硅橡膠是(shi)指主鏈由硅(gui)(gui)和(he)氧原子交替(ti)構成(cheng),硅(gui)(gui)原子上(shang)通常(chang)連有(you)兩個(ge)有(you)機基(ji)團的(de)(de)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)。普通的(de)(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)主要由含甲(jia)基(ji)和(he)少量乙烯基(ji)的(de)(de)硅(gui)(gui)氧鏈節(jie)組成(cheng)。苯(ben)基(ji)的(de)(de)引入(ru)(ru)可(ke)(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐高、低溫(wen)性(xing)能(neng)(neng),三氟丙基(ji)及氰基(ji)的(de)(de)引入(ru)(ru)則可(ke)(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐溫(wen)及耐油性(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)耐低溫(wen)性(xing)能(neng)(neng)良好,一般在(zai)-55℃下仍能(neng)(neng)工(gong)作(zuo)。引入(ru)(ru)苯(ben)基(ji)后,可(ke)(ke)(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)耐熱(re)性(xing)能(neng)(neng)也(ye)很突(tu)出,在(zai)180℃下可(ke)(ke)(ke)長期工(gong)作(zuo),稍高于200℃也(ye)能(neng)(neng)承受數周或更長時間仍有(you)彈性(xing),瞬時可(ke)(ke)(ke)耐300℃以上(shang)的(de)(de)高溫(wen)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)透氣(qi)性(xing)好,氧氣(qi)透過率在(zai)合成(cheng)聚合物中(zhong)是(shi)較高的(de)(de)。此(ci)(ci)外,硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)還具有(you)生理(li)惰性(xing)、不會(hui)導致凝血(xue)的(de)(de)突(tu)出特性(xing),因此(ci)(ci)在(zai)醫用領域應(ying)用廣泛。
主要品種
硅(gui)橡(xiang)膠分類的(de)(de)方法很多,通常按固(gu)化(hua)前的(de)(de)形態分為固(gu)體硅(gui)橡(xiang)膠和液體硅(gui)橡(xiang)膠;按硫化(hua)溫(wen)度分為室溫(wen)硫化(hua)硅(gui)橡(xiang)膠,高溫(wen)硫化(hua)硅(gui)橡(xiang)膠;按所用(yong)(yong)單體的(de)(de)不同,可(ke)分為甲基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)膠,甲基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)膠、氟硅(gui),腈硅(gui)橡(xiang)膠等;按性能和用(yong)(yong)途的(de)(de)不同又(you)可(ke)分為通用(yong)(yong)型(xing)(xing)(xing)、超耐(nai)低溫(wen)型(xing)(xing)(xing)、超耐(nai)高溫(wen)型(xing)(xing)(xing)、高強力型(xing)(xing)(xing)、耐(nai)油(you)型(xing)(xing)(xing)、醫用(yong)(yong)型(xing)(xing)(xing)等等。
發展史
硅(gui)(gui)(gui)橡(xiang)膠(jiao)早期(qi)是由美國(guo)(guo)(guo)以(yi)三氯(lv)化鐵為催化劑合成的(de)(de)(de)。1945年,硅(gui)(gui)(gui)橡(xiang)膠(jiao)產(chan)品問世。1948年,采(cai)用(yong)高(gao)比表面積的(de)(de)(de)氣相法白炭黑補強的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠(jiao)研制成功,使硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)性能躍升到實(shi)用(yong)階段,奠定了現代(dai)硅(gui)(gui)(gui)橡(xiang)膠(jiao)生產(chan)技術的(de)(de)(de)基礎。從二甲基二氯(lv)硅(gui)(gui)(gui)烷合成開始(shi)生產(chan)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)國(guo)(guo)(guo)家有美國(guo)(guo)(guo)。俄羅斯、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)國(guo)(guo)(guo)等。中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)的(de)(de)(de)工業(ye)化研究始(shi)于1957年,多家研究所和企業(ye)陸續開發(fa)出各種硅(gui)(gui)(gui)橡(xiang)膠(jiao)。到2003年底,中(zhong)國(guo)(guo)(guo)硅(gui)(gui)(gui)橡(xiang)膠(jiao)生產(chan)能力為135千噸,其中(zhong)高(gao)溫膠(jiao)100千噸。
高溫硫化硅橡膠
高溫硫化(hua)(hua)(hua)硅(gui)橡(xiang)膠(jiao)是(shi)指聚(ju)硅(gui)氧(yang)烷變成彈性體的(de)(de)(de)過程是(shi)經過高溫(110-170℃)硫化(hua)(hua)(hua)成型的(de)(de)(de)。它主(zhu)要(yao)以高分子(zi)量的(de)(de)(de)聚(ju)甲基乙烯基硅(gui)氧(yang)烷為(wei)生膠(jiao),混入補(bu)強(qiang)填(tian)料(liao)、硫化(hua)(hua)(hua)劑(ji)等,在加熱(re)加壓下硫化(hua)(hua)(hua)成彈性體。硅(gui)橡(xiang)膠(jiao)的(de)(de)(de)補(bu)強(qiang)主(zhu)要(yao)是(shi)各種(zhong)類(lei)型的(de)(de)(de)白炭黑,可使硫化(hua)(hua)(hua)膠(jiao)的(de)(de)(de)強(qiang)度增加數(shu)十(shi)倍。有時為(wei)了降低成本或(huo)改(gai)善膠(jiao)料(liao)性能及(ji)賦予硫化(hua)(hua)(hua)膠(jiao)各種(zhong)特殊的(de)(de)(de)性能,也加入相應(ying)的(de)(de)(de)各種(zhong)添(tian)加劑(ji)。硫化(hua)(hua)(hua)劑(ji)是(shi)各種(zhong)有機過氧(yang)化(hua)(hua)(hua)物或(huo)加成反應(ying)催(cui)化(hua)(hua)(hua)劑(ji)。
加工成型(xing)方法如圖(tu)所示。一次硫(liu)化(hua)的(de)目的(de)是進(jin)行高分(fen)子鏈的(de)交聯(lian)反應(ying);二次硫(liu)化(hua)的(de)目的(de)是進(jin)行補充交聯(lian)、驅除(chu)硫(liu)化(hua)劑分(fen)解(jie)產(chan)物(wu)和(he)其(qi)他(ta)揮(hui)發性(xing)化(hua)合(he)物(wu)以穩(wen)定硫(liu)化(hua)膠的(de)各(ge)項性(xing)能。常用(yong)的(de)設(she)備有(you)開放式(shi)煉(lian)膠機(ji)(ji)、捏合(he)機(ji)(ji)及真空密煉(lian)機(ji)(ji)。
主要性能
(1)高溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的特征是高溫(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常(chang)溫(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的強度僅是天(tian)然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的一半,但(dan)在(zai)200℃以上的高溫(wen)(wen)環境下(xia),硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持(chi)一定(ding)的柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明(ming)顯變化(hua)(hua)。(2)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的玻璃化(hua)(hua)溫(wen)(wen)度一般為-70~-50℃,特殊配方可達-100℃,表明(ming)其(qi)低(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優異。這對(dui)航空、宇航工業的意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)(yang)、臭(chou)氧(yang)(yang)及(ji)紫外線等(deng)十分(fen)穩定(ding),在(zai)不加任何添加劑的情況下(xia),就具(ju)(ju)有(you)(you)優良(liang)的耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)優異的絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好(hao)。(5)物理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)下(xia)的物理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但(dan)在(zai)150℃的高溫(wen)(wen)和-50℃的低(di)溫(wen)(wen)下(xia),其(qi)物理(li)機(ji)械(xie)(xie)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優于(yu)通用(yong)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化(hua)(hua)學試劑性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)(you)中等(deng)的耐(nai)油、耐(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)下(xia)硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)(qi)(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化(hua)(hua)碳等(deng)氣(qi)(qi)(qi)體(ti)(ti)的透氣(qi)(qi)(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍(bei)。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒(du),無(wu)味(wei),無(wu)嗅,與(yu)人體(ti)(ti)組織(zhi)不粘連,具(ju)(ju)有(you)(you)抗凝血作(zuo)用(yong),對(dui)肌體(ti)(ti)組織(zhi)的反應性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別適(shi)合作(zuo)為醫(yi)用(yong)材料(liao)。
硅橡膠的用量
據(ju)中(zhong)國(guo)汽(qi)(qi)車(che)(che)工(gong)(gong)業協(xie)會統計,2012年,汽(qi)(qi)車(che)(che)產(chan)銷分(fen)(fen)別達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比分(fen)(fen)別增(zeng)(zeng)(zeng)長(chang)4.63%和4.33%,汽(qi)(qi)車(che)(che)工(gong)(gong)業硅(gui)橡膠的(de)(de)用(yong)量約達2.0萬(wan)t。根據(ju)觀(guan)研(yan)天下的(de)(de)新研(yan)究(jiu),增(zeng)(zeng)(zeng)加(jia)有(you)(you)機硅(gui)材(cai)料在汽(qi)(qi)車(che)(che)零(ling)部(bu)件方面(mian)的(de)(de)用(yong)量,可(ke)以大(da)(da)幅度提(ti)(ti)高(gao)汽(qi)(qi)車(che)(che)的(de)(de)安全性(xing)能,因此,汽(qi)(qi)車(che)(che)產(chan)量和單車(che)(che)用(yong)量水平的(de)(de)提(ti)(ti)高(gao)都將推(tui)動汽(qi)(qi)車(che)(che)工(gong)(gong)業對硅(gui)橡膠需求的(de)(de)增(zeng)(zeng)(zeng)加(jia)。國(guo)家鼓勵自主(zhu)品牌(pai)的(de)(de)汽(qi)(qi)車(che)(che)發展(zhan),關鍵汽(qi)(qi)車(che)(che)零(ling)部(bu)件實(shi)現自主(zhu)化(hua),《2012年度黨政機關公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(lu)(征求意見稿)》為(wei)自主(zhu)品牌(pai)擴(kuo)大(da)(da)在政府(fu)采購的(de)(de)市場份額,為(wei)改變(bian)目前國(guo)內(nei)政府(fu)采購以合資品牌(pai)產(chan)品為(wei)主(zhu)的(de)(de)局(ju)面(mian)提(ti)(ti)供(gong)了保(bao)障。促進自主(zhu)品牌(pai)發展(zhan),國(guo)產(chan)汽(qi)(qi)車(che)(che)業的(de)(de)繁榮將為(wei)汽(qi)(qi)車(che)(che)膠的(de)(de)應用(yong)提(ti)(ti)供(gong)有(you)(you)力保(bao)障。預測未來3年,我國(guo)室溫硫化(hua)硅(gui)橡膠在汽(qi)(qi)車(che)(che)行業將以年均(jun)20%增(zeng)(zeng)(zeng)長(chang)。
此外,硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)是重(zhong)要(yao)的(de)非(fei)石(shi)(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),約占非(fei)石(shi)(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)消(xiao)費(fei)量的(de)98%。但因為(wei)(wei)(wei)石(shi)(shi)油(you)(you)價格(ge)的(de)大(da)幅上漲,同時我國(guo)在硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)關鍵原料有機(ji)硅(gui)(gui)單(dan)體的(de)生(sheng)產技術(shu)方(fang)面取得突破(po),有機(ji)硅(gui)(gui)單(dan)體的(de)生(sheng)產技術(shu)在2005年前被(bei)幾家跨(kua)國(guo)公司(si)壟(long)斷,但目前我國(guo)已發展(zhan)(zhan)成(cheng)為(wei)(wei)(wei)全(quan)球有機(ji)硅(gui)(gui)單(dan)體第(di)1大(da)國(guo),這2個方(fang)面原因使(shi)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)價格(ge)從2011年起(qi)開始低(di)于石(shi)(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),僅約為(wei)(wei)(wei)大(da)宗石(shi)(shi)油(you)(you)基(ji)(ji)橡(xiang)(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)為(wei)(wei)(wei)廉價的(de)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao),并開始大(da)規模替代(dai)石(shi)(shi)油(you)(you)基(ji)(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)拓(tuo)展(zhan)(zhan)有機(ji)硅(gui)(gui)產業的(de)市(shi)場空間,同時將(jiang)帶(dai)動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂等其他有機(ji)硅(gui)(gui)產品(pin)的(de)消(xiao)費(fei)。