硅橡膠是指主鏈(lian)由(you)硅(gui)(gui)(gui)和氧(yang)(yang)原子(zi)交替(ti)構成(cheng),硅(gui)(gui)(gui)原子(zi)上(shang)(shang)通常連有(you)兩(liang)個有(you)機基(ji)(ji)團的(de)(de)(de)(de)橡(xiang)膠(jiao)。普通的(de)(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)主要由(you)含甲(jia)基(ji)(ji)和少量(liang)乙烯基(ji)(ji)的(de)(de)(de)(de)硅(gui)(gui)(gui)氧(yang)(yang)鏈(lian)節組成(cheng)。苯(ben)基(ji)(ji)的(de)(de)(de)(de)引入可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐高(gao)、低溫性能(neng)(neng),三氟丙基(ji)(ji)及(ji)氰基(ji)(ji)的(de)(de)(de)(de)引入則可(ke)提高(gao)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐溫及(ji)耐油性能(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)耐低溫性能(neng)(neng)良好,一般(ban)在(zai)-55℃下仍(reng)(reng)能(neng)(neng)工作。引入苯(ben)基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)耐熱性能(neng)(neng)也很突出,在(zai)180℃下可(ke)長(chang)期工作,稍(shao)高(gao)于200℃也能(neng)(neng)承(cheng)受數周或更長(chang)時間仍(reng)(reng)有(you)彈性,瞬時可(ke)耐300℃以上(shang)(shang)的(de)(de)(de)(de)高(gao)溫。硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)(de)透氣(qi)性好,氧(yang)(yang)氣(qi)透過(guo)率在(zai)合成(cheng)聚合物中(zhong)是較高(gao)的(de)(de)(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)膠(jiao)還具有(you)生(sheng)理(li)惰(duo)性、不(bu)會導致凝血(xue)的(de)(de)(de)(de)突出特性,因此在(zai)醫用領域應用廣泛(fan)。
主要品種
硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類(lei)的(de)方法很多,通(tong)常(chang)按(an)固化前的(de)形態(tai)分(fen)為(wei)固體硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和(he)液體硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)硫化溫度分(fen)為(wei)室(shi)溫硫化硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高(gao)溫硫化硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)所用(yong)單體的(de)不同,可分(fen)為(wei)甲(jia)(jia)基(ji)乙烯基(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲(jia)(jia)基(ji)苯基(ji)乙烯基(ji)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅,腈(jing)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等;按(an)性能和(he)用(yong)途(tu)的(de)不同又可分(fen)為(wei)通(tong)用(yong)型、超(chao)耐(nai)低溫型、超(chao)耐(nai)高(gao)溫型、高(gao)強(qiang)力型、耐(nai)油型、醫用(yong)型等等。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)早期(qi)是由(you)美國以(yi)三氯化鐵為催(cui)化劑合成的。1945年(nian)(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)產(chan)品問世。1948年(nian)(nian),采用(yong)高(gao)比表(biao)面積(ji)的氣(qi)相法白炭黑補強的硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)研制成功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的性能躍升(sheng)到(dao)實用(yong)階(jie)段,奠(dian)定了現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)生(sheng)產(chan)技(ji)術的基(ji)礎。從二(er)甲基(ji)二(er)氯硅(gui)(gui)烷合成開始(shi)(shi)生(sheng)產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的國家有(you)美國。俄羅(luo)斯、德國、日本、韓國和中(zhong)國等。中(zhong)國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的工(gong)業(ye)化研究(jiu)始(shi)(shi)于1957年(nian)(nian),多家研究(jiu)所和企業(ye)陸續開發出各(ge)種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。到(dao)2003年(nian)(nian)底(di),中(zhong)國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)生(sheng)產(chan)能力為135千噸(dun),其中(zhong)高(gao)溫膠(jiao)(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫(liu)(liu)(liu)化(hua)(hua)硅(gui)橡膠(jiao)是指聚硅(gui)氧(yang)烷變(bian)成(cheng)彈(dan)性(xing)體的(de)(de)過(guo)程是經(jing)過(guo)高(gao)溫(110-170℃)硫(liu)(liu)(liu)化(hua)(hua)成(cheng)型(xing)的(de)(de)。它主(zhu)要(yao)以(yi)高(gao)分子(zi)量的(de)(de)聚甲基(ji)乙烯基(ji)硅(gui)氧(yang)烷為生膠(jiao),混入補(bu)強填料、硫(liu)(liu)(liu)化(hua)(hua)劑等,在加(jia)熱加(jia)壓(ya)下硫(liu)(liu)(liu)化(hua)(hua)成(cheng)彈(dan)性(xing)體。硅(gui)橡膠(jiao)的(de)(de)補(bu)強主(zhu)要(yao)是各種(zhong)(zhong)類型(xing)的(de)(de)白炭黑(hei),可(ke)使硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)的(de)(de)強度(du)增加(jia)數十(shi)倍。有時為了降低成(cheng)本(ben)或(huo)改善膠(jiao)料性(xing)能及賦予硫(liu)(liu)(liu)化(hua)(hua)膠(jiao)各種(zhong)(zhong)特殊(shu)的(de)(de)性(xing)能,也(ye)加(jia)入相應的(de)(de)各種(zhong)(zhong)添(tian)加(jia)劑。硫(liu)(liu)(liu)化(hua)(hua)劑是各種(zhong)(zhong)有機過(guo)氧(yang)化(hua)(hua)物或(huo)加(jia)成(cheng)反應催化(hua)(hua)劑。
加(jia)工成型方法如圖所示(shi)。一次(ci)(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是(shi)進行高分子鏈的(de)(de)交聯(lian)反(fan)應;二次(ci)(ci)硫(liu)化(hua)的(de)(de)目的(de)(de)是(shi)進行補充交聯(lian)、驅(qu)除硫(liu)化(hua)劑分解(jie)產物和其他揮(hui)發性化(hua)合物以穩定硫(liu)化(hua)膠的(de)(de)各項性能。常用的(de)(de)設備(bei)有(you)開放式煉(lian)膠機(ji)、捏合機(ji)及真空密(mi)煉(lian)機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)特(te)(te)征是高溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)強度僅是天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)一半(ban),但(dan)在(zai)200℃以上(shang)的(de)(de)高溫(wen)(wen)(wen)環境下(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一定的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬(ying)度,且(qie)力學(xue)(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明顯(xian)變化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)玻璃(li)化(hua)溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)(te)殊配方(fang)可達-100℃,表(biao)明其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對航(hang)空、宇航(hang)工業的(de)(de)意義重大(da)。(3)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中(zhong)Si-O-Si鍵(jian)對氧(yang)、臭氧(yang)及(ji)紫外線等十分穩定,在(zai)不(bu)加(jia)任(ren)何添(tian)加(jia)劑(ji)的(de)(de)情況下(xia),就具(ju)有(you)(you)(you)優(you)良的(de)(de)耐候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)(you)(you)優(you)異的(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐電(dian)(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物(wu)理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)的(de)(de)物(wu)理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的(de)(de)高溫(wen)(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)(wen)下(xia),其物(wu)理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通用橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐油及(ji)化(hua)學(xue)(xue)試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)有(you)(you)(you)中(zhong)等的(de)(de)耐油、耐溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)、氮、氧(yang)、二氧(yang)化(hua)碳等氣(qi)體(ti)(ti)的(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與人體(ti)(ti)組織不(bu)粘連,具(ju)有(you)(you)(you)抗凝血作用,對肌體(ti)(ti)組織的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少(shao)。特(te)(te)別適合作為醫用材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)工(gong)業(ye)協會統(tong)計,2012年(nian)(nian),汽(qi)(qi)車(che)產(chan)銷分別達到1927.18萬輛(liang)和(he)1930.64萬輛(liang),同(tong)比分別增(zeng)長4.63%和(he)4.33%,汽(qi)(qi)車(che)工(gong)業(ye)硅(gui)(gui)(gui)橡膠(jiao)(jiao)的用(yong)量(liang)(liang)(liang)(liang)約達2.0萬t。根據觀(guan)研天(tian)下(xia)的新(xin)研究(jiu),增(zeng)加(jia)(jia)有(you)機硅(gui)(gui)(gui)材(cai)料在汽(qi)(qi)車(che)零(ling)部件(jian)方面的用(yong)量(liang)(liang)(liang)(liang),可以大幅度提高(gao)汽(qi)(qi)車(che)的安全性能(neng),因此,汽(qi)(qi)車(che)產(chan)量(liang)(liang)(liang)(liang)和(he)單車(che)用(yong)量(liang)(liang)(liang)(liang)水平的提高(gao)都(dou)將(jiang)推動汽(qi)(qi)車(che)工(gong)業(ye)對硅(gui)(gui)(gui)橡膠(jiao)(jiao)需求的增(zeng)加(jia)(jia)。國(guo)家鼓勵自主品(pin)牌(pai)的汽(qi)(qi)車(che)發(fa)展,關鍵汽(qi)(qi)車(che)零(ling)部件(jian)實現(xian)自主化,《2012年(nian)(nian)度黨政機關公務用(yong)車(che)選用(yong)車(che)型目(mu)(mu)錄(lu)(征求意見稿)》為自主品(pin)牌(pai)擴(kuo)大在政府采購的市場份額,為改變目(mu)(mu)前(qian)國(guo)內政府采購以合資品(pin)牌(pai)產(chan)品(pin)為主的局(ju)面提供(gong)了保障。促進自主品(pin)牌(pai)發(fa)展,國(guo)產(chan)汽(qi)(qi)車(che)業(ye)的繁榮將(jiang)為汽(qi)(qi)車(che)膠(jiao)(jiao)的應用(yong)提供(gong)有(you)力保障。預測未來3年(nian)(nian),我國(guo)室溫硫化硅(gui)(gui)(gui)橡膠(jiao)(jiao)在汽(qi)(qi)車(che)行(xing)業(ye)將(jiang)以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)橡膠(jiao)(jiao)是(shi)重要的(de)非石油基合(he)成(cheng)橡膠(jiao)(jiao),約(yue)占非石油基合(he)成(cheng)橡膠(jiao)(jiao)消費量的(de)98%。但因(yin)為(wei)石油價格的(de)大(da)幅(fu)上(shang)漲,同(tong)時我(wo)國(guo)在(zai)硅(gui)橡膠(jiao)(jiao)的(de)關(guan)鍵原(yuan)(yuan)料有(you)(you)機硅(gui)單體的(de)生(sheng)產(chan)技(ji)術方(fang)面(mian)取(qu)得突破,有(you)(you)機硅(gui)單體的(de)生(sheng)產(chan)技(ji)術在(zai)2005年前被幾(ji)家跨國(guo)公司壟斷,但目前我(wo)國(guo)已發展成(cheng)為(wei)全球有(you)(you)機硅(gui)單體第1大(da)國(guo),這(zhe)2個方(fang)面(mian)原(yuan)(yuan)因(yin)使(shi)硅(gui)橡膠(jiao)(jiao)的(de)價格從2011年起開(kai)(kai)始(shi)低于石油基合(he)成(cheng)橡膠(jiao)(jiao),僅約(yue)為(wei)大(da)宗石油基橡膠(jiao)(jiao)的(de)80%~90%,成(cheng)為(wei)廉價的(de)合(he)成(cheng)橡膠(jiao)(jiao),并開(kai)(kai)始(shi)大(da)規模替代石油基合(he)成(cheng)橡膠(jiao)(jiao)。這(zhe)將極大(da)拓展有(you)(you)機硅(gui)產(chan)業的(de)市場(chang)空間,同(tong)時將帶動硅(gui)油、硅(gui)烷偶聯劑和硅(gui)樹(shu)脂等其(qi)他(ta)有(you)(you)機硅(gui)產(chan)品的(de)消費。