
硅橡膠是(shi)指(zhi)主鏈由硅(gui)(gui)和氧(yang)(yang)原(yuan)子(zi)交替(ti)構成(cheng),硅(gui)(gui)原(yuan)子(zi)上通常(chang)連有(you)兩個(ge)有(you)機基團的(de)橡(xiang)(xiang)(xiang)膠(jiao)。普通的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)主要(yao)由含甲(jia)基和少量(liang)乙烯基的(de)硅(gui)(gui)氧(yang)(yang)鏈節組成(cheng)。苯(ben)基的(de)引(yin)入(ru)可(ke)(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)高、低(di)溫(wen)性(xing)能,三氟丙基及氰(qing)基的(de)引(yin)入(ru)則(ze)可(ke)(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)溫(wen)及耐(nai)油性(xing)能。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)耐(nai)低(di)溫(wen)性(xing)能良好(hao),一(yi)般在-55℃下仍(reng)能工(gong)(gong)作。引(yin)入(ru)苯(ben)基后,可(ke)(ke)(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)熱性(xing)能也很突出,在180℃下可(ke)(ke)(ke)長期工(gong)(gong)作,稍(shao)高于200℃也能承(cheng)受數(shu)周(zhou)或更長時間仍(reng)有(you)彈性(xing),瞬時可(ke)(ke)(ke)耐(nai)300℃以上的(de)高溫(wen)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)透(tou)氣(qi)性(xing)好(hao),氧(yang)(yang)氣(qi)透(tou)過(guo)率在合成(cheng)聚合物(wu)中是(shi)較高的(de)。此(ci)(ci)外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)還具有(you)生理(li)惰性(xing)、不會導致凝(ning)血的(de)突出特性(xing),因(yin)此(ci)(ci)在醫(yi)用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠分(fen)(fen)類(lei)的(de)方法很多,通常按固化(hua)前(qian)的(de)形態分(fen)(fen)為(wei)固體硅(gui)(gui)橡(xiang)膠和液(ye)體硅(gui)(gui)橡(xiang)膠;按硫(liu)(liu)化(hua)溫(wen)度分(fen)(fen)為(wei)室溫(wen)硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)膠,高溫(wen)硫(liu)(liu)化(hua)硅(gui)(gui)橡(xiang)膠;按所用單體的(de)不(bu)同,可分(fen)(fen)為(wei)甲(jia)基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)膠,甲(jia)基(ji)苯基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)膠、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠等;按性(xing)能和用途的(de)不(bu)同又(you)可分(fen)(fen)為(wei)通用型(xing)、超耐(nai)(nai)低(di)溫(wen)型(xing)、超耐(nai)(nai)高溫(wen)型(xing)、高強(qiang)力型(xing)、耐(nai)(nai)油(you)型(xing)、醫用型(xing)等等。
發展史
硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)早(zao)期是由美國(guo)以三氯化(hua)鐵(tie)為(wei)催化(hua)劑合(he)成的(de)。1945年(nian)(nian),硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)產品問世(shi)。1948年(nian)(nian),采(cai)用高(gao)比(bi)表面積的(de)氣(qi)相(xiang)法白炭黑補強(qiang)的(de)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)制成功,使硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍(yue)升到實用階段,奠定了現代硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產技術的(de)基(ji)礎。從二甲基(ji)二氯硅(gui)烷合(he)成開始生產硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本(ben)、韓國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)工業化(hua)研(yan)究始于1957年(nian)(nian),多(duo)家研(yan)究所(suo)和(he)企業陸(lu)續開發出各種硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底,中(zhong)國(guo)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產能(neng)力為(wei)135千噸,其(qi)中(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫化(hua)(hua)硅(gui)橡(xiang)膠(jiao)是指聚硅(gui)氧(yang)烷變成彈性(xing)體的(de)(de)過(guo)程是經過(guo)高溫(110-170℃)硫化(hua)(hua)成型的(de)(de)。它(ta)主要以高分子量的(de)(de)聚甲基(ji)乙烯基(ji)硅(gui)氧(yang)烷為生膠(jiao),混入補強填料、硫化(hua)(hua)劑等,在加(jia)(jia)熱加(jia)(jia)壓下(xia)硫化(hua)(hua)成彈性(xing)體。硅(gui)橡(xiang)膠(jiao)的(de)(de)補強主要是各(ge)種(zhong)類(lei)型的(de)(de)白(bai)炭黑,可使硫化(hua)(hua)膠(jiao)的(de)(de)強度增(zeng)加(jia)(jia)數十(shi)倍。有(you)時為了降(jiang)低成本或(huo)(huo)改善膠(jiao)料性(xing)能及賦予硫化(hua)(hua)膠(jiao)各(ge)種(zhong)特(te)殊(shu)的(de)(de)性(xing)能,也加(jia)(jia)入相應(ying)的(de)(de)各(ge)種(zhong)添(tian)加(jia)(jia)劑。硫化(hua)(hua)劑是各(ge)種(zhong)有(you)機過(guo)氧(yang)化(hua)(hua)物(wu)或(huo)(huo)加(jia)(jia)成反應(ying)催化(hua)(hua)劑。
加工成型方法如圖(tu)所(suo)示。一(yi)次硫化的(de)目(mu)的(de)是進行高分子鏈的(de)交聯反應;二次硫化的(de)目(mu)的(de)是進行補充交聯、驅除硫化劑(ji)分解產(chan)物和其他揮發(fa)性(xing)化合物以(yi)穩定硫化膠的(de)各(ge)項性(xing)能。常用的(de)設備有開放式煉(lian)膠機、捏(nie)合機及真空密煉(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著(zhu)的(de)(de)(de)(de)(de)特(te)征是高(gao)溫(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度僅是天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但在(zai)(zai)200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下(xia),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持(chi)一(yi)定(ding)的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬(ying)度,且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低(di)(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度一(yi)般為-70~-50℃,特(te)殊(shu)配方可達-100℃,表明其(qi)低(di)(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)(de)(de)意(yi)義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵(jian)對(dui)氧、臭(chou)氧及紫(zi)外線等(deng)十分穩定(ding),在(zai)(zai)不加任何添加劑(ji)的(de)(de)(de)(de)(de)情況下(xia),就具(ju)有(you)優(you)良的(de)(de)(de)(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)優(you)異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好(hao)。(5)物理機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)(de)(de)(de)物理機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)(de)(de)低(di)(di)溫(wen)(wen)(wen)(wen)下(xia),其(qi)物理機(ji)(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)中(zhong)等(deng)的(de)(de)(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣、氮、氧、二氧化碳等(deng)氣體的(de)(de)(de)(de)(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人體組織不粘連,具(ju)有(you)抗凝血(xue)作用,對(dui)肌(ji)體組織的(de)(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少(shao)。特(te)別(bie)適合作為醫用材(cai)料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)工(gong)業協會統計,2012年(nian),汽(qi)(qi)車(che)產(chan)銷分別(bie)達到(dao)1927.18萬(wan)(wan)輛(liang)和1930.64萬(wan)(wan)輛(liang),同比分別(bie)增長(chang)4.63%和4.33%,汽(qi)(qi)車(che)工(gong)業硅橡膠的(de)(de)用(yong)量(liang)約達2.0萬(wan)(wan)t。根據觀研天下的(de)(de)新(xin)研究,增加(jia)(jia)有機(ji)硅材料在汽(qi)(qi)車(che)零部件(jian)方面(mian)的(de)(de)用(yong)量(liang),可以大(da)幅度(du)提(ti)高汽(qi)(qi)車(che)的(de)(de)安(an)全性能,因此(ci),汽(qi)(qi)車(che)產(chan)量(liang)和單車(che)用(yong)量(liang)水平的(de)(de)提(ti)高都將推動(dong)汽(qi)(qi)車(che)工(gong)業對硅橡膠需求(qiu)的(de)(de)增加(jia)(jia)。國(guo)家鼓(gu)勵自(zi)(zi)主品牌(pai)的(de)(de)汽(qi)(qi)車(che)發展,關鍵汽(qi)(qi)車(che)零部件(jian)實(shi)現自(zi)(zi)主化,《2012年(nian)度(du)黨(dang)政(zheng)(zheng)機(ji)關公(gong)務用(yong)車(che)選用(yong)車(che)型(xing)目(mu)(mu)錄(征求(qiu)意見稿(gao))》為(wei)自(zi)(zi)主品牌(pai)擴(kuo)大(da)在政(zheng)(zheng)府采購的(de)(de)市場(chang)份額,為(wei)改變(bian)目(mu)(mu)前國(guo)內政(zheng)(zheng)府采購以合(he)資品牌(pai)產(chan)品為(wei)主的(de)(de)局面(mian)提(ti)供(gong)(gong)了保障。促進(jin)自(zi)(zi)主品牌(pai)發展,國(guo)產(chan)汽(qi)(qi)車(che)業的(de)(de)繁榮將為(wei)汽(qi)(qi)車(che)膠的(de)(de)應用(yong)提(ti)供(gong)(gong)有力保障。預測未來(lai)3年(nian),我國(guo)室溫硫化硅橡膠在汽(qi)(qi)車(che)行業將以年(nian)均20%增長(chang)。
此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠是重(zhong)要的(de)非石(shi)(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠,約(yue)占非石(shi)(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠消費(fei)量的(de)98%。但(dan)因(yin)為石(shi)(shi)(shi)油(you)價(jia)格的(de)大(da)(da)幅上漲(zhang),同(tong)時(shi)我國在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)關鍵原(yuan)料有機硅(gui)(gui)(gui)單體(ti)的(de)生(sheng)產技術方面取得突(tu)破,有機硅(gui)(gui)(gui)單體(ti)的(de)生(sheng)產技術在(zai)2005年前(qian)(qian)被幾家跨(kua)國公司壟(long)斷,但(dan)目前(qian)(qian)我國已發展成(cheng)為全球有機硅(gui)(gui)(gui)單體(ti)第1大(da)(da)國,這2個方面原(yuan)因(yin)使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)價(jia)格從(cong)2011年起開(kai)始低于石(shi)(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠,僅約(yue)為大(da)(da)宗石(shi)(shi)(shi)油(you)基(ji)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)80%~90%,成(cheng)為廉價(jia)的(de)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠,并開(kai)始大(da)(da)規(gui)模(mo)替代石(shi)(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠。這將(jiang)極大(da)(da)拓展有機硅(gui)(gui)(gui)產業的(de)市場空(kong)間,同(tong)時(shi)將(jiang)帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)樹脂等其(qi)他(ta)有機硅(gui)(gui)(gui)產品的(de)消費(fei)。