硅橡膠是(shi)指主鏈(lian)由硅(gui)(gui)(gui)和(he)氧(yang)原子交替構成(cheng),硅(gui)(gui)(gui)原子上通(tong)常連(lian)有(you)兩(liang)個有(you)機(ji)基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)膠(jiao)。普通(tong)的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)(ji)和(he)少量(liang)乙烯基(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧(yang)鏈(lian)節組成(cheng)。苯(ben)基(ji)(ji)的(de)(de)(de)引入(ru)可(ke)(ke)提高硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐(nai)高、低(di)溫性(xing)(xing)(xing)能(neng),三氟丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引入(ru)則可(ke)(ke)提高硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐(nai)溫及耐(nai)油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)耐(nai)低(di)溫性(xing)(xing)(xing)能(neng)良(liang)好(hao),一般在(zai)-55℃下仍能(neng)工作(zuo)。引入(ru)苯(ben)基(ji)(ji)后,可(ke)(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)耐(nai)熱性(xing)(xing)(xing)能(neng)也(ye)很突出,在(zai)180℃下可(ke)(ke)長(chang)期工作(zuo),稍(shao)高于200℃也(ye)能(neng)承受數周或更(geng)長(chang)時間仍有(you)彈性(xing)(xing)(xing),瞬時可(ke)(ke)耐(nai)300℃以上的(de)(de)(de)高溫。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)透氣性(xing)(xing)(xing)好(hao),氧(yang)氣透過率(lv)在(zai)合成(cheng)聚合物中是(shi)較高的(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)還具(ju)有(you)生(sheng)理惰性(xing)(xing)(xing)、不(bu)會導致凝血的(de)(de)(de)突出特性(xing)(xing)(xing),因此在(zai)醫用領域(yu)應用廣泛。
主要品種
硅橡膠分類的方法很多,通常按固化
前的(de)形態分(fen)為固體硅(gui)(gui)橡膠(jiao)(jiao)和(he)液體硅(gui)(gui)橡膠(jiao)(jiao);按(an)硫化(hua)溫度分(fen)為室(shi)溫硫化(hua)硅(gui)(gui)橡膠(jiao)(jiao),高溫硫化(hua)硅(gui)(gui)橡膠(jiao)(jiao);按(an)所用(yong)單體的(de)不同,可分(fen)為甲基(ji)乙烯基(ji)硅(gui)(gui)橡膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡膠(jiao)(jiao)、氟硅(gui)(gui),腈(jing)硅(gui)(gui)橡膠(jiao)(jiao)等;按(an)性能(neng)和(he)用(yong)途的(de)不同又可分(fen)為通用(yong)型(xing)、超耐低溫型(xing)、超耐高溫型(xing)、高強力(li)型(xing)、耐油(you)型(xing)、醫用(yong)型(xing)等等。
發展(zhan)史
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)早期是由美國(guo)以三氯(lv)化(hua)(hua)鐵(tie)為催化(hua)(hua)劑(ji)合成的。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)產(chan)品問世。1948年(nian),采用(yong)高比(bi)表面積(ji)的氣相(xiang)法白(bai)炭(tan)黑補強(qiang)的硅(gui)(gui)橡(xiang)(xiang)膠(jiao)研制成功,使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的性能躍(yue)升(sheng)到實用(yong)階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產(chan)技(ji)術的基礎。從二(er)甲基二(er)氯(lv)硅(gui)(gui)烷合成開始生(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的國(guo)家(jia)有(you)美國(guo)。俄(e)羅斯、德國(guo)、日本、韓國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的工業(ye)(ye)化(hua)(hua)研究始于1957年(nian),多家(jia)研究所和企(qi)業(ye)(ye)陸(lu)續開發出(chu)各種硅(gui)(gui)橡(xiang)(xiang)膠(jiao)。到2003年(nian)底(di),中(zhong)國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產(chan)能力為135千(qian)噸,其(qi)中(zhong)高溫膠(jiao)100千(qian)噸。
高溫硫化硅(gui)橡膠
高溫硫(liu)(liu)化(hua)硅(gui)橡(xiang)(xiang)膠(jiao)是指聚硅(gui)氧(yang)烷變(bian)成(cheng)(cheng)彈性(xing)體的(de)(de)(de)過程(cheng)是經過高溫(110-170℃)硫(liu)(liu)化(hua)成(cheng)(cheng)型(xing)的(de)(de)(de)。它主要以(yi)高分子量的(de)(de)(de)聚甲基乙烯(xi)基硅(gui)氧(yang)烷為生膠(jiao),混入(ru)補強填料、硫(liu)(liu)化(hua)劑(ji)(ji)等,在加(jia)熱加(jia)壓(ya)下硫(liu)(liu)化(hua)成(cheng)(cheng)彈性(xing)體。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)補強主要是各種類型(xing)的(de)(de)(de)白炭黑,可使硫(liu)(liu)化(hua)膠(jiao)的(de)(de)(de)強度增(zeng)加(jia)數(shu)十倍(bei)。有(you)時(shi)為了降低成(cheng)(cheng)本或改善膠(jiao)料性(xing)能(neng)及賦予硫(liu)(liu)化(hua)膠(jiao)各種特殊的(de)(de)(de)性(xing)能(neng),也加(jia)入(ru)相應的(de)(de)(de)各種添加(jia)劑(ji)(ji)。硫(liu)(liu)化(hua)劑(ji)(ji)是各種有(you)機(ji)過氧(yang)化(hua)物(wu)或加(jia)成(cheng)(cheng)反應催化(hua)劑(ji)(ji)。
加工成型(xing)方法如圖所示。一次硫化(hua)的目(mu)的是(shi)進(jin)行高(gao)分子鏈(lian)的交(jiao)聯反應;二次硫化(hua)的目(mu)的是(shi)進(jin)行補充(chong)交(jiao)聯、驅(qu)除硫化(hua)劑(ji)分解產(chan)物和其(qi)他揮(hui)發性化(hua)合物以穩定(ding)硫化(hua)膠的各項性能。常(chang)用的設(she)備(bei)有開(kai)放式(shi)煉膠機、捏合機及真空(kong)密煉機。
主(zhu)要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特征是(shi)(shi)高(gao)溫(wen)(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)強度(du)(du)僅是(shi)(shi)天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)一半(ban),但(dan)在200℃以上的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)保持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度(du)(du),且(qie)力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)(wu)明顯變(bian)化。(2)低(di)(di)(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃化溫(wen)(wen)(wen)(wen)度(du)(du)一般為-70~-50℃,特殊配(pei)方(fang)可(ke)達-100℃,表(biao)明其低(di)(di)(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優異。這對航空、宇航工(gong)業的(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)紫(zi)外線等(deng)十分穩定,在不(bu)加任何(he)添加劑(ji)的(de)(de)情況(kuang)下(xia),就具有優良的(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有優異的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)電(dian)(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)(chang)好(hao)。(5)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比(bi)通用橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差(cha),但(dan)在150℃的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)低(di)(di)(di)溫(wen)(wen)(wen)(wen)下(xia),其物理(li)機械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優于通用橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及(ji)化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有中等(deng)的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)(ti)(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對空氣(qi)(qi)、氮、氧(yang)、二氧(yang)化碳(tan)等(deng)氣(qi)(qi)體(ti)(ti)(ti)的(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)然(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅,與人體(ti)(ti)(ti)組織(zhi)不(bu)粘(zhan)連,具有抗凝血作用,對肌體(ti)(ti)(ti)組織(zhi)的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)(chang)少。特別適合作為醫用材料。
硅橡(xiang)膠的用(yong)量
據(ju)中國(guo)汽(qi)車(che)(che)(che)(che)工(gong)業(ye)協會統計(ji),2012年(nian),汽(qi)車(che)(che)(che)(che)產銷(xiao)分別達到1927.18萬(wan)輛和(he)(he)(he)1930.64萬(wan)輛,同比分別增(zeng)長(chang)4.63%和(he)(he)(he)4.33%,汽(qi)車(che)(che)(che)(che)工(gong)業(ye)硅(gui)(gui)橡膠(jiao)(jiao)的用量約達2.0萬(wan)t。根據(ju)觀研天(tian)下(xia)的新(xin)研究,增(zeng)加有機(ji)硅(gui)(gui)材料(liao)在(zai)(zai)汽(qi)車(che)(che)(che)(che)零部件(jian)方面(mian)的用量,可以大幅(fu)度提(ti)高汽(qi)車(che)(che)(che)(che)的安(an)全(quan)性能,因此(ci),汽(qi)車(che)(che)(che)(che)產量和(he)(he)(he)單(dan)車(che)(che)(che)(che)用量水平的提(ti)高都將推動汽(qi)車(che)(che)(che)(che)工(gong)業(ye)對硅(gui)(gui)橡膠(jiao)(jiao)需求的增(zeng)加。國(guo)家鼓勵自(zi)主(zhu)(zhu)(zhu)品(pin)牌的汽(qi)車(che)(che)(che)(che)發展,關(guan)鍵汽(qi)車(che)(che)(che)(che)零部件(jian)實現自(zi)主(zhu)(zhu)(zhu)化,《2012年(nian)度黨政(zheng)機(ji)關(guan)公務用車(che)(che)(che)(che)選(xuan)用車(che)(che)(che)(che)型(xing)目(mu)錄(征求意見稿)》為(wei)自(zi)主(zhu)(zhu)(zhu)品(pin)牌擴大在(zai)(zai)政(zheng)府(fu)采(cai)購的市場份額,為(wei)改變目(mu)前(qian)國(guo)內政(zheng)府(fu)采(cai)購以合資品(pin)牌產品(pin)為(wei)主(zhu)(zhu)(zhu)的局面(mian)提(ti)供(gong)了(le)保(bao)障。促進自(zi)主(zhu)(zhu)(zhu)品(pin)牌發展,國(guo)產汽(qi)車(che)(che)(che)(che)業(ye)的繁榮將為(wei)汽(qi)車(che)(che)(che)(che)膠(jiao)(jiao)的應(ying)用提(ti)供(gong)有力保(bao)障。預測未來3年(nian),我國(guo)室溫硫化硅(gui)(gui)橡膠(jiao)(jiao)在(zai)(zai)汽(qi)車(che)(che)(che)(che)行(xing)業(ye)將以年(nian)均(jun)20%增(zeng)長(chang)。
此外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重(zhong)要(yao)的(de)非石油(you)(you)基合(he)成橡(xiang)(xiang)膠(jiao)(jiao),約占非石油(you)(you)基合(he)成橡(xiang)(xiang)膠(jiao)(jiao)消費(fei)量的(de)98%。但因(yin)為(wei)石油(you)(you)價格的(de)大(da)幅上漲,同時我國在(zai)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)關鍵原料有機硅(gui)單體(ti)的(de)生產技術(shu)方(fang)面取(qu)得突破,有機硅(gui)單體(ti)的(de)生產技術(shu)在(zai)2005年(nian)(nian)前被幾家跨(kua)國公(gong)司壟斷,但目前我國已發(fa)展(zhan)成為(wei)全球有機硅(gui)單體(ti)第1大(da)國,這(zhe)2個方(fang)面原因(yin)使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)價格從2011年(nian)(nian)起開始(shi)低于石油(you)(you)基合(he)成橡(xiang)(xiang)膠(jiao)(jiao),僅約為(wei)大(da)宗石油(you)(you)基橡(xiang)(xiang)膠(jiao)(jiao)的(de)80%~90%,成為(wei)廉價的(de)合(he)成橡(xiang)(xiang)膠(jiao)(jiao),并開始(shi)大(da)規模(mo)替代石油(you)(you)基合(he)成橡(xiang)(xiang)膠(jiao)(jiao)。這(zhe)將(jiang)(jiang)極(ji)大(da)拓展(zhan)有機硅(gui)產業的(de)市場(chang)空(kong)間,同時將(jiang)(jiang)帶動(dong)硅(gui)油(you)(you)、硅(gui)烷(wan)偶聯(lian)劑和硅(gui)樹(shu)脂等其他(ta)有機硅(gui)產品的(de)消費(fei)。