)早期是由美國以三氯化(hua)鐵為(wei)催化(hua)劑合成的。1945年(nian),硅橡膠(jiao)(jiao)產(chan)(chan)品問世。1948年(nian),采用(yong)高比表面積的氣相法白炭黑補強的硅橡膠(jiao)(jiao)研制成功,使硅橡膠(jiao)(jiao)的性能(neng)(neng)躍升到實(shi)用(yong)階段,奠(dian)定(ding)了現代硅橡膠(jiao)(jiao)生(sheng)產(chan)(chan)技術(shu)的基(ji)礎。從二甲基(ji)二氯硅烷(wan)合成開始生(sheng)產(chan)(chan)硅橡膠(jiao)(jiao)的國家(jia)有美國。俄羅斯、德國、日本(ben)、韓國和中國等。中國硅橡膠(jiao)(jiao)的工業(ye)化(hua)研究始于1957年(nian),多(duo)家(jia)研究所和企業(ye)陸續開發出(chu)各(ge)種硅橡膠(jiao)(jiao)。到2003年(nian)底,中國硅橡膠(jiao)(jiao)生(sheng)產(chan)(chan)能(neng)(neng)力為(wei)135千(qian)噸,其中高溫膠(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)(gao)溫(wen)硫(liu)(liu)(liu)化(hua)(hua)硅(gui)(gui)橡膠是指(zhi)聚(ju)硅(gui)(gui)氧烷變成(cheng)(cheng)彈(dan)性(xing)(xing)(xing)體的過程是經過高(gao)(gao)溫(wen)(110-170℃)硫(liu)(liu)(liu)化(hua)(hua)成(cheng)(cheng)型(xing)(xing)的。它主要(yao)以高(gao)(gao)分子(zi)量的聚(ju)甲基乙烯基硅(gui)(gui)氧烷為(wei)生膠,混(hun)入補強填料(liao)、硫(liu)(liu)(liu)化(hua)(hua)劑(ji)等,在加(jia)熱(re)加(jia)壓下硫(liu)(liu)(liu)化(hua)(hua)成(cheng)(cheng)彈(dan)性(xing)(xing)(xing)體。硅(gui)(gui)橡膠的補強主要(yao)是各(ge)(ge)種(zhong)(zhong)(zhong)類型(xing)(xing)的白炭黑,可使(shi)硫(liu)(liu)(liu)化(hua)(hua)膠的強度增(zeng)加(jia)數(shu)十倍。有時為(wei)了降低(di)成(cheng)(cheng)本或改(gai)善膠料(liao)性(xing)(xing)(xing)能及(ji)賦予硫(liu)(liu)(liu)化(hua)(hua)膠各(ge)(ge)種(zhong)(zhong)(zhong)特殊的性(xing)(xing)(xing)能,也加(jia)入相應的各(ge)(ge)種(zhong)(zhong)(zhong)添加(jia)劑(ji)。硫(liu)(liu)(liu)化(hua)(hua)劑(ji)是各(ge)(ge)種(zhong)(zhong)(zhong)有機過氧化(hua)(hua)物或加(jia)成(cheng)(cheng)反應催化(hua)(hua)劑(ji)。
加(jia)工成型(xing)方法如圖所示(shi)。一次(ci)硫化(hua)(hua)的(de)目(mu)的(de)是進行高分(fen)子鏈(lian)的(de)交聯反應;二次(ci)硫化(hua)(hua)的(de)目(mu)的(de)是進行補充(chong)交聯、驅除(chu)硫化(hua)(hua)劑分(fen)解產(chan)物(wu)和其(qi)他(ta)揮發性(xing)(xing)化(hua)(hua)合物(wu)以穩定硫化(hua)(hua)膠的(de)各項性(xing)(xing)能(neng)。常用的(de)設(she)備有開放式(shi)煉(lian)膠機、捏合機及真空密煉(lian)機。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯著(zhu)的(de)(de)特(te)征是高溫(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)下(xia)(xia)(xia)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)強度僅是天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)一半,但在200℃以上的(de)(de)高溫(wen)(wen)環境下(xia)(xia)(xia),硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)(neng)保持一定的(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)(wu)明顯變(bian)化(hua)。(2)低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)玻璃化(hua)溫(wen)(wen)度一般(ban)為-70~-50℃,特(te)殊配方可達-100℃,表明其低溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)(you)異。這對(dui)(dui)航空、宇航工(gong)業(ye)的(de)(de)意義(yi)重(zhong)大。(3)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中(zhong)Si-O-Si鍵(jian)對(dui)(dui)氧、臭氧及紫外(wai)線等(deng)十分穩(wen)定,在不加任(ren)何添加劑的(de)(de)情況下(xia)(xia)(xia),就具(ju)有(you)優(you)(you)良(liang)的(de)(de)耐(nai)(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)優(you)(you)異的(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)(nai)(nai)電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)下(xia)(xia)(xia)的(de)(de)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比通(tong)(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在150℃的(de)(de)高溫(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)下(xia)(xia)(xia),其物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優(you)(you)于通(tong)(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)(nai)(nai)油(you)及化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)(tong)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)中(zhong)等(deng)的(de)(de)耐(nai)(nai)(nai)(nai)油(you)、耐(nai)(nai)(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)(xia)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)(qi)、氮(dan)、氧、二氧化(hua)碳(tan)等(deng)氣(qi)(qi)(qi)體(ti)(ti)的(de)(de)透(tou)氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高出30-50倍(bei)。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味(wei),無(wu)(wu)嗅,與人體(ti)(ti)組織(zhi)不粘連,具(ju)有(you)抗(kang)凝血作(zuo)用(yong),對(dui)(dui)肌體(ti)(ti)組織(zhi)的(de)(de)反(fan)應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作(zuo)為醫用(yong)材料。
硅橡膠的用量
據(ju)中國汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)協會統計,2012年,汽(qi)(qi)(qi)(qi)車(che)(che)產銷分(fen)別(bie)達到1927.18萬(wan)輛和(he)(he)1930.64萬(wan)輛,同比(bi)分(fen)別(bie)增(zeng)長4.63%和(he)(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)用(yong)量(liang)約達2.0萬(wan)t。根據(ju)觀研天下的(de)(de)新研究,增(zeng)加(jia)有機硅(gui)(gui)材料在汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)部件(jian)方面(mian)的(de)(de)用(yong)量(liang),可以(yi)大幅度提(ti)高(gao)(gao)汽(qi)(qi)(qi)(qi)車(che)(che)的(de)(de)安全性(xing)能,因此(ci),汽(qi)(qi)(qi)(qi)車(che)(che)產量(liang)和(he)(he)單車(che)(che)用(yong)量(liang)水(shui)平的(de)(de)提(ti)高(gao)(gao)都將推(tui)動汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)(ye)(ye)對硅(gui)(gui)橡(xiang)膠(jiao)(jiao)需求的(de)(de)增(zeng)加(jia)。國家鼓勵自主(zhu)(zhu)品(pin)(pin)牌(pai)(pai)的(de)(de)汽(qi)(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)部件(jian)實現自主(zhu)(zhu)化,《2012年度黨政(zheng)機關公(gong)務用(yong)車(che)(che)選(xuan)用(yong)車(che)(che)型目錄(征求意見(jian)稿(gao))》為(wei)自主(zhu)(zhu)品(pin)(pin)牌(pai)(pai)擴大在政(zheng)府采購的(de)(de)市場份額,為(wei)改(gai)變目前國內政(zheng)府采購以(yi)合資品(pin)(pin)牌(pai)(pai)產品(pin)(pin)為(wei)主(zhu)(zhu)的(de)(de)局面(mian)提(ti)供了保障。促進自主(zhu)(zhu)品(pin)(pin)牌(pai)(pai)發展,國產汽(qi)(qi)(qi)(qi)車(che)(che)業(ye)(ye)(ye)的(de)(de)繁榮將為(wei)汽(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)(jiao)的(de)(de)應(ying)用(yong)提(ti)供有力保障。預(yu)測(ce)未來3年,我國室溫硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)在汽(qi)(qi)(qi)(qi)車(che)(che)行業(ye)(ye)(ye)將以(yi)年均20%增(zeng)長。
此(ci)外(wai),硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)是重要(yao)的(de)(de)(de)(de)非石(shi)(shi)油(you)(you)(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)(you)(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)消費量的(de)(de)(de)(de)98%。但因(yin)為石(shi)(shi)油(you)(you)(you)價(jia)格的(de)(de)(de)(de)大幅(fu)上(shang)漲,同(tong)時我國在硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)關鍵(jian)原料有(you)機(ji)硅(gui)單體(ti)的(de)(de)(de)(de)生產技術方(fang)面取得(de)突(tu)破,有(you)機(ji)硅(gui)單體(ti)的(de)(de)(de)(de)生產技術在2005年前(qian)被幾(ji)家跨(kua)國公(gong)司壟(long)斷,但目前(qian)我國已(yi)發展成(cheng)為全球有(you)機(ji)硅(gui)單體(ti)第1大國,這(zhe)2個方(fang)面原因(yin)使(shi)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)價(jia)格從(cong)2011年起開(kai)始(shi)低于(yu)石(shi)(shi)油(you)(you)(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),僅(jin)約為大宗石(shi)(shi)油(you)(you)(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)80%~90%,成(cheng)為廉價(jia)的(de)(de)(de)(de)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),并開(kai)始(shi)大規模替代石(shi)(shi)油(you)(you)(you)基(ji)合成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。這(zhe)將(jiang)極大拓(tuo)展有(you)機(ji)硅(gui)產業的(de)(de)(de)(de)市場空(kong)間,同(tong)時將(jiang)帶動硅(gui)油(you)(you)(you)、硅(gui)烷偶聯劑(ji)和硅(gui)樹(shu)脂等其他有(you)機(ji)硅(gui)產品(pin)的(de)(de)(de)(de)消費。