硅橡膠是指主(zhu)鏈(lian)由硅(gui)(gui)(gui)(gui)和氧(yang)原子交替構成,硅(gui)(gui)(gui)(gui)原子上(shang)(shang)通(tong)常(chang)連有兩個有機基(ji)(ji)團的(de)(de)橡(xiang)膠(jiao)(jiao)。普(pu)通(tong)的(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)主(zhu)要由含甲基(ji)(ji)和少量乙烯(xi)基(ji)(ji)的(de)(de)硅(gui)(gui)(gui)(gui)氧(yang)鏈(lian)節組成。苯基(ji)(ji)的(de)(de)引(yin)入(ru)可提高(gao)(gao)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)高(gao)(gao)、低溫性(xing)(xing)(xing)能(neng),三氟丙(bing)基(ji)(ji)及氰基(ji)(ji)的(de)(de)引(yin)入(ru)則(ze)可提高(gao)(gao)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)溫及耐(nai)(nai)油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)耐(nai)(nai)低溫性(xing)(xing)(xing)能(neng)良好,一般在(zai)-55℃下仍能(neng)工作(zuo)。引(yin)入(ru)苯基(ji)(ji)后,可達-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)耐(nai)(nai)熱(re)性(xing)(xing)(xing)能(neng)也很突(tu)出,在(zai)180℃下可長期工作(zuo),稍高(gao)(gao)于200℃也能(neng)承受數(shu)周或更(geng)長時間仍有彈性(xing)(xing)(xing),瞬時可耐(nai)(nai)300℃以上(shang)(shang)的(de)(de)高(gao)(gao)溫。硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)透氣性(xing)(xing)(xing)好,氧(yang)氣透過率在(zai)合成聚合物中是較(jiao)高(gao)(gao)的(de)(de)。此外(wai),硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)還具有生(sheng)理(li)惰性(xing)(xing)(xing)、不會導致凝(ning)血的(de)(de)突(tu)出特性(xing)(xing)(xing),因(yin)此在(zai)醫用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分(fen)類的(de)方法很(hen)多,通常按固化(hua)(hua)前的(de)形態分(fen)為(wei)固體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液(ye)體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按硫化(hua)(hua)溫度分(fen)為(wei)室(shi)溫硫化(hua)(hua)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)溫硫化(hua)(hua)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按所用單體的(de)不同,可分(fen)為(wei)甲基乙烯(xi)基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基苯(ben)基乙烯(xi)基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui)(gui)(gui),腈硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等(deng);按性能和用途(tu)的(de)不同又(you)可分(fen)為(wei)通用型、超(chao)耐(nai)低溫型、超(chao)耐(nai)高(gao)溫型、高(gao)強力型、耐(nai)油(you)型、醫(yi)用型等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期是(shi)由美(mei)(mei)國(guo)(guo)以三氯化鐵為催化劑(ji)合成的。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產(chan)品(pin)問世。1948年,采用(yong)高比表面積(ji)的氣相法白炭(tan)黑補強(qiang)的硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研制成功,使(shi)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性能躍升到實用(yong)階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)技術的基礎。從二(er)甲基二(er)氯硅(gui)(gui)烷合成開始生(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國(guo)(guo)家有美(mei)(mei)國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日本、韓國(guo)(guo)和中國(guo)(guo)等(deng)。中國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業化研究(jiu)始于1957年,多家研究(jiu)所(suo)和企業陸(lu)續開發出各種(zhong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年底,中國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)能力為135千噸(dun),其(qi)中高溫膠(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)化(hua)(hua)硅(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)氧(yang)烷變成(cheng)(cheng)彈(dan)性體(ti)的(de)(de)過程(cheng)是(shi)(shi)經過高(gao)溫(110-170℃)硫(liu)化(hua)(hua)成(cheng)(cheng)型(xing)的(de)(de)。它主(zhu)(zhu)要以高(gao)分子(zi)量的(de)(de)聚甲基乙烯基硅(gui)氧(yang)烷為生膠(jiao)(jiao),混入(ru)補強填料(liao)、硫(liu)化(hua)(hua)劑(ji)(ji)(ji)等,在(zai)加(jia)熱加(jia)壓下硫(liu)化(hua)(hua)成(cheng)(cheng)彈(dan)性體(ti)。硅(gui)橡膠(jiao)(jiao)的(de)(de)補強主(zhu)(zhu)要是(shi)(shi)各種(zhong)(zhong)類型(xing)的(de)(de)白(bai)炭黑,可使(shi)硫(liu)化(hua)(hua)膠(jiao)(jiao)的(de)(de)強度增加(jia)數十倍。有時為了降低成(cheng)(cheng)本或(huo)改善(shan)膠(jiao)(jiao)料(liao)性能(neng)及賦予硫(liu)化(hua)(hua)膠(jiao)(jiao)各種(zhong)(zhong)特殊的(de)(de)性能(neng),也加(jia)入(ru)相(xiang)應的(de)(de)各種(zhong)(zhong)添加(jia)劑(ji)(ji)(ji)。硫(liu)化(hua)(hua)劑(ji)(ji)(ji)是(shi)(shi)各種(zhong)(zhong)有機(ji)過氧(yang)化(hua)(hua)物或(huo)加(jia)成(cheng)(cheng)反應催化(hua)(hua)劑(ji)(ji)(ji)。
加(jia)工成(cheng)型(xing)方法如(ru)圖(tu)所(suo)示。一次(ci)硫化(hua)的目的是進行高分子鏈的交聯反應;二次(ci)硫化(hua)的目的是進行補充交聯、驅除硫化(hua)劑分解(jie)產物和其他揮發性化(hua)合物以穩定硫化(hua)膠的各項性能。常(chang)用的設備(bei)有開放(fang)式(shi)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)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特征是高(gao)溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing),雖(sui)然(ran)常溫(wen)(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強(qiang)度(du)僅是天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某些(xie)合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在(zai)(zai)200℃以(yi)上(shang)的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)保持一定的(de)(de)(de)柔韌性(xing)(xing)(xing)、回彈性(xing)(xing)(xing)和(he)表(biao)(biao)面(mian)硬度(du),且力學(xue)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明(ming)(ming)顯變化(hua)。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)(wen)度(du)一般(ban)為(wei)-70~-50℃,特殊(shu)配方可達(da)-100℃,表(biao)(biao)明(ming)(ming)其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)異。這對(dui)航空、宇航工(gong)業(ye)的(de)(de)(de)意義重大(da)。(3)耐(nai)候性(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及紫(zi)外線(xian)等(deng)(deng)十分穩(wen)定,在(zai)(zai)不加任何(he)添加劑(ji)的(de)(de)(de)情況(kuang)下,就具(ju)(ju)有(you)優(you)良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)。(4)電(dian)(dian)氣性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)絕緣性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)電(dian)(dian)暈性(xing)(xing)(xing)和(he)耐(nai)電(dian)(dian)弧性(xing)(xing)(xing)也非常好。(5)物(wu)理機(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下的(de)(de)(de)物(wu)理機(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)下,其物(wu)理機(ji)械性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)于通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及化(hua)學(xue)試劑(ji)性(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)中等(deng)(deng)的(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣體(ti)透過性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣、氮、氧(yang)、二(er)氧(yang)化(hua)碳等(deng)(deng)氣體(ti)的(de)(de)(de)透氣性(xing)(xing)(xing)比天然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出(chu)30-50倍。(8)生(sheng)理惰(duo)性(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體(ti)組織(zhi)不粘連,具(ju)(ju)有(you)抗凝血作用(yong),對(dui)肌體(ti)組織(zhi)的(de)(de)(de)反(fan)應性(xing)(xing)(xing)非常少。特別適合作為(wei)醫(yi)用(yong)材料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)(qi)車工(gong)(gong)業協會統計,2012年(nian)(nian),汽(qi)(qi)(qi)(qi)車產(chan)銷(xiao)分別達到(dao)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)車工(gong)(gong)業硅(gui)橡(xiang)膠(jiao)的(de)用量(liang)約達2.0萬t。根據觀研(yan)(yan)天下的(de)新(xin)研(yan)(yan)究,增(zeng)加(jia)(jia)有(you)機硅(gui)材(cai)料(liao)在汽(qi)(qi)(qi)(qi)車零部件方面(mian)的(de)用量(liang),可(ke)以(yi)大幅度提(ti)(ti)高汽(qi)(qi)(qi)(qi)車的(de)安全性能,因此(ci),汽(qi)(qi)(qi)(qi)車產(chan)量(liang)和(he)單車用量(liang)水(shui)平(ping)的(de)提(ti)(ti)高都將(jiang)推動汽(qi)(qi)(qi)(qi)車工(gong)(gong)業對硅(gui)橡(xiang)膠(jiao)需求(qiu)的(de)增(zeng)加(jia)(jia)。國家鼓(gu)勵自(zi)主品(pin)牌的(de)汽(qi)(qi)(qi)(qi)車發展,關鍵汽(qi)(qi)(qi)(qi)車零部件實現自(zi)主化,《2012年(nian)(nian)度黨(dang)政機關公務用車選用車型(xing)目(mu)錄(征(zheng)求(qiu)意見稿)》為(wei)(wei)自(zi)主品(pin)牌擴大在政府(fu)采購(gou)的(de)市場份(fen)額,為(wei)(wei)改變目(mu)前(qian)國內政府(fu)采購(gou)以(yi)合資品(pin)牌產(chan)品(pin)為(wei)(wei)主的(de)局面(mian)提(ti)(ti)供(gong)了保(bao)(bao)障。促進(jin)自(zi)主品(pin)牌發展,國產(chan)汽(qi)(qi)(qi)(qi)車業的(de)繁(fan)榮將(jiang)為(wei)(wei)汽(qi)(qi)(qi)(qi)車膠(jiao)的(de)應用提(ti)(ti)供(gong)有(you)力保(bao)(bao)障。預(yu)測未來3年(nian)(nian),我(wo)國室(shi)溫(wen)硫化硅(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)(qi)車行業將(jiang)以(yi)年(nian)(nian)均(jun)20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的(de)(de)非石(shi)油基(ji)(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)油基(ji)(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消費量的(de)(de)98%。但(dan)因為(wei)石(shi)油價格的(de)(de)大幅上(shang)漲,同(tong)時我國(guo)在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關鍵原料(liao)有機硅(gui)(gui)(gui)單體(ti)的(de)(de)生(sheng)(sheng)產技術(shu)方面取得(de)突破(po),有機硅(gui)(gui)(gui)單體(ti)的(de)(de)生(sheng)(sheng)產技術(shu)在(zai)2005年(nian)前被幾家跨國(guo)公司壟斷,但(dan)目前我國(guo)已發展成(cheng)(cheng)為(wei)全(quan)球有機硅(gui)(gui)(gui)單體(ti)第1大國(guo),這(zhe)2個方面原因使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價格從2011年(nian)起開(kai)始低于石(shi)油基(ji)(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大宗石(shi)油基(ji)(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)廉價的(de)(de)合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開(kai)始大規(gui)模替代石(shi)油基(ji)(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將極大拓(tuo)展有機硅(gui)(gui)(gui)產業的(de)(de)市(shi)場空間,同(tong)時將帶動硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹脂等其他有機硅(gui)(gui)(gui)產品的(de)(de)消費。