
硅橡膠是指主鏈(lian)由硅(gui)(gui)(gui)和氧原子(zi)交替構成,硅(gui)(gui)(gui)原子(zi)上(shang)通常(chang)連有(you)兩個有(you)機基(ji)團(tuan)的(de)(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)。普通的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)主要由含(han)甲基(ji)和少量乙烯(xi)基(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧鏈(lian)節(jie)組成。苯基(ji)的(de)(de)(de)引入(ru)可(ke)提(ti)高硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)高、低(di)溫性(xing)(xing)(xing)(xing)(xing)能(neng)(neng),三氟丙(bing)基(ji)及(ji)氰基(ji)的(de)(de)(de)引入(ru)則可(ke)提(ti)高硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)溫及(ji)耐(nai)油性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)耐(nai)低(di)溫性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)良好,一般在-55℃下(xia)仍能(neng)(neng)工作。引入(ru)苯基(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)耐(nai)熱性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)也(ye)很突出,在180℃下(xia)可(ke)長(chang)期工作,稍(shao)高于(yu)200℃也(ye)能(neng)(neng)承受數周或更長(chang)時間仍有(you)彈性(xing)(xing)(xing)(xing)(xing),瞬(shun)時可(ke)耐(nai)300℃以上(shang)的(de)(de)(de)高溫。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)好,氧氣(qi)透(tou)過率在合成聚合物中是較(jiao)高的(de)(de)(de)。此(ci)外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)還(huan)具有(you)生理惰性(xing)(xing)(xing)(xing)(xing)、不會導(dao)致凝(ning)血(xue)的(de)(de)(de)突出特性(xing)(xing)(xing)(xing)(xing),因此(ci)在醫用(yong)領域應(ying)用(yong)廣泛。
主要品種
硅橡(xiang)(xiang)膠(jiao)(jiao)分(fen)類的方法很多(duo),通常按固化前的形態分(fen)為(wei)固體(ti)(ti)硅橡(xiang)(xiang)膠(jiao)(jiao)和液(ye)體(ti)(ti)硅橡(xiang)(xiang)膠(jiao)(jiao);按硫(liu)化溫(wen)度(du)分(fen)為(wei)室溫(wen)硫(liu)化硅橡(xiang)(xiang)膠(jiao)(jiao),高溫(wen)硫(liu)化硅橡(xiang)(xiang)膠(jiao)(jiao);按所用(yong)(yong)單體(ti)(ti)的不(bu)(bu)同,可(ke)分(fen)為(wei)甲基乙烯基硅橡(xiang)(xiang)膠(jiao)(jiao),甲基苯(ben)基乙烯基硅橡(xiang)(xiang)膠(jiao)(jiao)、氟硅,腈(jing)硅橡(xiang)(xiang)膠(jiao)(jiao)等;按性能和用(yong)(yong)途的不(bu)(bu)同又可(ke)分(fen)為(wei)通用(yong)(yong)型(xing)(xing)、超耐(nai)低溫(wen)型(xing)(xing)、超耐(nai)高溫(wen)型(xing)(xing)、高強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用(yong)(yong)型(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡膠(jiao)早期是由(you)美國以三氯(lv)化鐵為催化劑合成(cheng)(cheng)(cheng)的。1945年(nian),硅(gui)(gui)(gui)橡膠(jiao)產(chan)品問世(shi)。1948年(nian),采用(yong)高比表(biao)面積(ji)的氣相法白(bai)炭黑補強的硅(gui)(gui)(gui)橡膠(jiao)研制成(cheng)(cheng)(cheng)功,使硅(gui)(gui)(gui)橡膠(jiao)的性能躍升到(dao)實用(yong)階段,奠定(ding)了(le)現(xian)代硅(gui)(gui)(gui)橡膠(jiao)生產(chan)技(ji)術的基礎。從二(er)(er)甲基二(er)(er)氯(lv)硅(gui)(gui)(gui)烷合成(cheng)(cheng)(cheng)開始生產(chan)硅(gui)(gui)(gui)橡膠(jiao)的國家有美國。俄羅(luo)斯(si)、德國、日(ri)本、韓國和中國等。中國硅(gui)(gui)(gui)橡膠(jiao)的工業化研究始于1957年(nian),多家研究所(suo)和企業陸續(xu)開發出各(ge)種硅(gui)(gui)(gui)橡膠(jiao)。到(dao)2003年(nian)底,中國硅(gui)(gui)(gui)橡膠(jiao)生產(chan)能力為135千噸,其中高溫(wen)膠(jiao)100千噸。
高溫硫化硅橡膠
高(gao)(gao)溫(wen)硫化(hua)(hua)(hua)硅(gui)橡膠(jiao)(jiao)是指聚硅(gui)氧(yang)(yang)烷(wan)(wan)變成彈(dan)性體的(de)過(guo)程是經過(guo)高(gao)(gao)溫(wen)(110-170℃)硫化(hua)(hua)(hua)成型的(de)。它主要(yao)以高(gao)(gao)分(fen)子量的(de)聚甲基乙(yi)烯基硅(gui)氧(yang)(yang)烷(wan)(wan)為(wei)生膠(jiao)(jiao),混入(ru)補(bu)強填(tian)料、硫化(hua)(hua)(hua)劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓下硫化(hua)(hua)(hua)成彈(dan)性體。硅(gui)橡膠(jiao)(jiao)的(de)補(bu)強主要(yao)是各(ge)種(zhong)(zhong)類(lei)型的(de)白炭(tan)黑,可使硫化(hua)(hua)(hua)膠(jiao)(jiao)的(de)強度增加(jia)(jia)數十倍。有時為(wei)了降低成本或改(gai)善膠(jiao)(jiao)料性能及賦予硫化(hua)(hua)(hua)膠(jiao)(jiao)各(ge)種(zhong)(zhong)特(te)殊的(de)性能,也加(jia)(jia)入(ru)相(xiang)應的(de)各(ge)種(zhong)(zhong)添加(jia)(jia)劑(ji)。硫化(hua)(hua)(hua)劑(ji)是各(ge)種(zhong)(zhong)有機過(guo)氧(yang)(yang)化(hua)(hua)(hua)物或加(jia)(jia)成反(fan)應催化(hua)(hua)(hua)劑(ji)。
加工成型(xing)方法如(ru)圖所示。一次(ci)硫(liu)(liu)化(hua)的(de)(de)目(mu)的(de)(de)是進行(xing)高分子鏈的(de)(de)交聯(lian)(lian)反(fan)應;二次(ci)硫(liu)(liu)化(hua)的(de)(de)目(mu)的(de)(de)是進行(xing)補充交聯(lian)(lian)、驅(qu)除硫(liu)(liu)化(hua)劑分解產(chan)物(wu)和其他揮(hui)發性(xing)化(hua)合(he)物(wu)以穩定硫(liu)(liu)化(hua)膠的(de)(de)各項(xiang)性(xing)能。常用的(de)(de)設備有開放式煉膠機、捏合(he)機及(ji)真空(kong)密煉機。
主要性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)特征是(shi)高溫(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)強(qiang)度(du)(du)僅是(shi)天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或(huo)某(mou)些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)一半,但在200℃以上的(de)高溫(wen)環境下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一定的(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)(biao)面硬度(du)(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明(ming)顯變化(hua)。(2)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)玻璃化(hua)溫(wen)度(du)(du)一般為-70~-50℃,特殊配方可達-100℃,表(biao)(biao)明(ming)其低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)異。這對(dui)航空、宇航工業的(de)意義重(zhong)大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及紫外線(xian)等(deng)(deng)十分穩定,在不加任何添加劑(ji)的(de)情況下(xia),就具有(you)(you)優(you)(you)良的(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)(you)優(you)(you)異的(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)下(xia)的(de)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差(cha),但在150℃的(de)高溫(wen)和(he)-50℃的(de)低(di)溫(wen)下(xia),其物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)于通(tong)用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)(you)中等(deng)(deng)的(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室(shi)溫(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)、二氧(yang)化(hua)碳等(deng)(deng)氣(qi)體(ti)的(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與人體(ti)組織(zhi)不粘(zhan)連(lian),具有(you)(you)抗凝血作(zuo)用(yong),對(dui)肌體(ti)組織(zhi)的(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少(shao)。特別適(shi)合作(zuo)為醫用(yong)材料。
硅橡膠的用量
據(ju)中(zhong)國(guo)汽(qi)車(che)(che)工業(ye)協會統計,2012年(nian),汽(qi)車(che)(che)產(chan)(chan)銷分(fen)別(bie)(bie)達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比分(fen)別(bie)(bie)增(zeng)(zeng)長(chang)4.63%和4.33%,汽(qi)車(che)(che)工業(ye)硅(gui)橡(xiang)膠的(de)(de)(de)用量約(yue)達2.0萬(wan)t。根據(ju)觀研天下的(de)(de)(de)新研究,增(zeng)(zeng)加有機(ji)硅(gui)材料在(zai)汽(qi)車(che)(che)零(ling)部件方面(mian)的(de)(de)(de)用量,可(ke)以大(da)幅(fu)度提高(gao)(gao)汽(qi)車(che)(che)的(de)(de)(de)安全性能,因此,汽(qi)車(che)(che)產(chan)(chan)量和單車(che)(che)用量水(shui)平的(de)(de)(de)提高(gao)(gao)都(dou)將推(tui)動(dong)汽(qi)車(che)(che)工業(ye)對(dui)硅(gui)橡(xiang)膠需求的(de)(de)(de)增(zeng)(zeng)加。國(guo)家鼓勵自(zi)主(zhu)(zhu)品牌(pai)的(de)(de)(de)汽(qi)車(che)(che)發展,關鍵汽(qi)車(che)(che)零(ling)部件實(shi)現自(zi)主(zhu)(zhu)化(hua),《2012年(nian)度黨政(zheng)(zheng)(zheng)機(ji)關公務用車(che)(che)選用車(che)(che)型目(mu)(mu)錄(征求意見稿(gao))》為自(zi)主(zhu)(zhu)品牌(pai)擴大(da)在(zai)政(zheng)(zheng)(zheng)府采購(gou)的(de)(de)(de)市(shi)場份額,為改變目(mu)(mu)前國(guo)內政(zheng)(zheng)(zheng)府采購(gou)以合資品牌(pai)產(chan)(chan)品為主(zhu)(zhu)的(de)(de)(de)局面(mian)提供(gong)了(le)保(bao)障。促進自(zi)主(zhu)(zhu)品牌(pai)發展,國(guo)產(chan)(chan)汽(qi)車(che)(che)業(ye)的(de)(de)(de)繁(fan)榮將為汽(qi)車(che)(che)膠的(de)(de)(de)應用提供(gong)有力保(bao)障。預測未來3年(nian),我國(guo)室溫(wen)硫化(hua)硅(gui)橡(xiang)膠在(zai)汽(qi)車(che)(che)行(xing)業(ye)將以年(nian)均20%增(zeng)(zeng)長(chang)。
此(ci)外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)是(shi)重要的(de)(de)非(fei)石(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),約(yue)占非(fei)石(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)消(xiao)費(fei)量的(de)(de)98%。但因為(wei)石(shi)(shi)油(you)價格的(de)(de)大幅上漲(zhang),同(tong)時我國(guo)在硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)關鍵原(yuan)料有機(ji)硅(gui)(gui)單(dan)體的(de)(de)生產技術方面取得突破,有機(ji)硅(gui)(gui)單(dan)體的(de)(de)生產技術在2005年(nian)前被幾家跨國(guo)公(gong)司壟(long)斷,但目前我國(guo)已發展(zhan)成(cheng)(cheng)(cheng)為(wei)全球有機(ji)硅(gui)(gui)單(dan)體第1大國(guo),這(zhe)2個(ge)方面原(yuan)因使(shi)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)價格從2011年(nian)起開(kai)始低于(yu)石(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),僅(jin)約(yue)為(wei)大宗石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉價的(de)(de)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),并開(kai)始大規模替(ti)代石(shi)(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。這(zhe)將極大拓展(zhan)有機(ji)硅(gui)(gui)產業的(de)(de)市場空間,同(tong)時將帶動硅(gui)(gui)油(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹(shu)脂(zhi)等其他(ta)有機(ji)硅(gui)(gui)產品的(de)(de)消(xiao)費(fei)。