硅橡膠是指主(zhu)(zhu)鏈(lian)由硅(gui)(gui)(gui)和氧原子(zi)交替構(gou)成(cheng)(cheng),硅(gui)(gui)(gui)原子(zi)上通(tong)(tong)常連有(you)兩個有(you)機(ji)基(ji)團的(de)(de)(de)橡(xiang)膠(jiao)。普通(tong)(tong)的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)主(zhu)(zhu)要由含甲基(ji)和少量乙烯(xi)基(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧鏈(lian)節組(zu)成(cheng)(cheng)。苯基(ji)的(de)(de)(de)引入可(ke)提高硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)高、低(di)溫(wen)性(xing)能(neng),三氟丙基(ji)及氰基(ji)的(de)(de)(de)引入則可(ke)提高硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)溫(wen)及耐(nai)油性(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)耐(nai)低(di)溫(wen)性(xing)能(neng)良好,一般(ban)在(zai)-55℃下(xia)仍能(neng)工作(zuo)。引入苯基(ji)后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)耐(nai)熱性(xing)能(neng)也(ye)很突出,在(zai)180℃下(xia)可(ke)長(chang)期工作(zuo),稍高于(yu)200℃也(ye)能(neng)承受數周或更長(chang)時(shi)間仍有(you)彈性(xing),瞬時(shi)可(ke)耐(nai)300℃以(yi)上的(de)(de)(de)高溫(wen)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)透氣性(xing)好,氧氣透過率(lv)在(zai)合(he)成(cheng)(cheng)聚合(he)物中是較高的(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)膠(jiao)還具有(you)生理惰性(xing)、不(bu)會(hui)導致(zhi)凝血的(de)(de)(de)突出特(te)性(xing),因(yin)此在(zai)醫用領(ling)域(yu)應(ying)用廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分類的(de)(de)方法很多,通常(chang)按(an)固化(hua)(hua)前的(de)(de)形態分為(wei)(wei)固體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液(ye)體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)硫化(hua)(hua)溫(wen)(wen)度分為(wei)(wei)室(shi)溫(wen)(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高(gao)溫(wen)(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)所用(yong)單體的(de)(de)不(bu)同,可(ke)分為(wei)(wei)甲基乙烯(xi)基硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基苯基乙烯(xi)基硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等;按(an)性能和用(yong)途(tu)的(de)(de)不(bu)同又可(ke)分為(wei)(wei)通用(yong)型(xing)(xing)、超耐(nai)低(di)溫(wen)(wen)型(xing)(xing)、超耐(nai)高(gao)溫(wen)(wen)型(xing)(xing)、高(gao)強(qiang)力型(xing)(xing)、耐(nai)油(you)型(xing)(xing)、醫用(yong)型(xing)(xing)等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)早期是由美國(guo)以三氯(lv)化鐵(tie)為(wei)催化劑合(he)成(cheng)(cheng)的。1945年(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)產(chan)品問世。1948年(nian),采用高(gao)比表(biao)面積(ji)的氣相法白(bai)炭黑補強的硅(gui)(gui)橡(xiang)膠(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的性能躍升到(dao)實用階(jie)段,奠定了現代(dai)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)技術的基礎。從二甲基二氯(lv)硅(gui)(gui)烷合(he)成(cheng)(cheng)開(kai)始生(sheng)(sheng)產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的國(guo)家有美國(guo)。俄(e)羅(luo)斯、德(de)國(guo)、日(ri)本、韓國(guo)和(he)中(zhong)(zhong)國(guo)等。中(zhong)(zhong)國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的工業化研(yan)究始于1957年(nian),多家研(yan)究所和(he)企業陸續開(kai)發(fa)出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)(zhong)國(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)生(sheng)(sheng)產(chan)能力為(wei)135千噸,其中(zhong)(zhong)高(gao)溫(wen)膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫硫(liu)化硅(gui)橡膠(jiao)(jiao)是(shi)(shi)指聚硅(gui)氧(yang)烷(wan)變成(cheng)彈性(xing)體的(de)過程是(shi)(shi)經過高(gao)溫(110-170℃)硫(liu)化成(cheng)型(xing)的(de)。它主要(yao)以(yi)高(gao)分(fen)子量(liang)的(de)聚甲基乙(yi)烯基硅(gui)氧(yang)烷(wan)為生膠(jiao)(jiao),混入(ru)補強填料(liao)、硫(liu)化劑等,在加(jia)熱加(jia)壓下硫(liu)化成(cheng)彈性(xing)體。硅(gui)橡膠(jiao)(jiao)的(de)補強主要(yao)是(shi)(shi)各(ge)(ge)種(zhong)類型(xing)的(de)白炭(tan)黑,可使硫(liu)化膠(jiao)(jiao)的(de)強度增(zeng)加(jia)數(shu)十(shi)倍。有(you)時為了降低成(cheng)本(ben)或改(gai)善膠(jiao)(jiao)料(liao)性(xing)能及賦予硫(liu)化膠(jiao)(jiao)各(ge)(ge)種(zhong)特殊的(de)性(xing)能,也(ye)加(jia)入(ru)相應(ying)(ying)的(de)各(ge)(ge)種(zhong)添(tian)加(jia)劑。硫(liu)化劑是(shi)(shi)各(ge)(ge)種(zhong)有(you)機過氧(yang)化物(wu)或加(jia)成(cheng)反(fan)應(ying)(ying)催化劑。
加工成型方法如圖(tu)所示。一次硫(liu)化(hua)(hua)的目的是進行高分(fen)子鏈的交(jiao)聯(lian)反應;二次硫(liu)化(hua)(hua)的目的是進行補充交(jiao)聯(lian)、驅除硫(liu)化(hua)(hua)劑分(fen)解產物和其他揮發性化(hua)(hua)合(he)物以穩定硫(liu)化(hua)(hua)膠(jiao)的各項性能(neng)。常(chang)用的設(she)備(bei)有(you)開放式煉膠(jiao)機、捏(nie)合(he)機及真空密煉機。
主要性能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)特(te)征是(shi)(shi)高溫(wen)(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常溫(wen)(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)強(qiang)度(du)(du)僅是(shi)(shi)天然橡(xiang)膠(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)一(yi)半,但在200℃以上的(de)(de)(de)(de)高溫(wen)(wen)(wen)環境下,硅橡(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度(du)(du),且力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明(ming)顯變化(hua)。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度(du)(du)一(yi)般為(wei)-70~-50℃,特(te)殊配方(fang)可達-100℃,表明(ming)其低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)異。這對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)(de)意義重大(da)。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)氧、臭氧及紫外線等(deng)(deng)十分穩(wen)定(ding),在不加任何添(tian)加劑的(de)(de)(de)(de)情況下,就具(ju)有(you)優(you)(you)良的(de)(de)(de)(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)優(you)(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐電(dian)暈(yun)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)(fei)常好。(5)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)下的(de)(de)(de)(de)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比(bi)通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)高溫(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)低(di)溫(wen)(wen)(wen)下,其物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)于通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)。(6)耐油及化(hua)學試(shi)劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅橡(xiang)膠(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)(deng)的(de)(de)(de)(de)耐油、耐溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧、二氧化(hua)碳等(deng)(deng)氣(qi)體(ti)的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然橡(xiang)膠(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與(yu)人體(ti)組(zu)織不粘連(lian),具(ju)有(you)抗凝血作(zuo)用(yong),對(dui)肌體(ti)組(zu)織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)(fei)常少。特(te)別適合作(zuo)為(wei)醫用(yong)材料。
硅橡膠的用量
據中國汽車(che)(che)(che)工(gong)業(ye)協(xie)會統(tong)計,2012年,汽車(che)(che)(che)產銷分別達(da)到1927.18萬(wan)輛(liang)和(he)(he)1930.64萬(wan)輛(liang),同比分別增(zeng)(zeng)長(chang)(chang)4.63%和(he)(he)4.33%,汽車(che)(che)(che)工(gong)業(ye)硅(gui)橡膠(jiao)的(de)(de)(de)(de)用(yong)(yong)量約達(da)2.0萬(wan)t。根據觀研天(tian)下的(de)(de)(de)(de)新研究,增(zeng)(zeng)加有機硅(gui)材料在汽車(che)(che)(che)零部(bu)(bu)件方面的(de)(de)(de)(de)用(yong)(yong)量,可以(yi)大幅度(du)提(ti)(ti)高汽車(che)(che)(che)的(de)(de)(de)(de)安全(quan)性(xing)能,因此,汽車(che)(che)(che)產量和(he)(he)單車(che)(che)(che)用(yong)(yong)量水平的(de)(de)(de)(de)提(ti)(ti)高都將(jiang)推動汽車(che)(che)(che)工(gong)業(ye)對(dui)硅(gui)橡膠(jiao)需(xu)求的(de)(de)(de)(de)增(zeng)(zeng)加。國家(jia)鼓勵自(zi)(zi)主(zhu)品(pin)(pin)牌的(de)(de)(de)(de)汽車(che)(che)(che)發展(zhan),關(guan)鍵汽車(che)(che)(che)零部(bu)(bu)件實(shi)現自(zi)(zi)主(zhu)化,《2012年度(du)黨政機關(guan)公(gong)務用(yong)(yong)車(che)(che)(che)選(xuan)用(yong)(yong)車(che)(che)(che)型目(mu)錄(征求意見稿(gao))》為自(zi)(zi)主(zhu)品(pin)(pin)牌擴大在政府(fu)采(cai)購的(de)(de)(de)(de)市場份額(e),為改變目(mu)前國內政府(fu)采(cai)購以(yi)合資品(pin)(pin)牌產品(pin)(pin)為主(zhu)的(de)(de)(de)(de)局(ju)面提(ti)(ti)供了保障。促進自(zi)(zi)主(zhu)品(pin)(pin)牌發展(zhan),國產汽車(che)(che)(che)業(ye)的(de)(de)(de)(de)繁榮(rong)將(jiang)為汽車(che)(che)(che)膠(jiao)的(de)(de)(de)(de)應用(yong)(yong)提(ti)(ti)供有力保障。預測未來3年,我國室溫(wen)硫化硅(gui)橡膠(jiao)在汽車(che)(che)(che)行業(ye)將(jiang)以(yi)年均20%增(zeng)(zeng)長(chang)(chang)。
此(ci)外,硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重要的(de)(de)非石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消費量的(de)(de)98%。但因(yin)為(wei)(wei)石(shi)(shi)油(you)價(jia)格的(de)(de)大幅上漲,同時(shi)我國(guo)(guo)在硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關鍵原料有(you)機(ji)硅(gui)單(dan)(dan)體的(de)(de)生產技術方(fang)面(mian)取得突破,有(you)機(ji)硅(gui)單(dan)(dan)體的(de)(de)生產技術在2005年前被(bei)幾家(jia)跨(kua)國(guo)(guo)公司(si)壟斷,但目前我國(guo)(guo)已(yi)發展(zhan)成(cheng)(cheng)為(wei)(wei)全球(qiu)有(you)機(ji)硅(gui)單(dan)(dan)體第1大國(guo)(guo),這(zhe)2個方(fang)面(mian)原因(yin)使硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價(jia)格從2011年起開(kai)始(shi)低于石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)(wei)大宗(zong)石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)為(wei)(wei)廉價(jia)的(de)(de)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開(kai)始(shi)大規模替代石(shi)(shi)油(you)基(ji)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將極大拓展(zhan)有(you)機(ji)硅(gui)產業的(de)(de)市場空間,同時(shi)將帶動(dong)硅(gui)油(you)、硅(gui)烷偶聯(lian)劑和硅(gui)樹脂等其他有(you)機(ji)硅(gui)產品的(de)(de)消費。