硅橡膠是指主鏈由硅(gui)(gui)和氧原子交替構成(cheng),硅(gui)(gui)原子上通常連有(you)(you)兩個有(you)(you)機基(ji)(ji)團的(de)橡(xiang)膠(jiao)。普通的(de)硅(gui)(gui)橡(xiang)膠(jiao)主要由含甲基(ji)(ji)和少量乙烯基(ji)(ji)的(de)硅(gui)(gui)氧鏈節組成(cheng)。苯基(ji)(ji)的(de)引入可提(ti)高(gao)硅(gui)(gui)橡(xiang)膠(jiao)的(de)耐(nai)(nai)高(gao)、低(di)溫(wen)性(xing)能,三氟丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)引入則可提(ti)高(gao)硅(gui)(gui)橡(xiang)膠(jiao)的(de)耐(nai)(nai)溫(wen)及耐(nai)(nai)油性(xing)能。硅(gui)(gui)橡(xiang)膠(jiao)耐(nai)(nai)低(di)溫(wen)性(xing)能良好,一般(ban)在-55℃下仍能工作。引入苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)的(de)耐(nai)(nai)熱(re)性(xing)能也(ye)很(hen)突出(chu),在180℃下可長期(qi)工作,稍高(gao)于200℃也(ye)能承(cheng)受數周或(huo)更長時(shi)間(jian)仍有(you)(you)彈(dan)性(xing),瞬時(shi)可耐(nai)(nai)300℃以上的(de)高(gao)溫(wen)。硅(gui)(gui)橡(xiang)膠(jiao)的(de)透氣性(xing)好,氧氣透過(guo)率在合成(cheng)聚合物中(zhong)是較高(gao)的(de)。此(ci)外,硅(gui)(gui)橡(xiang)膠(jiao)還具有(you)(you)生理惰性(xing)、不會導致凝血的(de)突出(chu)特性(xing),因(yin)此(ci)在醫用(yong)領(ling)域(yu)應用(yong)廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)分(fen)類的(de)方(fang)法(fa)很(hen)多,通常按固化前(qian)的(de)形態(tai)分(fen)為固體硅(gui)(gui)橡(xiang)膠(jiao)和液(ye)體硅(gui)(gui)橡(xiang)膠(jiao);按硫化溫度分(fen)為室溫硫化硅(gui)(gui)橡(xiang)膠(jiao),高(gao)溫硫化硅(gui)(gui)橡(xiang)膠(jiao);按所用單(dan)體的(de)不同,可分(fen)為甲基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao),甲基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)等(deng);按性能(neng)和用途的(de)不同又可分(fen)為通用型(xing)、超耐(nai)低(di)溫型(xing)、超耐(nai)高(gao)溫型(xing)、高(gao)強力型(xing)、耐(nai)油型(xing)、醫(yi)用型(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)早期是由美(mei)國(guo)以(yi)三氯化鐵為(wei)催(cui)化劑(ji)合成的(de)(de)。1945年(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)產(chan)品(pin)問世。1948年(nian),采用高(gao)比表面積的(de)(de)氣相(xiang)法白炭黑補(bu)強(qiang)的(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)研(yan)制(zhi)成功(gong),使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)性能躍升到(dao)實用階段,奠定了(le)現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)技(ji)術的(de)(de)基礎(chu)。從二甲基二氯硅(gui)烷合成開(kai)始(shi)生(sheng)產(chan)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)國(guo)家(jia)有美(mei)國(guo)。俄羅斯、德國(guo)、日本、韓國(guo)和中(zhong)國(guo)等。中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)工業化研(yan)究始(shi)于1957年(nian),多家(jia)研(yan)究所和企(qi)業陸續開(kai)發出(chu)各種(zhong)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)國(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)生(sheng)產(chan)能力為(wei)135千噸(dun),其中(zhong)高(gao)溫膠(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)(jiao)是(shi)指聚硅(gui)(gui)氧(yang)烷變成(cheng)彈(dan)性體的過(guo)程是(shi)經過(guo)高(gao)溫(110-170℃)硫(liu)化(hua)成(cheng)型的。它主(zhu)要以高(gao)分子量的聚甲(jia)基(ji)乙烯(xi)基(ji)硅(gui)(gui)氧(yang)烷為(wei)(wei)生膠(jiao)(jiao),混(hun)入補(bu)強填料、硫(liu)化(hua)劑(ji)等(deng),在(zai)加熱加壓下硫(liu)化(hua)成(cheng)彈(dan)性體。硅(gui)(gui)橡膠(jiao)(jiao)的補(bu)強主(zhu)要是(shi)各種(zhong)(zhong)(zhong)類型的白(bai)炭黑,可(ke)使硫(liu)化(hua)膠(jiao)(jiao)的強度增加數十倍。有(you)時(shi)為(wei)(wei)了降(jiang)低成(cheng)本或(huo)(huo)改(gai)善膠(jiao)(jiao)料性能(neng)及賦予(yu)硫(liu)化(hua)膠(jiao)(jiao)各種(zhong)(zhong)(zhong)特殊的性能(neng),也加入相應的各種(zhong)(zhong)(zhong)添(tian)加劑(ji)。硫(liu)化(hua)劑(ji)是(shi)各種(zhong)(zhong)(zhong)有(you)機過(guo)氧(yang)化(hua)物(wu)或(huo)(huo)加成(cheng)反應催化(hua)劑(ji)。
加工成型方(fang)法如圖所示。一次硫(liu)(liu)化(hua)的目(mu)的是(shi)進行高分(fen)子鏈(lian)的交聯反(fan)應;二(er)次硫(liu)(liu)化(hua)的目(mu)的是(shi)進行補充交聯、驅除(chu)硫(liu)(liu)化(hua)劑(ji)分(fen)解(jie)產物(wu)和其他揮發性化(hua)合(he)(he)物(wu)以穩定硫(liu)(liu)化(hua)膠(jiao)(jiao)的各項性能。常用的設備有(you)開放(fang)式煉膠(jiao)(jiao)機、捏(nie)合(he)(he)機及真空密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)著(zhu)的(de)(de)(de)(de)(de)特(te)征是高溫(wen)(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)(du)僅(jin)是天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半(ban),但(dan)在(zai)200℃以上(shang)的(de)(de)(de)(de)(de)高溫(wen)(wen)(wen)(wen)(wen)環(huan)境下,硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)(de)柔(rou)韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du)(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯(xian)變化(hua)。(2)低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃(li)化(hua)溫(wen)(wen)(wen)(wen)(wen)度(du)(du)一(yi)般(ban)為-70~-50℃,特(te)殊配(pei)方可達-100℃,表明其低溫(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對(dui)(dui)航空、宇航工業的(de)(de)(de)(de)(de)意義(yi)重大(da)。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)(dui)氧(yang)、臭氧(yang)及紫(zi)外線等(deng)(deng)十分(fen)穩定(ding),在(zai)不加任何添加劑的(de)(de)(de)(de)(de)情況下,就具(ju)有(you)優良的(de)(de)(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)優異的(de)(de)(de)(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)下的(de)(de)(de)(de)(de)物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)(de)(de)(de)高溫(wen)(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)(de)低溫(wen)(wen)(wen)(wen)(wen)下,其物理(li)(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于(yu)通用橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)(deng)的(de)(de)(de)(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室(shi)溫(wen)(wen)(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)(dui)空氣(qi)(qi)、氮、氧(yang)、二氧(yang)化(hua)碳(tan)等(deng)(deng)氣(qi)(qi)體的(de)(de)(de)(de)(de)透(tou)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組織不粘(zhan)連,具(ju)有(you)抗凝血作用,對(dui)(dui)肌體組織的(de)(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作為醫用材料。
硅橡膠的用量
據(ju)中(zhong)國(guo)汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業(ye)協會統計,2012年(nian),汽(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)(chan)銷分別達(da)到1927.18萬輛(liang)和1930.64萬輛(liang),同(tong)比分別增長(chang)(chang)4.63%和4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業(ye)硅(gui)橡(xiang)(xiang)膠(jiao)的用(yong)量(liang)(liang)約達(da)2.0萬t。根據(ju)觀研(yan)天下的新研(yan)究,增加有(you)機(ji)硅(gui)材料在汽(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)件方面的用(yong)量(liang)(liang),可(ke)以(yi)大(da)(da)幅度提高汽(qi)(qi)(qi)(qi)車(che)(che)(che)的安全性能(neng),因此(ci),汽(qi)(qi)(qi)(qi)車(che)(che)(che)產(chan)(chan)量(liang)(liang)和單車(che)(che)(che)用(yong)量(liang)(liang)水平的提高都將(jiang)推(tui)動汽(qi)(qi)(qi)(qi)車(che)(che)(che)工業(ye)對硅(gui)橡(xiang)(xiang)膠(jiao)需求的增加。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)的汽(qi)(qi)(qi)(qi)車(che)(che)(che)發展(zhan)(zhan),關鍵(jian)汽(qi)(qi)(qi)(qi)車(che)(che)(che)零部(bu)件實現自(zi)主(zhu)化,《2012年(nian)度黨政(zheng)機(ji)關公務用(yong)車(che)(che)(che)選(xuan)用(yong)車(che)(che)(che)型目(mu)錄(征求意見稿)》為自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)擴大(da)(da)在政(zheng)府采(cai)購的市場份額,為改變(bian)目(mu)前國(guo)內(nei)政(zheng)府采(cai)購以(yi)合資品(pin)(pin)(pin)牌(pai)產(chan)(chan)品(pin)(pin)(pin)為主(zhu)的局面提供(gong)了保障。促進(jin)自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)發展(zhan)(zhan),國(guo)產(chan)(chan)汽(qi)(qi)(qi)(qi)車(che)(che)(che)業(ye)的繁榮(rong)將(jiang)為汽(qi)(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的應用(yong)提供(gong)有(you)力保障。預測未(wei)來3年(nian),我國(guo)室溫(wen)硫化硅(gui)橡(xiang)(xiang)膠(jiao)在汽(qi)(qi)(qi)(qi)車(che)(che)(che)行(xing)業(ye)將(jiang)以(yi)年(nian)均20%增長(chang)(chang)。
此外,硅(gui)(gui)(gui)橡膠(jiao)是重要的(de)(de)非石(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡膠(jiao),約占(zhan)非石(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡膠(jiao)消(xiao)費(fei)量的(de)(de)98%。但因為石(shi)油(you)價格(ge)的(de)(de)大(da)幅(fu)上漲(zhang),同(tong)時我國(guo)在硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)關(guan)鍵原料有(you)機硅(gui)(gui)(gui)單(dan)體(ti)的(de)(de)生產技術方面取得突破,有(you)機硅(gui)(gui)(gui)單(dan)體(ti)的(de)(de)生產技術在2005年(nian)前被幾家跨國(guo)公司壟斷,但目前我國(guo)已發展(zhan)成(cheng)(cheng)(cheng)為全球(qiu)有(you)機硅(gui)(gui)(gui)單(dan)體(ti)第1大(da)國(guo),這2個方面原因使硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)價格(ge)從2011年(nian)起開始低于石(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡膠(jiao),僅(jin)約為大(da)宗(zong)石(shi)油(you)基(ji)橡膠(jiao)的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為廉價的(de)(de)合(he)(he)成(cheng)(cheng)(cheng)橡膠(jiao),并開始大(da)規(gui)模替代石(shi)油(you)基(ji)合(he)(he)成(cheng)(cheng)(cheng)橡膠(jiao)。這將(jiang)極大(da)拓展(zhan)有(you)機硅(gui)(gui)(gui)產業的(de)(de)市場空間,同(tong)時將(jiang)帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷(wan)偶聯劑(ji)和硅(gui)(gui)(gui)樹脂等(deng)其他有(you)機硅(gui)(gui)(gui)產品的(de)(de)消(xiao)費(fei)。