硅橡膠是指主鏈由硅(gui)(gui)(gui)(gui)和氧(yang)原子交替構成,硅(gui)(gui)(gui)(gui)原子上(shang)通常連有(you)兩(liang)個有(you)機基團的(de)橡(xiang)(xiang)(xiang)(xiang)膠。普通的(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠主要(yao)由含甲基和少量乙烯基的(de)硅(gui)(gui)(gui)(gui)氧(yang)鏈節組成。苯(ben)基的(de)引(yin)(yin)入可(ke)提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)耐(nai)(nai)高(gao)、低溫性(xing)(xing)能(neng)(neng),三氟丙基及氰基的(de)引(yin)(yin)入則可(ke)提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)耐(nai)(nai)溫及耐(nai)(nai)油性(xing)(xing)能(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠耐(nai)(nai)低溫性(xing)(xing)能(neng)(neng)良好(hao),一(yi)般在-55℃下仍(reng)能(neng)(neng)工作。引(yin)(yin)入苯(ben)基后,可(ke)達(da)-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)耐(nai)(nai)熱性(xing)(xing)能(neng)(neng)也很突(tu)出(chu),在180℃下可(ke)長期工作,稍高(gao)于200℃也能(neng)(neng)承(cheng)受數周或(huo)更長時間仍(reng)有(you)彈性(xing)(xing),瞬時可(ke)耐(nai)(nai)300℃以上(shang)的(de)高(gao)溫。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠的(de)透氣(qi)性(xing)(xing)好(hao),氧(yang)氣(qi)透過率在合成聚(ju)合物中是較高(gao)的(de)。此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠還具(ju)有(you)生理惰性(xing)(xing)、不會導(dao)致凝血的(de)突(tu)出(chu)特性(xing)(xing),因此(ci)在醫用領域應用廣泛。
主要(yao)品種
硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類(lei)的(de)(de)方(fang)法很(hen)多,通(tong)常按(an)固(gu)化前的(de)(de)形態分(fen)為固(gu)體(ti)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和液體(ti)硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)硫(liu)(liu)化溫度分(fen)為室溫硫(liu)(liu)化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)溫硫(liu)(liu)化硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)所用單體(ti)的(de)(de)不同,可分(fen)為甲基乙烯基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲基苯基乙烯基硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng);按(an)性能(neng)和用途的(de)(de)不同又可分(fen)為通(tong)用型(xing)(xing)、超耐(nai)低溫型(xing)(xing)、超耐(nai)高(gao)溫型(xing)(xing)、高(gao)強力(li)型(xing)(xing)、耐(nai)油(you)型(xing)(xing)、醫用型(xing)(xing)等(deng)等(deng)。
發(fa)展史(shi)
硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由(you)美國(guo)以(yi)三氯化(hua)鐵為催化(hua)劑合成的(de)(de)。1945年(nian),硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)產(chan)(chan)品問世。1948年(nian),采(cai)用高比表面積(ji)的(de)(de)氣相法白炭黑補強(qiang)的(de)(de)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)研制(zhi)成功(gong),使硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)性能躍升到(dao)實(shi)用階段,奠定了(le)現(xian)代硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)(chan)技術的(de)(de)基(ji)礎。從二(er)甲基(ji)二(er)氯硅烷合成開(kai)始(shi)生產(chan)(chan)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)國(guo)家有美國(guo)。俄羅斯、德國(guo)、日本、韓(han)國(guo)和(he)中(zhong)國(guo)等。中(zhong)國(guo)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)工業化(hua)研究始(shi)于1957年(nian),多家研究所和(he)企業陸(lu)續開(kai)發出各種硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)國(guo)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)生產(chan)(chan)能力為135千噸(dun)(dun),其中(zhong)高溫膠(jiao)(jiao)(jiao)100千噸(dun)(dun)。
高溫硫化(hua)硅(gui)橡膠
高溫硫(liu)(liu)(liu)化(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao)是(shi)(shi)指聚(ju)硅(gui)氧烷變成彈(dan)性體(ti)的(de)(de)(de)過程是(shi)(shi)經過高溫(110-170℃)硫(liu)(liu)(liu)化(hua)(hua)成型(xing)的(de)(de)(de)。它主要(yao)以高分子量的(de)(de)(de)聚(ju)甲(jia)基(ji)乙(yi)烯(xi)基(ji)硅(gui)氧烷為生膠(jiao)(jiao),混入補強(qiang)填料、硫(liu)(liu)(liu)化(hua)(hua)劑等,在加(jia)(jia)熱(re)加(jia)(jia)壓下硫(liu)(liu)(liu)化(hua)(hua)成彈(dan)性體(ti)。硅(gui)橡(xiang)膠(jiao)(jiao)的(de)(de)(de)補強(qiang)主要(yao)是(shi)(shi)各種類型(xing)的(de)(de)(de)白(bai)炭黑,可使硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)(jiao)的(de)(de)(de)強(qiang)度(du)增加(jia)(jia)數十倍。有時為了降低成本或(huo)改善膠(jiao)(jiao)料性能及賦(fu)予硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)(jiao)各種特(te)殊的(de)(de)(de)性能,也(ye)加(jia)(jia)入相應的(de)(de)(de)各種添加(jia)(jia)劑。硫(liu)(liu)(liu)化(hua)(hua)劑是(shi)(shi)各種有機過氧化(hua)(hua)物或(huo)加(jia)(jia)成反應催化(hua)(hua)劑。
加工成型方(fang)法如(ru)圖所示。一次(ci)硫(liu)化的目(mu)的是(shi)進行(xing)(xing)高分子鏈的交聯反應;二次(ci)硫(liu)化的目(mu)的是(shi)進行(xing)(xing)補(bu)充交聯、驅除硫(liu)化劑分解產(chan)物和其他揮發性化合(he)物以穩定硫(liu)化膠(jiao)的各項(xiang)性能。常用的設(she)備(bei)有開放式煉(lian)膠(jiao)機(ji)、捏合(he)機(ji)及真空密(mi)煉(lian)機(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)特征(zheng)是高(gao)溫(wen)(wen)(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強(qiang)度(du)僅是天然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一(yi)半,但(dan)在(zai)200℃以上的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)環境(jing)下(xia),硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持一(yi)定(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面(mian)硬度(du),且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯變化(hua)(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻璃化(hua)(hua)溫(wen)(wen)(wen)(wen)度(du)一(yi)般為(wei)(wei)-70~-50℃,特殊配方可(ke)達-100℃,表(biao)明其低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對航空(kong)、宇航工(gong)業(ye)的(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)(yang)、臭氧(yang)(yang)及(ji)紫外線等十(shi)分(fen)穩(wen)定(ding),在(zai)不加任(ren)何添加劑的(de)(de)情況(kuang)下(xia),就具有(you)優良的(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)優異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)常好。(5)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)的(de)(de)物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)高(gao)溫(wen)(wen)(wen)(wen)和-50℃的(de)(de)低(di)溫(wen)(wen)(wen)(wen)下(xia),其物理(li)(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于(yu)通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及(ji)化(hua)(hua)學(xue)試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)中等的(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空(kong)氣(qi)(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)(hua)碳(tan)等氣(qi)(qi)體(ti)(ti)的(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生理(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅(xiu),與人體(ti)(ti)組織(zhi)不粘(zhan)連,具有(you)抗凝血作用,對肌體(ti)(ti)組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)常少。特別適合作為(wei)(wei)醫用材料。
硅橡膠的用量
據中國汽(qi)(qi)車(che)(che)工(gong)業(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)車(che)(che)產銷分(fen)別(bie)達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比(bi)分(fen)別(bie)增(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)車(che)(che)工(gong)業(ye)硅橡膠(jiao)的(de)(de)(de)(de)用(yong)量約達2.0萬(wan)t。根據觀研(yan)天下(xia)的(de)(de)(de)(de)新研(yan)究,增(zeng)加(jia)有(you)機硅材料在汽(qi)(qi)車(che)(che)零(ling)部件(jian)方面的(de)(de)(de)(de)用(yong)量,可以(yi)大(da)幅度(du)提高(gao)汽(qi)(qi)車(che)(che)的(de)(de)(de)(de)安全性能,因(yin)此,汽(qi)(qi)車(che)(che)產量和單車(che)(che)用(yong)量水平(ping)的(de)(de)(de)(de)提高(gao)都將推動汽(qi)(qi)車(che)(che)工(gong)業(ye)對硅橡膠(jiao)需求(qiu)的(de)(de)(de)(de)增(zeng)加(jia)。國家鼓(gu)勵自(zi)主(zhu)品(pin)(pin)牌的(de)(de)(de)(de)汽(qi)(qi)車(che)(che)發展,關(guan)鍵汽(qi)(qi)車(che)(che)零(ling)部件(jian)實現自(zi)主(zhu)化(hua),《2012年(nian)(nian)度(du)黨政機關(guan)公務用(yong)車(che)(che)選用(yong)車(che)(che)型目(mu)錄(征求(qiu)意見稿)》為(wei)(wei)自(zi)主(zhu)品(pin)(pin)牌擴大(da)在政府采購的(de)(de)(de)(de)市場份額,為(wei)(wei)改變(bian)目(mu)前國內政府采購以(yi)合資(zi)品(pin)(pin)牌產品(pin)(pin)為(wei)(wei)主(zhu)的(de)(de)(de)(de)局面提供了(le)保(bao)障(zhang)。促進(jin)自(zi)主(zhu)品(pin)(pin)牌發展,國產汽(qi)(qi)車(che)(che)業(ye)的(de)(de)(de)(de)繁榮將為(wei)(wei)汽(qi)(qi)車(che)(che)膠(jiao)的(de)(de)(de)(de)應用(yong)提供有(you)力保(bao)障(zhang)。預測未來3年(nian)(nian),我國室溫硫化(hua)硅橡膠(jiao)在汽(qi)(qi)車(che)(che)行業(ye)將以(yi)年(nian)(nian)均20%增(zeng)長(chang)。
此外,硅(gui)橡(xiang)(xiang)膠是重(zhong)要(yao)的(de)(de)非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)膠,約占(zhan)非(fei)石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)膠消(xiao)費量的(de)(de)98%。但因為(wei)石(shi)(shi)油(you)價格的(de)(de)大(da)幅(fu)上漲,同時我(wo)(wo)國(guo)在硅(gui)橡(xiang)(xiang)膠的(de)(de)關鍵(jian)原(yuan)料有機硅(gui)單體的(de)(de)生產技(ji)術(shu)(shu)方(fang)面取(qu)得(de)突破(po),有機硅(gui)單體的(de)(de)生產技(ji)術(shu)(shu)在2005年前(qian)被幾家跨國(guo)公(gong)司壟(long)斷(duan),但目前(qian)我(wo)(wo)國(guo)已(yi)發(fa)展成(cheng)為(wei)全球有機硅(gui)單體第1大(da)國(guo),這2個方(fang)面原(yuan)因使硅(gui)橡(xiang)(xiang)膠的(de)(de)價格從2011年起(qi)開始低于石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)膠,僅(jin)約為(wei)大(da)宗石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)膠的(de)(de)80%~90%,成(cheng)為(wei)廉價的(de)(de)合成(cheng)橡(xiang)(xiang)膠,并開始大(da)規模替代石(shi)(shi)油(you)基(ji)合成(cheng)橡(xiang)(xiang)膠。這將極大(da)拓展有機硅(gui)產業的(de)(de)市場空間,同時將帶動硅(gui)油(you)、硅(gui)烷偶聯劑和(he)硅(gui)樹脂(zhi)等其他有機硅(gui)產品(pin)的(de)(de)消(xiao)費。