硅橡膠是指主鏈由硅(gui)(gui)和氧(yang)原子交替(ti)構成(cheng),硅(gui)(gui)原子上通常連有兩個有機基(ji)團的(de)(de)(de)(de)(de)(de)(de)橡(xiang)(xiang)膠(jiao)。普通的(de)(de)(de)(de)(de)(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)和少量乙烯基(ji)的(de)(de)(de)(de)(de)(de)(de)硅(gui)(gui)氧(yang)鏈節組成(cheng)。苯(ben)基(ji)的(de)(de)(de)(de)(de)(de)(de)引入(ru)(ru)可(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)(de)(de)耐(nai)(nai)高、低溫(wen)性(xing)(xing)(xing)(xing)能,三氟丙基(ji)及(ji)氰基(ji)的(de)(de)(de)(de)(de)(de)(de)引入(ru)(ru)則可(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)(de)(de)耐(nai)(nai)溫(wen)及(ji)耐(nai)(nai)油(you)性(xing)(xing)(xing)(xing)能。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)耐(nai)(nai)低溫(wen)性(xing)(xing)(xing)(xing)能良(liang)好,一般(ban)在-55℃下(xia)仍(reng)能工(gong)作(zuo)。引入(ru)(ru)苯(ben)基(ji)后(hou),可(ke)(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)(de)(de)耐(nai)(nai)熱性(xing)(xing)(xing)(xing)能也很(hen)突出,在180℃下(xia)可(ke)(ke)長(chang)期(qi)工(gong)作(zuo),稍高于(yu)200℃也能承受數(shu)周或更(geng)長(chang)時間仍(reng)有彈(dan)性(xing)(xing)(xing)(xing),瞬時可(ke)(ke)耐(nai)(nai)300℃以上的(de)(de)(de)(de)(de)(de)(de)高溫(wen)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)(de)(de)透(tou)氣性(xing)(xing)(xing)(xing)好,氧(yang)氣透(tou)過率在合成(cheng)聚合物中是較高的(de)(de)(de)(de)(de)(de)(de)。此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)還具(ju)有生理惰性(xing)(xing)(xing)(xing)、不會導致凝血的(de)(de)(de)(de)(de)(de)(de)突出特性(xing)(xing)(xing)(xing),因此在醫用領域應用廣(guang)泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)分(fen)(fen)(fen)類的方(fang)法很多,通(tong)常(chang)按固(gu)化(hua)前的形態(tai)分(fen)(fen)(fen)為固(gu)體硅(gui)(gui)橡(xiang)膠(jiao)和(he)液體硅(gui)(gui)橡(xiang)膠(jiao);按硫(liu)化(hua)溫(wen)度分(fen)(fen)(fen)為室溫(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao),高溫(wen)硫(liu)化(hua)硅(gui)(gui)橡(xiang)膠(jiao);按所用單(dan)體的不(bu)同(tong),可分(fen)(fen)(fen)為甲(jia)基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao),甲(jia)基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)等(deng);按性能和(he)用途的不(bu)同(tong)又可分(fen)(fen)(fen)為通(tong)用型(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(yi)用型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由(you)美國(guo)(guo)以三氯化(hua)(hua)(hua)鐵為催化(hua)(hua)(hua)劑合成(cheng)的。1945年(nian)(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品問世。1948年(nian)(nian),采(cai)用(yong)高比(bi)表面積的氣(qi)相法白炭黑(hei)補強(qiang)的硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研(yan)制(zhi)成(cheng)功,使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的性能(neng)躍升到實(shi)用(yong)階段,奠定(ding)了現(xian)代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產技術(shu)的基礎。從二甲基二氯硅(gui)烷合成(cheng)開始生(sheng)產硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的國(guo)(guo)家有(you)美國(guo)(guo)。俄羅斯、德(de)國(guo)(guo)、日本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的工業化(hua)(hua)(hua)研(yan)究始于(yu)1957年(nian)(nian),多(duo)家研(yan)究所和企業陸續開發出各種硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年(nian)(nian)底,中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生(sheng)產能(neng)力為135千噸,其中(zhong)高溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)化(hua)硅橡膠(jiao)(jiao)(jiao)是(shi)指聚硅氧烷變(bian)成彈(dan)性(xing)(xing)體的過(guo)程是(shi)經(jing)過(guo)高溫(110-170℃)硫(liu)化(hua)成型(xing)的。它主要以高分(fen)子量的聚甲基乙烯基硅氧烷為(wei)生膠(jiao)(jiao)(jiao),混入補強填料(liao)、硫(liu)化(hua)劑等,在(zai)加(jia)熱加(jia)壓下硫(liu)化(hua)成彈(dan)性(xing)(xing)體。硅橡膠(jiao)(jiao)(jiao)的補強主要是(shi)各(ge)種(zhong)類型(xing)的白(bai)炭黑,可使硫(liu)化(hua)膠(jiao)(jiao)(jiao)的強度增(zeng)加(jia)數十(shi)倍。有(you)時(shi)為(wei)了降(jiang)低成本或(huo)改善(shan)膠(jiao)(jiao)(jiao)料(liao)性(xing)(xing)能及賦予(yu)硫(liu)化(hua)膠(jiao)(jiao)(jiao)各(ge)種(zhong)特殊的性(xing)(xing)能,也加(jia)入相應的各(ge)種(zhong)添加(jia)劑。硫(liu)化(hua)劑是(shi)各(ge)種(zhong)有(you)機過(guo)氧化(hua)物或(huo)加(jia)成反應催化(hua)劑。
加工(gong)成型(xing)方法(fa)如圖(tu)所(suo)示。一次硫(liu)化(hua)的(de)目(mu)的(de)是進(jin)行高(gao)分(fen)子鏈的(de)交聯(lian)反應;二次硫(liu)化(hua)的(de)目(mu)的(de)是進(jin)行補充交聯(lian)、驅除(chu)硫(liu)化(hua)劑(ji)分(fen)解產物和其他揮發(fa)性(xing)化(hua)合物以穩定硫(liu)化(hua)膠(jiao)的(de)各項(xiang)性(xing)能。常用的(de)設備(bei)有開放式煉(lian)膠(jiao)機、捏合機及真(zhen)空密煉(lian)機。
主要性能
(1)高溫(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著(zhu)的(de)(de)(de)(de)(de)特征是(shi)高溫(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強(qiang)度(du)僅是(shi)天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一(yi)半,但(dan)在200℃以上的(de)(de)(de)(de)(de)高溫(wen)環境下(xia)(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)保持一(yi)定的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du),且(qie)力學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無(wu)明(ming)(ming)顯(xian)變化。(2)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻(bo)璃化溫(wen)度(du)一(yi)般為-70~-50℃,特殊配方可(ke)達(da)-100℃,表明(ming)(ming)其(qi)低(di)溫(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)異。這對航空、宇(yu)航工(gong)業的(de)(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵對氧、臭氧及(ji)紫(zi)外線等十分穩(wen)定,在不加(jia)任何添加(jia)劑的(de)(de)(de)(de)(de)情況下(xia)(xia),就(jiu)具(ju)(ju)有(you)優(you)良的(de)(de)(de)(de)(de)耐(nai)(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)也(ye)非(fei)常(chang)好。(5)物理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)下(xia)(xia)的(de)(de)(de)(de)(de)物理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)(de)(de)高溫(wen)和(he)-50℃的(de)(de)(de)(de)(de)低(di)溫(wen)下(xia)(xia),其(qi)物理(li)機械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)于(yu)通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油及(ji)化學試劑性(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)中(zhong)等的(de)(de)(de)(de)(de)耐(nai)(nai)(nai)油、耐(nai)(nai)(nai)溶(rong)劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)下(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對空氣(qi)(qi)(qi)、氮、氧、二氧化碳等氣(qi)(qi)(qi)體(ti)的(de)(de)(de)(de)(de)透氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)組(zu)織不粘連,具(ju)(ju)有(you)抗(kang)凝血作用,對肌體(ti)組(zu)織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)非(fei)常(chang)少。特別適合作為醫用材料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)車(che)工(gong)業(ye)協(xie)會統計,2012年,汽(qi)(qi)車(che)產(chan)(chan)銷分(fen)別達到1927.18萬輛(liang)和1930.64萬輛(liang),同比分(fen)別增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)工(gong)業(ye)硅橡膠(jiao)的(de)(de)用(yong)量約達2.0萬t。根據觀(guan)研(yan)天下的(de)(de)新研(yan)究,增(zeng)加有機硅材(cai)料在汽(qi)(qi)車(che)零(ling)部(bu)件(jian)方面的(de)(de)用(yong)量,可以(yi)大幅度提(ti)高汽(qi)(qi)車(che)的(de)(de)安全性能,因此,汽(qi)(qi)車(che)產(chan)(chan)量和單車(che)用(yong)量水(shui)平的(de)(de)提(ti)高都將(jiang)推動汽(qi)(qi)車(che)工(gong)業(ye)對(dui)硅橡膠(jiao)需(xu)求的(de)(de)增(zeng)加。國(guo)(guo)家鼓勵自(zi)(zi)主(zhu)品(pin)(pin)牌的(de)(de)汽(qi)(qi)車(che)發(fa)展,關鍵(jian)汽(qi)(qi)車(che)零(ling)部(bu)件(jian)實現自(zi)(zi)主(zhu)化(hua),《2012年度黨政機關公務用(yong)車(che)選用(yong)車(che)型目(mu)(mu)錄(征(zheng)求意見稿)》為(wei)自(zi)(zi)主(zhu)品(pin)(pin)牌擴大在政府采購的(de)(de)市場份額,為(wei)改變(bian)目(mu)(mu)前國(guo)(guo)內政府采購以(yi)合資品(pin)(pin)牌產(chan)(chan)品(pin)(pin)為(wei)主(zhu)的(de)(de)局面提(ti)供(gong)了保障(zhang)。促進自(zi)(zi)主(zhu)品(pin)(pin)牌發(fa)展,國(guo)(guo)產(chan)(chan)汽(qi)(qi)車(che)業(ye)的(de)(de)繁榮將(jiang)為(wei)汽(qi)(qi)車(che)膠(jiao)的(de)(de)應用(yong)提(ti)供(gong)有力保障(zhang)。預(yu)測未來(lai)3年,我(wo)國(guo)(guo)室(shi)溫硫化(hua)硅橡膠(jiao)在汽(qi)(qi)車(che)行業(ye)將(jiang)以(yi)年均20%增(zeng)長。
此外(wai),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)是(shi)重要的非(fei)石(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao),約占非(fei)石(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)消費(fei)量的98%。但(dan)因為(wei)(wei)石(shi)油(you)價(jia)格的大(da)(da)幅上漲,同時我(wo)國(guo)在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的關鍵(jian)原(yuan)料有(you)機(ji)硅(gui)(gui)(gui)單(dan)體的生產(chan)技(ji)術(shu)方面取(qu)得(de)突(tu)破,有(you)機(ji)硅(gui)(gui)(gui)單(dan)體的生產(chan)技(ji)術(shu)在(zai)2005年(nian)前(qian)被幾(ji)家跨國(guo)公司壟斷,但(dan)目前(qian)我(wo)國(guo)已發展成(cheng)(cheng)(cheng)(cheng)(cheng)為(wei)(wei)全(quan)球有(you)機(ji)硅(gui)(gui)(gui)單(dan)體第1大(da)(da)國(guo),這(zhe)2個方面原(yuan)因使硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的價(jia)格從2011年(nian)起開始低于(yu)石(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao),僅約為(wei)(wei)大(da)(da)宗石(shi)油(you)基(ji)橡(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)(cheng)(cheng)(cheng)(cheng)為(wei)(wei)廉價(jia)的合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao),并開始大(da)(da)規模(mo)替(ti)代石(shi)油(you)基(ji)合成(cheng)(cheng)(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)。這(zhe)將極大(da)(da)拓展有(you)機(ji)硅(gui)(gui)(gui)產(chan)業的市場空間,同時將帶動(dong)硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷(wan)偶聯劑(ji)和(he)硅(gui)(gui)(gui)樹脂等其他有(you)機(ji)硅(gui)(gui)(gui)產(chan)品的消費(fei)。