硅橡膠是指主鏈由(you)硅(gui)(gui)(gui)(gui)和(he)(he)氧原子交替(ti)構成(cheng)(cheng),硅(gui)(gui)(gui)(gui)原子上(shang)通常連有(you)兩個(ge)有(you)機基(ji)(ji)團的(de)(de)橡(xiang)(xiang)膠。普通的(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠主要由(you)含甲(jia)基(ji)(ji)和(he)(he)少量乙烯基(ji)(ji)的(de)(de)硅(gui)(gui)(gui)(gui)氧鏈節組成(cheng)(cheng)。苯基(ji)(ji)的(de)(de)引(yin)(yin)入可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐高(gao)、低溫(wen)(wen)性能(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引(yin)(yin)入則可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐溫(wen)(wen)及耐油性能(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠耐低溫(wen)(wen)性能(neng)(neng)良好,一般(ban)在(zai)-55℃下仍能(neng)(neng)工作。引(yin)(yin)入苯基(ji)(ji)后,可達(da)-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)耐熱性能(neng)(neng)也很突出(chu),在(zai)180℃下可長期工作,稍(shao)高(gao)于200℃也能(neng)(neng)承(cheng)受數(shu)周(zhou)或更長時(shi)間仍有(you)彈性,瞬時(shi)可耐300℃以上(shang)的(de)(de)高(gao)溫(wen)(wen)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)透氣性好,氧氣透過(guo)率在(zai)合(he)成(cheng)(cheng)聚合(he)物中是較高(gao)的(de)(de)。此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠還具有(you)生理惰性、不會導致(zhi)凝血的(de)(de)突出(chu)特性,因此(ci)在(zai)醫用(yong)(yong)領域應用(yong)(yong)廣泛。
主要品種
硅(gui)橡膠(jiao)(jiao)分(fen)類(lei)的方法很多,通常按(an)固化(hua)前的形態分(fen)為固體(ti)(ti)硅(gui)橡膠(jiao)(jiao)和(he)液體(ti)(ti)硅(gui)橡膠(jiao)(jiao);按(an)硫化(hua)溫(wen)度分(fen)為室(shi)溫(wen)硫化(hua)硅(gui)橡膠(jiao)(jiao),高溫(wen)硫化(hua)硅(gui)橡膠(jiao)(jiao);按(an)所用單體(ti)(ti)的不(bu)同(tong),可分(fen)為甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡膠(jiao)(jiao),甲基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡膠(jiao)(jiao)等;按(an)性能和(he)用途的不(bu)同(tong)又可分(fen)為通用型、超耐低溫(wen)型、超耐高溫(wen)型、高強力型、耐油型、醫(yi)用型等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠早(zao)期(qi)是由美(mei)(mei)國(guo)以三氯化(hua)鐵為催化(hua)劑合成(cheng)的。1945年,硅(gui)(gui)(gui)橡(xiang)膠產(chan)品(pin)問世(shi)。1948年,采用高比表(biao)面積的氣相法白炭黑補強的硅(gui)(gui)(gui)橡(xiang)膠研制成(cheng)功,使(shi)硅(gui)(gui)(gui)橡(xiang)膠的性能躍升(sheng)到實(shi)用階段,奠定了現代硅(gui)(gui)(gui)橡(xiang)膠生產(chan)技(ji)術的基(ji)礎。從(cong)二甲基(ji)二氯硅(gui)(gui)(gui)烷合成(cheng)開(kai)始生產(chan)硅(gui)(gui)(gui)橡(xiang)膠的國(guo)家有美(mei)(mei)國(guo)。俄(e)羅斯、德國(guo)、日(ri)本、韓(han)國(guo)和中(zhong)(zhong)國(guo)等。中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠的工業化(hua)研究(jiu)始于1957年,多(duo)家研究(jiu)所和企業陸續開(kai)發出(chu)各種(zhong)硅(gui)(gui)(gui)橡(xiang)膠。到2003年底,中(zhong)(zhong)國(guo)硅(gui)(gui)(gui)橡(xiang)膠生產(chan)能力(li)為135千噸(dun),其(qi)中(zhong)(zhong)高溫(wen)膠100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)化(hua)硅(gui)橡膠(jiao)是(shi)(shi)指聚硅(gui)氧烷變(bian)成彈(dan)性體的(de)過程是(shi)(shi)經過高(gao)溫(wen)(110-170℃)硫(liu)化(hua)成型的(de)。它主(zhu)要以高(gao)分(fen)子量的(de)聚甲基(ji)乙烯基(ji)硅(gui)氧烷為(wei)生膠(jiao),混(hun)入(ru)補強填料、硫(liu)化(hua)劑(ji)(ji)等,在(zai)加(jia)熱加(jia)壓下硫(liu)化(hua)成彈(dan)性體。硅(gui)橡膠(jiao)的(de)補強主(zhu)要是(shi)(shi)各種類型的(de)白炭黑,可使硫(liu)化(hua)膠(jiao)的(de)強度增加(jia)數十倍。有時(shi)為(wei)了(le)降低成本或改善膠(jiao)料性能(neng)及賦予硫(liu)化(hua)膠(jiao)各種特殊的(de)性能(neng),也加(jia)入(ru)相應的(de)各種添加(jia)劑(ji)(ji)。硫(liu)化(hua)劑(ji)(ji)是(shi)(shi)各種有機(ji)過氧化(hua)物或加(jia)成反應催(cui)化(hua)劑(ji)(ji)。
加(jia)工(gong)成(cheng)型(xing)方法如(ru)圖所示(shi)。一(yi)次(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是(shi)進(jin)行高(gao)分子鏈的(de)(de)交聯反(fan)應;二次(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是(shi)進(jin)行補充交聯、驅(qu)除硫(liu)化(hua)劑分解(jie)產物(wu)和其(qi)他(ta)揮(hui)發(fa)性(xing)化(hua)合物(wu)以穩定硫(liu)化(hua)膠的(de)(de)各項性(xing)能。常用的(de)(de)設備有開放式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)強度(du)(du)僅是(shi)天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)一半,但(dan)在200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)環境下,硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)保持一定的(de)(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表(biao)(biao)面硬度(du)(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)無(wu)(wu)明(ming)顯(xian)變化(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)(de)玻璃化(hua)溫(wen)(wen)度(du)(du)一般為-70~-50℃,特(te)殊配方可達-100℃,表(biao)(biao)明(ming)其低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)異。這(zhe)對航(hang)空、宇航(hang)工業(ye)的(de)(de)(de)(de)(de)意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及紫外(wai)線等(deng)(deng)十分(fen)穩(wen)定,在不(bu)加任(ren)何添加劑的(de)(de)(de)(de)(de)情況下,就具(ju)(ju)有優(you)良的(de)(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有優(you)異的(de)(de)(de)(de)(de)絕(jue)緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好(hao)。(5)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下的(de)(de)(de)(de)(de)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)比通(tong)(tong)用(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)和(he)-50℃的(de)(de)(de)(de)(de)低(di)溫(wen)(wen)下,其物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)于通(tong)(tong)用(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及化(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)(tong)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有中等(deng)(deng)的(de)(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。(7)氣(qi)(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。室溫(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對空氣(qi)(qi)、氮、氧(yang)(yang)、二(er)氧(yang)(yang)化(hua)碳等(deng)(deng)氣(qi)(qi)體的(de)(de)(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍(bei)。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)(wu)毒,無(wu)(wu)味,無(wu)(wu)嗅(xiu),與人體組(zu)織不(bu)粘連,具(ju)(ju)有抗凝血作(zuo)用(yong)(yong),對肌體組(zu)織的(de)(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少。特(te)別適(shi)合(he)作(zuo)為醫用(yong)(yong)材料。
硅橡膠的用量
據(ju)中國(guo)(guo)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)協(xie)會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產銷分別(bie)達(da)到1927.18萬(wan)輛(liang)和(he)1930.64萬(wan)輛(liang),同比分別(bie)增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)硅橡膠(jiao)的用(yong)量約(yue)達(da)2.0萬(wan)t。根據(ju)觀(guan)研天下的新研究,增(zeng)加(jia)有機硅材(cai)料在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零部件方面(mian)的用(yong)量,可以大幅度(du)(du)提(ti)高(gao)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)的安全(quan)性能,因此,汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)產量和(he)單車(che)(che)(che)用(yong)量水平(ping)的提(ti)高(gao)都將推動汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)工(gong)業(ye)對硅橡膠(jiao)需求的增(zeng)加(jia)。國(guo)(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)牌(pai)的汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)發(fa)展(zhan),關鍵汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)零部件實現自(zi)主(zhu)化,《2012年(nian)(nian)度(du)(du)黨政機關公務(wu)用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目(mu)錄(征求意見稿)》為(wei)自(zi)主(zhu)品(pin)(pin)牌(pai)擴大在政府采(cai)購的市場份額(e),為(wei)改變(bian)目(mu)前國(guo)(guo)內政府采(cai)購以合資品(pin)(pin)牌(pai)產品(pin)(pin)為(wei)主(zhu)的局面(mian)提(ti)供(gong)了保障(zhang)。促進自(zi)主(zhu)品(pin)(pin)牌(pai)發(fa)展(zhan),國(guo)(guo)產汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)業(ye)的繁榮(rong)將為(wei)汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)膠(jiao)的應用(yong)提(ti)供(gong)有力保障(zhang)。預測未(wei)來3年(nian)(nian),我國(guo)(guo)室溫硫化硅橡膠(jiao)在汽(qi)(qi)(qi)(qi)(qi)車(che)(che)(che)行業(ye)將以年(nian)(nian)均20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的(de)(de)非石(shi)(shi)(shi)油基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,約占非石(shi)(shi)(shi)油基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠消(xiao)費量的(de)(de)98%。但(dan)因(yin)為(wei)(wei)石(shi)(shi)(shi)油價(jia)格的(de)(de)大(da)幅上漲,同(tong)時我國(guo)(guo)(guo)在(zai)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)關鍵原(yuan)料有(you)機硅(gui)(gui)(gui)(gui)單體(ti)(ti)的(de)(de)生產技術方面(mian)取(qu)得(de)突破,有(you)機硅(gui)(gui)(gui)(gui)單體(ti)(ti)的(de)(de)生產技術在(zai)2005年前被幾家(jia)跨(kua)國(guo)(guo)(guo)公司壟斷,但(dan)目前我國(guo)(guo)(guo)已發展成(cheng)(cheng)(cheng)為(wei)(wei)全球有(you)機硅(gui)(gui)(gui)(gui)單體(ti)(ti)第1大(da)國(guo)(guo)(guo),這2個方面(mian)原(yuan)因(yin)使硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)價(jia)格從2011年起開(kai)始低于石(shi)(shi)(shi)油基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,僅(jin)約為(wei)(wei)大(da)宗石(shi)(shi)(shi)油基(ji)橡(xiang)(xiang)膠的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)(wei)廉價(jia)的(de)(de)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠,并開(kai)始大(da)規模替代石(shi)(shi)(shi)油基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠。這將極(ji)大(da)拓展有(you)機硅(gui)(gui)(gui)(gui)產業的(de)(de)市場空(kong)間(jian),同(tong)時將帶(dai)動(dong)硅(gui)(gui)(gui)(gui)油、硅(gui)(gui)(gui)(gui)烷偶(ou)聯劑和硅(gui)(gui)(gui)(gui)樹(shu)脂等其(qi)他有(you)機硅(gui)(gui)(gui)(gui)產品(pin)的(de)(de)消(xiao)費。