硅橡膠是(shi)(shi)指主鏈(lian)由硅(gui)和氧(yang)原(yuan)子(zi)交替構成,硅(gui)原(yuan)子(zi)上(shang)通常連(lian)有兩(liang)個有機基團(tuan)的(de)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)主要(yao)由含甲基和少量乙(yi)烯基的(de)硅(gui)氧(yang)鏈(lian)節組成。苯基的(de)引(yin)入可(ke)提(ti)高硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐高、低溫性能,三氟(fu)丙基及氰(qing)基的(de)引(yin)入則(ze)可(ke)提(ti)高硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐溫及耐油性能。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)耐低溫性能良好,一般在(zai)-55℃下仍(reng)(reng)能工作。引(yin)入苯基后(hou),可(ke)達(da)-73℃。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐熱性能也很(hen)突(tu)出(chu),在(zai)180℃下可(ke)長期(qi)工作,稍高于200℃也能承受數(shu)周或更長時間仍(reng)(reng)有彈性,瞬(shun)時可(ke)耐300℃以上(shang)的(de)高溫。硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)透(tou)氣性好,氧(yang)氣透(tou)過(guo)率在(zai)合(he)成聚合(he)物(wu)中是(shi)(shi)較(jiao)高的(de)。此外(wai),硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有生理惰性、不會導致(zhi)凝血的(de)突(tu)出(chu)特性,因此在(zai)醫用(yong)領域(yu)應(ying)用(yong)廣(guang)泛(fan)。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)分類的(de)方(fang)法(fa)很(hen)多,通常按(an)(an)(an)固化(hua)前的(de)形態分為固體硅(gui)橡(xiang)(xiang)膠(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao);按(an)(an)(an)硫化(hua)溫(wen)(wen)度分為室溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao),高溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠(jiao);按(an)(an)(an)所用(yong)(yong)(yong)單體的(de)不(bu)同,可(ke)分為甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)(ji)苯基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)等(deng)(deng);按(an)(an)(an)性能和用(yong)(yong)(yong)途(tu)的(de)不(bu)同又(you)可(ke)分為通用(yong)(yong)(yong)型、超(chao)耐(nai)低溫(wen)(wen)型、超(chao)耐(nai)高溫(wen)(wen)型、高強力型、耐(nai)油(you)型、醫用(yong)(yong)(yong)型等(deng)(deng)等(deng)(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)早期是由美國以三氯化鐵為催(cui)化劑合(he)成的(de)。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)產品問世。1948年,采用高比表面(mian)積的(de)氣相法白炭黑補(bu)強的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)研(yan)制成功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)性能(neng)(neng)躍(yue)升到實用階段,奠定了現(xian)代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生(sheng)產技(ji)術的(de)基礎。從二甲(jia)基二氯硅(gui)(gui)烷(wan)合(he)成開始生(sheng)產硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)國家有美國。俄(e)羅(luo)斯(si)、德國、日本、韓(han)國和(he)中(zhong)國等。中(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)工(gong)業化研(yan)究始于1957年,多家研(yan)究所和(he)企業陸(lu)續開發出各種硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。到2003年底,中(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生(sheng)產能(neng)(neng)力為135千噸(dun),其中(zhong)高溫膠(jiao)(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫(liu)(liu)化(hua)(hua)硅(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)氧烷變成彈性(xing)體的過(guo)程(cheng)是(shi)(shi)經(jing)過(guo)高溫(110-170℃)硫(liu)(liu)化(hua)(hua)成型(xing)的。它(ta)主(zhu)(zhu)要以(yi)高分子量的聚甲基(ji)乙烯基(ji)硅(gui)氧烷為(wei)生膠(jiao)(jiao),混入(ru)補強填料(liao)、硫(liu)(liu)化(hua)(hua)劑等,在加(jia)熱加(jia)壓下硫(liu)(liu)化(hua)(hua)成彈性(xing)體。硅(gui)橡膠(jiao)(jiao)的補強主(zhu)(zhu)要是(shi)(shi)各種(zhong)(zhong)類型(xing)的白炭黑,可(ke)使硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)的強度增加(jia)數十倍。有(you)時(shi)為(wei)了(le)降(jiang)低成本(ben)或(huo)改善(shan)膠(jiao)(jiao)料(liao)性(xing)能及賦予(yu)硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)各種(zhong)(zhong)特殊的性(xing)能,也加(jia)入(ru)相應(ying)的各種(zhong)(zhong)添加(jia)劑。硫(liu)(liu)化(hua)(hua)劑是(shi)(shi)各種(zhong)(zhong)有(you)機過(guo)氧化(hua)(hua)物或(huo)加(jia)成反應(ying)催化(hua)(hua)劑。
加(jia)工成型方(fang)法如(ru)圖(tu)所示。一次硫(liu)(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是進行高分子(zi)鏈的(de)(de)交聯反應;二次硫(liu)(liu)化(hua)(hua)的(de)(de)目(mu)的(de)(de)是進行補充交聯、驅除硫(liu)(liu)化(hua)(hua)劑分解產物和(he)其他揮發(fa)性(xing)化(hua)(hua)合(he)物以(yi)穩定硫(liu)(liu)化(hua)(hua)膠的(de)(de)各項性(xing)能(neng)。常用的(de)(de)設備有開放式煉膠機、捏合(he)機及真空密煉機。
主要性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)(de)(de)特(te)征是高溫(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常(chang)溫(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)(de)強度僅是天然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)(de)一半,但在200℃以(yi)上的(de)(de)(de)(de)(de)(de)高溫(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一定的(de)(de)(de)(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬(ying)度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無明顯(xian)變(bian)化(hua)(hua)。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)(de)(de)玻璃化(hua)(hua)溫(wen)度一般為(wei)-70~-50℃,特(te)殊配方可達(da)-100℃,表(biao)明其低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)異(yi)。這對(dui)航空、宇(yu)航工(gong)業(ye)的(de)(de)(de)(de)(de)(de)意義重大(da)。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫外線等十分穩定,在不加任何添加劑(ji)的(de)(de)(de)(de)(de)(de)情況(kuang)下,就具(ju)(ju)有(you)優(you)良的(de)(de)(de)(de)(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)優(you)異(yi)的(de)(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常(chang)好。(5)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)下的(de)(de)(de)(de)(de)(de)物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比(bi)通(tong)用橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)(de)(de)高溫(wen)和-50℃的(de)(de)(de)(de)(de)(de)低溫(wen)下,其物(wu)(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)于通(tong)用橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油(you)(you)及化(hua)(hua)學(xue)試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)有(you)中(zhong)等的(de)(de)(de)(de)(de)(de)耐(nai)(nai)油(you)(you)、耐(nai)(nai)溶(rong)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)空氣、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)(hua)碳等氣體(ti)的(de)(de)(de)(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無毒,無味,無嗅,與人體(ti)組織不粘連,具(ju)(ju)有(you)抗凝血作用,對(dui)肌體(ti)組織的(de)(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特(te)別適合作為(wei)醫用材料。
硅橡膠的用量
據(ju)中國(guo)(guo)汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)協會統計(ji),2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車(che)(che)產銷分別達(da)到1927.18萬輛和(he)1930.64萬輛,同比分別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的用(yong)量(liang)(liang)約達(da)2.0萬t。根據(ju)觀(guan)研(yan)天下的新研(yan)究(jiu),增(zeng)加有(you)機(ji)硅(gui)(gui)材料在汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件(jian)方面的用(yong)量(liang)(liang),可(ke)以大幅度提高(gao)汽(qi)(qi)(qi)(qi)車(che)(che)的安全性能(neng),因(yin)此,汽(qi)(qi)(qi)(qi)車(che)(che)產量(liang)(liang)和(he)單(dan)車(che)(che)用(yong)量(liang)(liang)水平的提高(gao)都將推動汽(qi)(qi)(qi)(qi)車(che)(che)工業(ye)對(dui)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)需(xu)求的增(zeng)加。國(guo)(guo)家鼓勵自(zi)(zi)主(zhu)品(pin)(pin)(pin)牌(pai)(pai)的汽(qi)(qi)(qi)(qi)車(che)(che)發展(zhan)(zhan),關鍵汽(qi)(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件(jian)實現自(zi)(zi)主(zhu)化,《2012年(nian)(nian)度黨政(zheng)機(ji)關公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(征(zheng)求意見稿)》為(wei)自(zi)(zi)主(zhu)品(pin)(pin)(pin)牌(pai)(pai)擴大在政(zheng)府采購(gou)的市場份額,為(wei)改變目前國(guo)(guo)內政(zheng)府采購(gou)以合資品(pin)(pin)(pin)牌(pai)(pai)產品(pin)(pin)(pin)為(wei)主(zhu)的局面提供(gong)了保障。促進自(zi)(zi)主(zhu)品(pin)(pin)(pin)牌(pai)(pai)發展(zhan)(zhan),國(guo)(guo)產汽(qi)(qi)(qi)(qi)車(che)(che)業(ye)的繁(fan)榮將為(wei)汽(qi)(qi)(qi)(qi)車(che)(che)膠(jiao)(jiao)的應用(yong)提供(gong)有(you)力保障。預測未來3年(nian)(nian),我國(guo)(guo)室溫硫化硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)在汽(qi)(qi)(qi)(qi)車(che)(che)行(xing)業(ye)將以年(nian)(nian)均(jun)20%增(zeng)長(chang)。
此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的(de)(de)(de)非石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約(yue)占非石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消費(fei)量的(de)(de)(de)98%。但因(yin)(yin)為(wei)石(shi)(shi)油(you)(you)價格的(de)(de)(de)大(da)幅上漲(zhang),同時(shi)我(wo)國(guo)在硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關鍵原料有(you)機(ji)硅(gui)(gui)單體的(de)(de)(de)生產技(ji)術方面取得突破,有(you)機(ji)硅(gui)(gui)單體的(de)(de)(de)生產技(ji)術在2005年(nian)前(qian)被幾家(jia)跨國(guo)公司壟斷(duan),但目前(qian)我(wo)國(guo)已(yi)發展成(cheng)(cheng)(cheng)為(wei)全球(qiu)有(you)機(ji)硅(gui)(gui)單體第(di)1大(da)國(guo),這2個方面原因(yin)(yin)使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價格從(cong)2011年(nian)起開始低于石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約(yue)為(wei)大(da)宗石(shi)(shi)油(you)(you)基橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉(lian)價的(de)(de)(de)合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始大(da)規(gui)模替代石(shi)(shi)油(you)(you)基合(he)(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)拓展有(you)機(ji)硅(gui)(gui)產業的(de)(de)(de)市場空間,同時(shi)將帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹(shu)脂等其他有(you)機(ji)硅(gui)(gui)產品的(de)(de)(de)消費(fei)。