硅橡膠是(shi)指主鏈(lian)由硅(gui)(gui)(gui)和氧(yang)(yang)原子(zi)交(jiao)替構成,硅(gui)(gui)(gui)原子(zi)上(shang)通常(chang)連有(you)兩個有(you)機基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)膠。普通的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)(xiang)膠主要由含甲基(ji)(ji)和少量乙烯(xi)基(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧(yang)(yang)鏈(lian)節組成。苯基(ji)(ji)的(de)(de)(de)引入(ru)可(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐高(gao)(gao)(gao)、低(di)溫(wen)性(xing)(xing)能(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引入(ru)則可(ke)提(ti)高(gao)(gao)(gao)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐溫(wen)及耐油(you)性(xing)(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠耐低(di)溫(wen)性(xing)(xing)能(neng)良好,一(yi)般(ban)在-55℃下仍能(neng)工作。引入(ru)苯基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)耐熱性(xing)(xing)能(neng)也很突(tu)出,在180℃下可(ke)長期工作,稍高(gao)(gao)(gao)于(yu)200℃也能(neng)承受(shou)數周或(huo)更(geng)長時(shi)間仍有(you)彈性(xing)(xing),瞬時(shi)可(ke)耐300℃以(yi)上(shang)的(de)(de)(de)高(gao)(gao)(gao)溫(wen)。硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)(de)透(tou)氣(qi)(qi)性(xing)(xing)好,氧(yang)(yang)氣(qi)(qi)透(tou)過(guo)率(lv)在合(he)(he)成聚合(he)(he)物中是(shi)較高(gao)(gao)(gao)的(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠還具(ju)有(you)生理惰(duo)性(xing)(xing)、不會導致(zhi)凝血的(de)(de)(de)突(tu)出特性(xing)(xing),因此在醫用(yong)領域應用(yong)廣(guang)泛。
主要品種
硅(gui)橡(xiang)膠(jiao)(jiao)分(fen)(fen)類的(de)方法很(hen)多,通常(chang)按固化前的(de)形態分(fen)(fen)為固體(ti)硅(gui)橡(xiang)膠(jiao)(jiao)和(he)液體(ti)硅(gui)橡(xiang)膠(jiao)(jiao);按硫(liu)化溫(wen)(wen)(wen)度分(fen)(fen)為室溫(wen)(wen)(wen)硫(liu)化硅(gui)橡(xiang)膠(jiao)(jiao),高(gao)溫(wen)(wen)(wen)硫(liu)化硅(gui)橡(xiang)膠(jiao)(jiao);按所用(yong)單體(ti)的(de)不同(tong),可分(fen)(fen)為甲(jia)基乙(yi)烯(xi)基硅(gui)橡(xiang)膠(jiao)(jiao),甲(jia)基苯基乙(yi)烯(xi)基硅(gui)橡(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)膠(jiao)(jiao)等;按性能和(he)用(yong)途的(de)不同(tong)又可分(fen)(fen)為通用(yong)型(xing)(xing)、超耐低(di)溫(wen)(wen)(wen)型(xing)(xing)、超耐高(gao)溫(wen)(wen)(wen)型(xing)(xing)、高(gao)強力(li)型(xing)(xing)、耐油(you)型(xing)(xing)、醫(yi)用(yong)型(xing)(xing)等等。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)早期是由美(mei)(mei)國(guo)(guo)(guo)以(yi)三(san)氯化鐵為催(cui)化劑合成(cheng)的。1945年(nian),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)產品(pin)問世。1948年(nian),采用高(gao)(gao)比表(biao)面積的氣(qi)相法白炭黑補強的硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)研(yan)制成(cheng)功,使(shi)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的性能(neng)躍(yue)升到(dao)實用階段,奠定了現代硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產技術的基(ji)礎。從二甲基(ji)二氯硅(gui)烷(wan)合成(cheng)開始生產硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的國(guo)(guo)(guo)家有美(mei)(mei)國(guo)(guo)(guo)。俄羅(luo)斯、德(de)國(guo)(guo)(guo)、日本、韓(han)國(guo)(guo)(guo)和中國(guo)(guo)(guo)等(deng)。中國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的工業(ye)化研(yan)究(jiu)始于1957年(nian),多家研(yan)究(jiu)所(suo)和企業(ye)陸續開發出各種硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中國(guo)(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)生產能(neng)力為135千噸,其中高(gao)(gao)溫膠(jiao)(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫化(hua)硅橡膠(jiao)是(shi)指聚硅氧(yang)烷(wan)變成(cheng)彈性體的過程是(shi)經過高溫(110-170℃)硫化(hua)成(cheng)型的。它(ta)主要(yao)以高分子量的聚甲(jia)基(ji)乙烯基(ji)硅氧(yang)烷(wan)為生膠(jiao),混(hun)入補強填料、硫化(hua)劑等,在加熱(re)加壓(ya)下硫化(hua)成(cheng)彈性體。硅橡膠(jiao)的補強主要(yao)是(shi)各種(zhong)類型的白炭(tan)黑,可(ke)使(shi)硫化(hua)膠(jiao)的強度增加數十倍(bei)。有時為了(le)降低成(cheng)本(ben)或改(gai)善膠(jiao)料性能(neng)及賦予(yu)硫化(hua)膠(jiao)各種(zhong)特殊的性能(neng),也加入相應(ying)的各種(zhong)添加劑。硫化(hua)劑是(shi)各種(zhong)有機過氧(yang)化(hua)物或加成(cheng)反應(ying)催(cui)化(hua)劑。
加(jia)工成型(xing)方法如圖所示。一次(ci)硫化的(de)目(mu)的(de)是(shi)進行高(gao)分子(zi)鏈(lian)的(de)交聯反應;二次(ci)硫化的(de)目(mu)的(de)是(shi)進行補(bu)充交聯、驅除硫化劑分解產物和其(qi)他揮發性化合物以穩定硫化膠的(de)各項性能。常用(yong)的(de)設備有開放式煉(lian)膠機(ji)(ji)(ji)、捏合機(ji)(ji)(ji)及真空密煉(lian)機(ji)(ji)(ji)。
主要性能
(1)高(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)顯著的(de)(de)特(te)征是高(gao)溫(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)(chang)溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)強度僅(jin)是天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)一(yi)半,但(dan)在200℃以(yi)上的(de)(de)高(gao)溫(wen)(wen)環境下(xia)(xia),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持一(yi)定(ding)(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且(qie)力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明顯變化。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)(de)玻璃(li)化溫(wen)(wen)度一(yi)般(ban)為-70~-50℃,特(te)殊(shu)配方可達-100℃,表明其低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)異(yi)。這對(dui)(dui)航(hang)空、宇航(hang)工業的(de)(de)意(yi)義重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)中(zhong)Si-O-Si鍵對(dui)(dui)氧(yang)、臭氧(yang)及紫外(wai)線等(deng)十分(fen)穩定(ding)(ding),在不加(jia)任(ren)何添加(jia)劑的(de)(de)情況下(xia)(xia),就具(ju)有(you)優(you)良的(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)優(you)異(yi)的(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)常(chang)(chang)溫(wen)(wen)下(xia)(xia)的(de)(de)物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比(bi)通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)差,但(dan)在150℃的(de)(de)高(gao)溫(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)下(xia)(xia),其物理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)于通(tong)用橡(xiang)(xiang)膠(jiao)(jiao)。(6)耐油及化學(xue)試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)中(zhong)等(deng)的(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣(qi)、氮、氧(yang)、二氧(yang)化碳(tan)等(deng)氣(qi)體的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組織(zhi)不粘連,具(ju)有(you)抗凝血(xue)作用,對(dui)(dui)肌體組織(zhi)的(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少(shao)。特(te)別適(shi)合作為醫(yi)用材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)(che)工(gong)業協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)(che)產銷分別(bie)(bie)達到1927.18萬輛(liang)和1930.64萬輛(liang),同(tong)比分別(bie)(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)(qi)車(che)(che)工(gong)業硅橡(xiang)膠的(de)(de)用(yong)(yong)量約達2.0萬t。根據觀研天下(xia)的(de)(de)新(xin)研究,增(zeng)加(jia)有機硅材料在汽(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件(jian)方面(mian)的(de)(de)用(yong)(yong)量,可以大(da)幅度提(ti)高(gao)汽(qi)(qi)(qi)車(che)(che)的(de)(de)安全性能,因此,汽(qi)(qi)(qi)車(che)(che)產量和單車(che)(che)用(yong)(yong)量水平的(de)(de)提(ti)高(gao)都將(jiang)推動汽(qi)(qi)(qi)車(che)(che)工(gong)業對硅橡(xiang)膠需求的(de)(de)增(zeng)加(jia)。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)的(de)(de)汽(qi)(qi)(qi)車(che)(che)發展(zhan),關鍵(jian)汽(qi)(qi)(qi)車(che)(che)零(ling)部(bu)件(jian)實現自(zi)主(zhu)化,《2012年(nian)度黨政(zheng)機關公務用(yong)(yong)車(che)(che)選用(yong)(yong)車(che)(che)型目錄(征求意見稿)》為(wei)(wei)自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)擴大(da)在政(zheng)府采(cai)購(gou)的(de)(de)市場份額(e),為(wei)(wei)改變目前國(guo)內政(zheng)府采(cai)購(gou)以合資品(pin)(pin)(pin)牌(pai)產品(pin)(pin)(pin)為(wei)(wei)主(zhu)的(de)(de)局面(mian)提(ti)供了保障(zhang)(zhang)。促進自(zi)主(zhu)品(pin)(pin)(pin)牌(pai)發展(zhan),國(guo)產汽(qi)(qi)(qi)車(che)(che)業的(de)(de)繁榮(rong)將(jiang)為(wei)(wei)汽(qi)(qi)(qi)車(che)(che)膠的(de)(de)應(ying)用(yong)(yong)提(ti)供有力保障(zhang)(zhang)。預測未來3年(nian),我國(guo)室(shi)溫硫(liu)化硅橡(xiang)膠在汽(qi)(qi)(qi)車(che)(che)行(xing)業將(jiang)以年(nian)均20%增(zeng)長。
此外(wai),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)是重要的(de)(de)(de)(de)非石(shi)(shi)(shi)油(you)(you)(you)基(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao),約占非石(shi)(shi)(shi)油(you)(you)(you)基(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)消(xiao)費量的(de)(de)(de)(de)98%。但(dan)因為石(shi)(shi)(shi)油(you)(you)(you)價(jia)格(ge)的(de)(de)(de)(de)大(da)幅(fu)上漲,同(tong)時我(wo)國在硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)關鍵原料有(you)機硅(gui)(gui)單(dan)(dan)體(ti)(ti)(ti)的(de)(de)(de)(de)生(sheng)產(chan)技(ji)術方面取得突破,有(you)機硅(gui)(gui)單(dan)(dan)體(ti)(ti)(ti)的(de)(de)(de)(de)生(sheng)產(chan)技(ji)術在2005年(nian)前被幾(ji)家跨(kua)國公(gong)司壟斷,但(dan)目前我(wo)國已(yi)發展成為全球(qiu)有(you)機硅(gui)(gui)單(dan)(dan)體(ti)(ti)(ti)第1大(da)國,這(zhe)2個(ge)方面原因使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)價(jia)格(ge)從2011年(nian)起開始低于石(shi)(shi)(shi)油(you)(you)(you)基(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao),僅約為大(da)宗石(shi)(shi)(shi)油(you)(you)(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)80%~90%,成為廉價(jia)的(de)(de)(de)(de)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao),并(bing)開始大(da)規模(mo)替代(dai)石(shi)(shi)(shi)油(you)(you)(you)基(ji)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)。這(zhe)將極大(da)拓(tuo)展有(you)機硅(gui)(gui)產(chan)業的(de)(de)(de)(de)市(shi)場(chang)空間,同(tong)時將帶動硅(gui)(gui)油(you)(you)(you)、硅(gui)(gui)烷偶(ou)聯劑和硅(gui)(gui)樹脂等其他有(you)機硅(gui)(gui)產(chan)品的(de)(de)(de)(de)消(xiao)費。