
硅橡膠是指主(zhu)鏈由硅(gui)(gui)和(he)氧原子(zi)交替(ti)構成,硅(gui)(gui)原子(zi)上通(tong)常連有(you)兩個有(you)機基(ji)(ji)團的(de)(de)(de)(de)橡(xiang)膠(jiao)。普通(tong)的(de)(de)(de)(de)硅(gui)(gui)橡(xiang)膠(jiao)主(zhu)要由含甲基(ji)(ji)和(he)少量乙(yi)烯基(ji)(ji)的(de)(de)(de)(de)硅(gui)(gui)氧鏈節組(zu)成。苯基(ji)(ji)的(de)(de)(de)(de)引(yin)入(ru)可(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐(nai)(nai)高、低溫(wen)性(xing)(xing)能(neng)(neng),三氟丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)(de)引(yin)入(ru)則可(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油(you)性(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)耐(nai)(nai)低溫(wen)性(xing)(xing)能(neng)(neng)良好(hao),一般(ban)在-55℃下仍能(neng)(neng)工(gong)作。引(yin)入(ru)苯基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐(nai)(nai)熱性(xing)(xing)能(neng)(neng)也(ye)很突(tu)出,在180℃下可(ke)長(chang)期工(gong)作,稍高于200℃也(ye)能(neng)(neng)承(cheng)受數周(zhou)或更長(chang)時(shi)間(jian)仍有(you)彈性(xing)(xing),瞬(shun)時(shi)可(ke)耐(nai)(nai)300℃以(yi)上的(de)(de)(de)(de)高溫(wen)。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)透氣性(xing)(xing)好(hao),氧氣透過率在合成聚(ju)合物中(zhong)是較高的(de)(de)(de)(de)。此外,硅(gui)(gui)橡(xiang)膠(jiao)還(huan)具有(you)生(sheng)理惰性(xing)(xing)、不會(hui)導致凝(ning)血(xue)的(de)(de)(de)(de)突(tu)出特性(xing)(xing),因(yin)此在醫用領域應(ying)用廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)分(fen)類(lei)的(de)(de)方法(fa)很多,通(tong)常按固化(hua)(hua)前的(de)(de)形態(tai)分(fen)為(wei)固體(ti)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)和液體(ti)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao);按硫(liu)(liu)化(hua)(hua)溫(wen)(wen)度分(fen)為(wei)室溫(wen)(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao),高(gao)溫(wen)(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao);按所用單體(ti)的(de)(de)不(bu)同(tong),可(ke)分(fen)為(wei)甲基乙烯基硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao),甲基苯基乙烯基硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)等;按性能和用途的(de)(de)不(bu)同(tong)又可(ke)分(fen)為(wei)通(tong)用型、超(chao)耐(nai)低溫(wen)(wen)型、超(chao)耐(nai)高(gao)溫(wen)(wen)型、高(gao)強力型、耐(nai)油型、醫用型等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)早期是由美(mei)(mei)國(guo)以三(san)氯(lv)化鐵為催化劑(ji)合成的。1945年,硅(gui)(gui)橡(xiang)膠(jiao)產(chan)品問世。1948年,采用(yong)(yong)高比(bi)表面積的氣相(xiang)法白炭黑補強的硅(gui)(gui)橡(xiang)膠(jiao)研(yan)制成功(gong),使硅(gui)(gui)橡(xiang)膠(jiao)的性能躍升到實用(yong)(yong)階段,奠定了(le)現代硅(gui)(gui)橡(xiang)膠(jiao)生產(chan)技術的基(ji)礎。從(cong)二(er)甲基(ji)二(er)氯(lv)硅(gui)(gui)烷合成開始(shi)生產(chan)硅(gui)(gui)橡(xiang)膠(jiao)的國(guo)家(jia)有美(mei)(mei)國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)橡(xiang)膠(jiao)的工業(ye)(ye)化研(yan)究始(shi)于1957年,多家(jia)研(yan)究所和企(qi)業(ye)(ye)陸續開發出(chu)各(ge)種硅(gui)(gui)橡(xiang)膠(jiao)。到2003年底,中國(guo)硅(gui)(gui)橡(xiang)膠(jiao)生產(chan)能力為135千(qian)噸,其中高溫(wen)膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫硫化(hua)(hua)硅橡膠(jiao)是指聚(ju)硅氧烷變(bian)成(cheng)彈性(xing)體的(de)過程是經過高溫(110-170℃)硫化(hua)(hua)成(cheng)型(xing)的(de)。它主要以高分子(zi)量(liang)的(de)聚(ju)甲基(ji)乙烯基(ji)硅氧烷為(wei)生膠(jiao),混入補強填料、硫化(hua)(hua)劑(ji)(ji)等,在(zai)加(jia)熱加(jia)壓下硫化(hua)(hua)成(cheng)彈性(xing)體。硅橡膠(jiao)的(de)補強主要是各(ge)種(zhong)類型(xing)的(de)白(bai)炭黑,可(ke)使硫化(hua)(hua)膠(jiao)的(de)強度增(zeng)加(jia)數十倍。有時為(wei)了降低(di)成(cheng)本或(huo)(huo)改善(shan)膠(jiao)料性(xing)能及賦予(yu)硫化(hua)(hua)膠(jiao)各(ge)種(zhong)特殊的(de)性(xing)能,也(ye)加(jia)入相應的(de)各(ge)種(zhong)添加(jia)劑(ji)(ji)。硫化(hua)(hua)劑(ji)(ji)是各(ge)種(zhong)有機(ji)過氧化(hua)(hua)物或(huo)(huo)加(jia)成(cheng)反(fan)應催化(hua)(hua)劑(ji)(ji)。
加工成型方法(fa)如圖所示(shi)。一次(ci)硫化(hua)的目的是進行高分子鏈(lian)的交聯(lian)反(fan)應;二(er)次(ci)硫化(hua)的目的是進行補充交聯(lian)、驅除硫化(hua)劑分解產物和其他揮發性化(hua)合物以穩(wen)定硫化(hua)膠(jiao)(jiao)的各項性能。常(chang)用的設備有開放式煉(lian)膠(jiao)(jiao)機、捏合機及(ji)真空密(mi)煉(lian)機。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的特征是高(gao)溫(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的強度(du)僅是天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)或某些(xie)合(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的一半,但在(zai)200℃以上的高(gao)溫(wen)環(huan)境(jing)下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)保持一定的柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面(mian)硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)(wu)明(ming)顯(xian)變(bian)化(hua)。(2)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的玻璃(li)化(hua)溫(wen)度(du)一般為(wei)-70~-50℃,特殊配方可(ke)達-100℃,表明(ming)其(qi)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對航空、宇(yu)航工(gong)業的意義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵(jian)對氧、臭氧及紫外線等十分穩(wen)定,在(zai)不(bu)加任何(he)添加劑的情況下(xia),就具(ju)有(you)優良的耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)優異的絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)常溫(wen)下(xia)的物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在(zai)150℃的高(gao)溫(wen)和(he)-50℃的低(di)溫(wen)下(xia),其(qi)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)中等的耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)(ti)(ti)透(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)對空氣(qi)、氮、氧、二氧化(hua)碳(tan)等氣(qi)體(ti)(ti)(ti)的透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生(sheng)理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅(xiu),與人體(ti)(ti)(ti)組織不(bu)粘連,具(ju)有(you)抗凝血作用(yong),對肌體(ti)(ti)(ti)組織的反應性(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別(bie)適合(he)作為(wei)醫(yi)用(yong)材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)(qi)車(che)(che)產(chan)銷(xiao)分別達(da)到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同(tong)比分別增長(chang)(chang)4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)硅(gui)(gui)橡膠(jiao)的(de)(de)(de)(de)用(yong)(yong)(yong)量(liang)約達(da)2.0萬(wan)t。根據觀(guan)研天下的(de)(de)(de)(de)新研究(jiu),增加(jia)有機硅(gui)(gui)材(cai)料在(zai)汽(qi)(qi)(qi)車(che)(che)零部(bu)件(jian)方面(mian)的(de)(de)(de)(de)用(yong)(yong)(yong)量(liang),可以(yi)大幅(fu)度提高汽(qi)(qi)(qi)車(che)(che)的(de)(de)(de)(de)安(an)全性能,因此,汽(qi)(qi)(qi)車(che)(che)產(chan)量(liang)和單車(che)(che)用(yong)(yong)(yong)量(liang)水平的(de)(de)(de)(de)提高都(dou)將推動汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業(ye)對硅(gui)(gui)橡膠(jiao)需求(qiu)的(de)(de)(de)(de)增加(jia)。國家鼓勵自(zi)主(zhu)(zhu)(zhu)品(pin)(pin)牌(pai)的(de)(de)(de)(de)汽(qi)(qi)(qi)車(che)(che)發展,關鍵汽(qi)(qi)(qi)車(che)(che)零部(bu)件(jian)實現自(zi)主(zhu)(zhu)(zhu)化,《2012年(nian)(nian)度黨(dang)政(zheng)機關公(gong)務用(yong)(yong)(yong)車(che)(che)選用(yong)(yong)(yong)車(che)(che)型(xing)目錄(征求(qiu)意見稿(gao))》為(wei)(wei)自(zi)主(zhu)(zhu)(zhu)品(pin)(pin)牌(pai)擴(kuo)大在(zai)政(zheng)府采購(gou)的(de)(de)(de)(de)市場(chang)份額,為(wei)(wei)改變(bian)目前(qian)國內政(zheng)府采購(gou)以(yi)合資(zi)品(pin)(pin)牌(pai)產(chan)品(pin)(pin)為(wei)(wei)主(zhu)(zhu)(zhu)的(de)(de)(de)(de)局面(mian)提供了(le)保(bao)障。促進自(zi)主(zhu)(zhu)(zhu)品(pin)(pin)牌(pai)發展,國產(chan)汽(qi)(qi)(qi)車(che)(che)業(ye)的(de)(de)(de)(de)繁(fan)榮將為(wei)(wei)汽(qi)(qi)(qi)車(che)(che)膠(jiao)的(de)(de)(de)(de)應用(yong)(yong)(yong)提供有力(li)保(bao)障。預測未來3年(nian)(nian),我國室溫(wen)硫化硅(gui)(gui)橡膠(jiao)在(zai)汽(qi)(qi)(qi)車(che)(che)行業(ye)將以(yi)年(nian)(nian)均20%增長(chang)(chang)。
此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重要(yao)的非(fei)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消(xiao)費量(liang)的98%。但因為石(shi)(shi)油(you)(you)(you)價(jia)(jia)格的大幅上(shang)漲,同(tong)時(shi)(shi)我國在(zai)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的關鍵原料(liao)有機(ji)硅(gui)(gui)單(dan)體的生產(chan)(chan)技(ji)術(shu)方面(mian)取得突破,有機(ji)硅(gui)(gui)單(dan)體的生產(chan)(chan)技(ji)術(shu)在(zai)2005年前被幾家(jia)跨國公司壟斷,但目(mu)前我國已發(fa)展成(cheng)為全球(qiu)有機(ji)硅(gui)(gui)單(dan)體第1大國,這2個方面(mian)原因使(shi)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的價(jia)(jia)格從(cong)2011年起(qi)開始低(di)于(yu)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約為大宗石(shi)(shi)油(you)(you)(you)基(ji)(ji)橡(xiang)(xiang)膠(jiao)(jiao)的80%~90%,成(cheng)為廉價(jia)(jia)的合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開始大規模替代石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將(jiang)極大拓展有機(ji)硅(gui)(gui)產(chan)(chan)業的市場空間(jian),同(tong)時(shi)(shi)將(jiang)帶動硅(gui)(gui)油(you)(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂等其(qi)他(ta)有機(ji)硅(gui)(gui)產(chan)(chan)品的消(xiao)費。