硅橡膠是指(zhi)主(zhu)(zhu)鏈由硅(gui)和(he)氧(yang)(yang)原(yuan)子(zi)交替構成(cheng)(cheng),硅(gui)原(yuan)子(zi)上通(tong)常連有(you)兩個有(you)機(ji)基(ji)(ji)團的(de)(de)橡(xiang)膠(jiao)(jiao)。普通(tong)的(de)(de)硅(gui)橡(xiang)膠(jiao)(jiao)主(zhu)(zhu)要由含甲基(ji)(ji)和(he)少(shao)量乙(yi)烯基(ji)(ji)的(de)(de)硅(gui)氧(yang)(yang)鏈節組成(cheng)(cheng)。苯(ben)基(ji)(ji)的(de)(de)引入(ru)可提(ti)高(gao)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)高(gao)、低溫(wen)性(xing)(xing)(xing)能(neng)(neng),三氟丙基(ji)(ji)及(ji)(ji)氰基(ji)(ji)的(de)(de)引入(ru)則(ze)可提(ti)高(gao)硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)溫(wen)及(ji)(ji)耐(nai)(nai)油(you)性(xing)(xing)(xing)能(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)耐(nai)(nai)低溫(wen)性(xing)(xing)(xing)能(neng)(neng)良好,一般(ban)在-55℃下仍能(neng)(neng)工作。引入(ru)苯(ben)基(ji)(ji)后(hou),可達-73℃。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)熱(re)性(xing)(xing)(xing)能(neng)(neng)也很突(tu)出,在180℃下可長(chang)期工作,稍高(gao)于200℃也能(neng)(neng)承受數周(zhou)或更長(chang)時(shi)間仍有(you)彈性(xing)(xing)(xing),瞬時(shi)可耐(nai)(nai)300℃以上的(de)(de)高(gao)溫(wen)。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)好,氧(yang)(yang)氣(qi)透(tou)過率(lv)在合成(cheng)(cheng)聚(ju)合物中是較高(gao)的(de)(de)。此(ci)外(wai),硅(gui)橡(xiang)膠(jiao)(jiao)還具有(you)生理惰性(xing)(xing)(xing)、不會導致凝(ning)血的(de)(de)突(tu)出特性(xing)(xing)(xing),因此(ci)在醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)分類的(de)(de)方法很多,通常(chang)按(an)固化前(qian)的(de)(de)形態分為(wei)(wei)固體硅(gui)(gui)橡(xiang)膠(jiao)和液(ye)體硅(gui)(gui)橡(xiang)膠(jiao);按(an)硫化溫度(du)分為(wei)(wei)室溫硫化硅(gui)(gui)橡(xiang)膠(jiao),高(gao)溫硫化硅(gui)(gui)橡(xiang)膠(jiao);按(an)所用(yong)單體的(de)(de)不同,可(ke)分為(wei)(wei)甲基(ji)(ji)乙烯(xi)(xi)基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯(xi)(xi)基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)等;按(an)性能和用(yong)途的(de)(de)不同又可(ke)分為(wei)(wei)通用(yong)型(xing)(xing)(xing)(xing)、超耐(nai)低溫型(xing)(xing)(xing)(xing)、超耐(nai)高(gao)溫型(xing)(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)(xing)、耐(nai)油型(xing)(xing)(xing)(xing)、醫用(yong)型(xing)(xing)(xing)(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠早(zao)期是(shi)由美(mei)國(guo)(guo)以三氯化鐵(tie)為催(cui)化劑合成(cheng)的(de)(de)(de)。1945年,硅(gui)橡(xiang)(xiang)膠產(chan)品問世(shi)。1948年,采用(yong)高比表面積的(de)(de)(de)氣相(xiang)法白炭(tan)黑補強(qiang)的(de)(de)(de)硅(gui)橡(xiang)(xiang)膠研制成(cheng)功(gong),使硅(gui)橡(xiang)(xiang)膠的(de)(de)(de)性能(neng)(neng)躍升到實用(yong)階段,奠定了現代硅(gui)橡(xiang)(xiang)膠生(sheng)(sheng)產(chan)技(ji)術(shu)的(de)(de)(de)基礎。從二(er)甲(jia)基二(er)氯硅(gui)烷合成(cheng)開始(shi)生(sheng)(sheng)產(chan)硅(gui)橡(xiang)(xiang)膠的(de)(de)(de)國(guo)(guo)家有(you)美(mei)國(guo)(guo)。俄羅斯、德(de)國(guo)(guo)、日本、韓(han)國(guo)(guo)和中國(guo)(guo)等。中國(guo)(guo)硅(gui)橡(xiang)(xiang)膠的(de)(de)(de)工業化研究始(shi)于(yu)1957年,多家研究所和企業陸續(xu)開發出(chu)各種硅(gui)橡(xiang)(xiang)膠。到2003年底,中國(guo)(guo)硅(gui)橡(xiang)(xiang)膠生(sheng)(sheng)產(chan)能(neng)(neng)力為135千噸,其中高溫膠100千噸。
高溫硫化硅橡膠
高溫硫(liu)化(hua)(hua)(hua)硅橡膠是指聚硅氧(yang)烷(wan)變成彈(dan)性(xing)體的(de)過(guo)程是經過(guo)高溫(110-170℃)硫(liu)化(hua)(hua)(hua)成型的(de)。它(ta)主要以高分子量的(de)聚甲基乙烯基硅氧(yang)烷(wan)為(wei)生膠,混入補(bu)強(qiang)填(tian)料、硫(liu)化(hua)(hua)(hua)劑(ji)等,在加熱加壓下(xia)硫(liu)化(hua)(hua)(hua)成彈(dan)性(xing)體。硅橡膠的(de)補(bu)強(qiang)主要是各(ge)種(zhong)類(lei)型的(de)白炭黑,可使硫(liu)化(hua)(hua)(hua)膠的(de)強(qiang)度(du)增加數十倍。有時(shi)為(wei)了降(jiang)低(di)成本(ben)或改善(shan)膠料性(xing)能(neng)及賦予(yu)硫(liu)化(hua)(hua)(hua)膠各(ge)種(zhong)特(te)殊(shu)的(de)性(xing)能(neng),也加入相應的(de)各(ge)種(zhong)添加劑(ji)。硫(liu)化(hua)(hua)(hua)劑(ji)是各(ge)種(zhong)有機過(guo)氧(yang)化(hua)(hua)(hua)物或加成反(fan)應催化(hua)(hua)(hua)劑(ji)。
加(jia)工(gong)成型(xing)方法如圖所示(shi)。一次硫(liu)化(hua)的目的是進行高分(fen)子(zi)鏈(lian)的交(jiao)(jiao)聯反應;二(er)次硫(liu)化(hua)的目的是進行補充交(jiao)(jiao)聯、驅除硫(liu)化(hua)劑分(fen)解產物和(he)其他揮發性化(hua)合(he)物以(yi)穩定(ding)硫(liu)化(hua)膠(jiao)的各(ge)項(xiang)性能。常用的設備有開放式煉膠(jiao)機、捏合(he)機及真空(kong)密煉機。
主要性能
(1)高(gao)(gao)溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)顯著的(de)(de)(de)(de)特(te)(te)征(zheng)是(shi)(shi)高(gao)(gao)溫穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)溫下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)強度(du)僅是(shi)(shi)天(tian)然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)或某(mou)些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)一(yi)(yi)半,但(dan)在200℃以上的(de)(de)(de)(de)高(gao)(gao)溫環境下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)保持一(yi)(yi)定的(de)(de)(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬(ying)度(du),且(qie)力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)(wu)明顯變化(hua)。(2)低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)玻璃化(hua)溫度(du)一(yi)(yi)般為-70~-50℃,特(te)(te)殊配方可(ke)達(da)-100℃,表(biao)明其低溫性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)(de)意義(yi)重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)中(zhong)Si-O-Si鍵對(dui)氧、臭氧及紫外線等十分(fen)穩(wen)定,在不(bu)加(jia)任何添加(jia)劑(ji)的(de)(de)(de)(de)情況下(xia),就具(ju)有(you)優良的(de)(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)優異的(de)(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)(chang)好。(5)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)常(chang)(chang)溫下(xia)的(de)(de)(de)(de)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)在150℃的(de)(de)(de)(de)高(gao)(gao)溫和(he)-50℃的(de)(de)(de)(de)低溫下(xia),其物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于通用橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐油及化(hua)學(xue)試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)中(zhong)等的(de)(de)(de)(de)耐油、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體(ti)透(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)對(dui)空氣(qi)、氮、氧、二氧化(hua)碳(tan)等氣(qi)體(ti)的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)(gao)出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)(wu)毒(du),無(wu)(wu)味,無(wu)(wu)嗅(xiu),與人體(ti)組織不(bu)粘連,具(ju)有(you)抗凝(ning)血作用,對(dui)肌體(ti)組織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)(chang)少。特(te)(te)別(bie)適(shi)合作為醫用材料(liao)。
硅橡膠的用量
據中國(guo)汽(qi)車(che)(che)工(gong)業(ye)(ye)協會統計,2012年(nian),汽(qi)車(che)(che)產(chan)銷分(fen)別達到1927.18萬輛和(he)1930.64萬輛,同比分(fen)別增長4.63%和(he)4.33%,汽(qi)車(che)(che)工(gong)業(ye)(ye)硅(gui)橡膠(jiao)的用(yong)量約達2.0萬t。根(gen)據觀(guan)研天下(xia)的新研究,增加(jia)有機(ji)硅(gui)材料(liao)在汽(qi)車(che)(che)零部件(jian)方面的用(yong)量,可以大(da)幅度提(ti)高(gao)汽(qi)車(che)(che)的安(an)全性能(neng),因(yin)此,汽(qi)車(che)(che)產(chan)量和(he)單(dan)車(che)(che)用(yong)量水(shui)平的提(ti)高(gao)都將推(tui)動汽(qi)車(che)(che)工(gong)業(ye)(ye)對硅(gui)橡膠(jiao)需求(qiu)的增加(jia)。國(guo)家(jia)鼓勵(li)自(zi)主品(pin)(pin)(pin)牌(pai)(pai)的汽(qi)車(che)(che)發(fa)展,關鍵汽(qi)車(che)(che)零部件(jian)實現自(zi)主化,《2012年(nian)度黨政機(ji)關公務(wu)用(yong)車(che)(che)選用(yong)車(che)(che)型目(mu)錄(征(zheng)求(qiu)意見稿)》為自(zi)主品(pin)(pin)(pin)牌(pai)(pai)擴(kuo)大(da)在政府(fu)采(cai)購的市場份額,為改(gai)變目(mu)前(qian)國(guo)內政府(fu)采(cai)購以合(he)資品(pin)(pin)(pin)牌(pai)(pai)產(chan)品(pin)(pin)(pin)為主的局(ju)面提(ti)供(gong)(gong)了保障。促進自(zi)主品(pin)(pin)(pin)牌(pai)(pai)發(fa)展,國(guo)產(chan)汽(qi)車(che)(che)業(ye)(ye)的繁榮將為汽(qi)車(che)(che)膠(jiao)的應用(yong)提(ti)供(gong)(gong)有力保障。預(yu)測未(wei)來3年(nian),我國(guo)室(shi)溫硫化硅(gui)橡膠(jiao)在汽(qi)車(che)(che)行業(ye)(ye)將以年(nian)均20%增長。
此外,硅橡(xiang)膠(jiao)(jiao)是(shi)重要的(de)(de)(de)(de)(de)非石(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),約占非石(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)量的(de)(de)(de)(de)(de)98%。但因為石(shi)油(you)(you)價格的(de)(de)(de)(de)(de)大(da)(da)幅上漲(zhang),同時我(wo)國(guo)在硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)關鍵原料有(you)(you)(you)機(ji)(ji)(ji)硅單體的(de)(de)(de)(de)(de)生產技術方(fang)面(mian)取得突(tu)破,有(you)(you)(you)機(ji)(ji)(ji)硅單體的(de)(de)(de)(de)(de)生產技術在2005年(nian)前被幾家(jia)跨國(guo)公司(si)壟斷,但目前我(wo)國(guo)已發展成(cheng)為全球有(you)(you)(you)機(ji)(ji)(ji)硅單體第1大(da)(da)國(guo),這2個(ge)方(fang)面(mian)原因使(shi)硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)價格從2011年(nian)起開始低于石(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),僅約為大(da)(da)宗石(shi)油(you)(you)基(ji)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)80%~90%,成(cheng)為廉價的(de)(de)(de)(de)(de)合(he)成(cheng)橡(xiang)膠(jiao)(jiao),并開始大(da)(da)規模(mo)替代石(shi)油(you)(you)基(ji)合(he)成(cheng)橡(xiang)膠(jiao)(jiao)。這將(jiang)極(ji)大(da)(da)拓展有(you)(you)(you)機(ji)(ji)(ji)硅產業的(de)(de)(de)(de)(de)市場空(kong)間,同時將(jiang)帶動硅油(you)(you)、硅烷偶聯劑和(he)硅樹脂(zhi)等其他有(you)(you)(you)機(ji)(ji)(ji)硅產品的(de)(de)(de)(de)(de)消費(fei)。