硅橡膠是指(zhi)主鏈由硅(gui)(gui)和氧(yang)原(yuan)(yuan)子(zi)交替構(gou)成(cheng),硅(gui)(gui)原(yuan)(yuan)子(zi)上通(tong)常連(lian)有兩個有機(ji)基(ji)團的(de)橡(xiang)(xiang)(xiang)膠(jiao)。普通(tong)的(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)主要由含甲基(ji)和少量乙(yi)烯基(ji)的(de)硅(gui)(gui)氧(yang)鏈節組成(cheng)。苯(ben)基(ji)的(de)引入可提高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)高(gao)(gao)、低(di)溫性(xing)能(neng),三氟丙基(ji)及(ji)氰(qing)基(ji)的(de)引入則可提高(gao)(gao)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)溫及(ji)耐(nai)油性(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)耐(nai)低(di)溫性(xing)能(neng)良好,一般在(zai)(zai)-55℃下仍能(neng)工(gong)作(zuo)。引入苯(ben)基(ji)后,可達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)耐(nai)熱(re)性(xing)能(neng)也很突出,在(zai)(zai)180℃下可長(chang)期工(gong)作(zuo),稍高(gao)(gao)于200℃也能(neng)承受數周(zhou)或更(geng)長(chang)時(shi)間仍有彈性(xing),瞬時(shi)可耐(nai)300℃以上的(de)高(gao)(gao)溫。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)透氣性(xing)好,氧(yang)氣透過率在(zai)(zai)合(he)成(cheng)聚合(he)物中(zhong)是較高(gao)(gao)的(de)。此外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)還具(ju)有生理(li)惰性(xing)、不會導(dao)致凝血的(de)突出特性(xing),因此在(zai)(zai)醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)分類(lei)的(de)方法很(hen)多,通(tong)常按(an)固化前的(de)形態(tai)分為(wei)(wei)固體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)和(he)液體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)硫(liu)化溫(wen)度分為(wei)(wei)室溫(wen)硫(liu)化硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao),高(gao)(gao)溫(wen)硫(liu)化硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)所用單體的(de)不同,可分為(wei)(wei)甲基乙烯基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao),甲基苯基乙烯基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)、氟(fu)硅(gui)(gui)(gui)(gui),腈(jing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)等;按(an)性(xing)能和(he)用途的(de)不同又(you)可分為(wei)(wei)通(tong)用型(xing)、超(chao)耐(nai)(nai)低溫(wen)型(xing)、超(chao)耐(nai)(nai)高(gao)(gao)溫(wen)型(xing)、高(gao)(gao)強力型(xing)、耐(nai)(nai)油型(xing)、醫用型(xing)等等。
發展史
硅橡(xiang)(xiang)膠早期(qi)是由美國(guo)(guo)以三氯化(hua)鐵為催化(hua)劑合成的(de)(de)。1945年(nian),硅橡(xiang)(xiang)膠產品問世(shi)。1948年(nian),采(cai)用(yong)(yong)高比表面積(ji)的(de)(de)氣(qi)相法白炭黑補強的(de)(de)硅橡(xiang)(xiang)膠研(yan)制成功,使硅橡(xiang)(xiang)膠的(de)(de)性能(neng)躍(yue)升(sheng)到實用(yong)(yong)階段,奠(dian)定(ding)了現(xian)代硅橡(xiang)(xiang)膠生產技術的(de)(de)基礎。從二(er)甲基二(er)氯硅烷合成開始(shi)生產硅橡(xiang)(xiang)膠的(de)(de)國(guo)(guo)家有美國(guo)(guo)。俄羅斯、德國(guo)(guo)、日(ri)本(ben)、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠的(de)(de)工業(ye)化(hua)研(yan)究始(shi)于1957年(nian),多家研(yan)究所和企業(ye)陸(lu)續開發出各種硅橡(xiang)(xiang)膠。到2003年(nian)底,中(zhong)國(guo)(guo)硅橡(xiang)(xiang)膠生產能(neng)力為135千噸(dun),其中(zhong)高溫膠100千噸(dun)。
高溫硫化硅橡膠
高溫硫化(hua)(hua)硅(gui)(gui)(gui)橡膠(jiao)是(shi)指聚(ju)硅(gui)(gui)(gui)氧烷變成(cheng)彈性(xing)(xing)體(ti)的過程是(shi)經過高溫(110-170℃)硫化(hua)(hua)成(cheng)型(xing)的。它主要(yao)以高分子量(liang)的聚(ju)甲(jia)基乙烯基硅(gui)(gui)(gui)氧烷為生膠(jiao),混(hun)入(ru)(ru)補強(qiang)(qiang)填料、硫化(hua)(hua)劑等,在加(jia)熱加(jia)壓(ya)下硫化(hua)(hua)成(cheng)彈性(xing)(xing)體(ti)。硅(gui)(gui)(gui)橡膠(jiao)的補強(qiang)(qiang)主要(yao)是(shi)各種(zhong)類型(xing)的白炭黑,可使硫化(hua)(hua)膠(jiao)的強(qiang)(qiang)度增加(jia)數十(shi)倍(bei)。有(you)時為了降低(di)成(cheng)本或改(gai)善(shan)膠(jiao)料性(xing)(xing)能及(ji)賦予硫化(hua)(hua)膠(jiao)各種(zhong)特(te)殊的性(xing)(xing)能,也加(jia)入(ru)(ru)相應的各種(zhong)添(tian)加(jia)劑。硫化(hua)(hua)劑是(shi)各種(zhong)有(you)機(ji)過氧化(hua)(hua)物或加(jia)成(cheng)反應催化(hua)(hua)劑。
加工成(cheng)型方(fang)法如圖所示。一(yi)次硫化(hua)的目(mu)的是(shi)進行(xing)高分子(zi)鏈的交聯(lian)反應(ying);二(er)次硫化(hua)的目(mu)的是(shi)進行(xing)補充交聯(lian)、驅(qu)除硫化(hua)劑分解(jie)產物和(he)其他揮發(fa)性(xing)(xing)化(hua)合物以(yi)穩定硫化(hua)膠的各項性(xing)(xing)能。常用的設備有開放式煉(lian)膠機(ji)、捏(nie)合機(ji)及真空密(mi)煉(lian)機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)(xian)著的(de)(de)特(te)(te)征(zheng)是(shi)高溫(wen)(wen)(wen)(wen)穩定(ding)(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)強(qiang)度僅是(shi)天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某(mou)些合成(cheng)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)一(yi)半,但在200℃以上的(de)(de)高溫(wen)(wen)(wen)(wen)環境下(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持一(yi)定(ding)(ding)(ding)的(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面(mian)硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無(wu)明(ming)顯(xian)(xian)變化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)玻(bo)璃(li)化溫(wen)(wen)(wen)(wen)度一(yi)般為-70~-50℃,特(te)(te)殊(shu)配方可達-100℃,表明(ming)其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異。這對(dui)航(hang)(hang)空(kong)、宇航(hang)(hang)工業(ye)的(de)(de)意義(yi)重(zhong)大。(3)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及(ji)紫外線等十分穩定(ding)(ding)(ding),在不加(jia)任何添加(jia)劑(ji)(ji)的(de)(de)情況下(xia)(xia),就具(ju)有(you)優(you)良的(de)(de)耐(nai)(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)優(you)異的(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)(xia)的(de)(de)物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通(tong)用橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)高溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)低溫(wen)(wen)(wen)(wen)下(xia)(xia),其物(wu)理機械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通(tong)用橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)(nai)油及(ji)化學試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)中等的(de)(de)耐(nai)(nai)(nai)油、耐(nai)(nai)(nai)溶(rong)劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空(kong)氣(qi)、氮(dan)、氧(yang)、二(er)氧(yang)化碳等氣(qi)體的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味(wei),無(wu)嗅,與人體組織(zhi)不粘連,具(ju)有(you)抗(kang)凝血作用,對(dui)肌體組織(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)(te)別(bie)適合作為醫用材料。
硅橡膠的用量
據(ju)中(zhong)國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)(che)(che)工業協會統計,2012年(nian),汽(qi)(qi)(qi)車(che)(che)(che)(che)產銷分別(bie)達到(dao)1927.18萬輛(liang)(liang)和(he)1930.64萬輛(liang)(liang),同比分別(bie)增(zeng)(zeng)長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)(che)(che)工業硅(gui)橡(xiang)膠(jiao)的用(yong)(yong)(yong)量(liang)(liang)約(yue)達2.0萬t。根據(ju)觀(guan)研天下(xia)的新研究,增(zeng)(zeng)加有機硅(gui)材料在(zai)汽(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部件方面(mian)的用(yong)(yong)(yong)量(liang)(liang),可以(yi)大(da)幅度(du)(du)提(ti)高(gao)汽(qi)(qi)(qi)車(che)(che)(che)(che)的安(an)全性能,因(yin)此,汽(qi)(qi)(qi)車(che)(che)(che)(che)產量(liang)(liang)和(he)單車(che)(che)(che)(che)用(yong)(yong)(yong)量(liang)(liang)水平的提(ti)高(gao)都將(jiang)(jiang)推(tui)動汽(qi)(qi)(qi)車(che)(che)(che)(che)工業對(dui)硅(gui)橡(xiang)膠(jiao)需求的增(zeng)(zeng)加。國(guo)(guo)家鼓勵自(zi)(zi)(zi)主(zhu)(zhu)品(pin)牌(pai)的汽(qi)(qi)(qi)車(che)(che)(che)(che)發(fa)展(zhan),關鍵(jian)汽(qi)(qi)(qi)車(che)(che)(che)(che)零(ling)部件實現自(zi)(zi)(zi)主(zhu)(zhu)化,《2012年(nian)度(du)(du)黨(dang)政機關公務用(yong)(yong)(yong)車(che)(che)(che)(che)選用(yong)(yong)(yong)車(che)(che)(che)(che)型目錄(征求意見稿)》為(wei)自(zi)(zi)(zi)主(zhu)(zhu)品(pin)牌(pai)擴(kuo)大(da)在(zai)政府采購(gou)的市場份額,為(wei)改變目前國(guo)(guo)內政府采購(gou)以(yi)合資品(pin)牌(pai)產品(pin)為(wei)主(zhu)(zhu)的局面(mian)提(ti)供(gong)了保障。促進(jin)自(zi)(zi)(zi)主(zhu)(zhu)品(pin)牌(pai)發(fa)展(zhan),國(guo)(guo)產汽(qi)(qi)(qi)車(che)(che)(che)(che)業的繁榮(rong)將(jiang)(jiang)為(wei)汽(qi)(qi)(qi)車(che)(che)(che)(che)膠(jiao)的應(ying)用(yong)(yong)(yong)提(ti)供(gong)有力保障。預測未來3年(nian),我國(guo)(guo)室溫硫(liu)化硅(gui)橡(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)車(che)(che)(che)(che)行業將(jiang)(jiang)以(yi)年(nian)均(jun)20%增(zeng)(zeng)長。
此(ci)外(wai),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重要(yao)的(de)(de)(de)非石(shi)(shi)油(you)(you)(you)(you)基(ji)合(he)成橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)(you)(you)(you)基(ji)合(he)成橡(xiang)膠(jiao)(jiao)(jiao)消(xiao)費量的(de)(de)(de)98%。但因為(wei)石(shi)(shi)油(you)(you)(you)(you)價(jia)格的(de)(de)(de)大(da)(da)幅(fu)上漲(zhang),同時我國(guo)在(zai)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關鍵原料(liao)有(you)機硅(gui)(gui)單體的(de)(de)(de)生(sheng)產(chan)技(ji)術方(fang)面取得突(tu)破(po),有(you)機硅(gui)(gui)單體的(de)(de)(de)生(sheng)產(chan)技(ji)術在(zai)2005年(nian)前(qian)(qian)被幾家跨國(guo)公(gong)司壟斷,但目前(qian)(qian)我國(guo)已發展成為(wei)全球(qiu)有(you)機硅(gui)(gui)單體第1大(da)(da)國(guo),這2個方(fang)面原因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價(jia)格從2011年(nian)起開始(shi)低(di)于石(shi)(shi)油(you)(you)(you)(you)基(ji)合(he)成橡(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大(da)(da)宗石(shi)(shi)油(you)(you)(you)(you)基(ji)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成為(wei)廉價(jia)的(de)(de)(de)合(he)成橡(xiang)膠(jiao)(jiao)(jiao),并開始(shi)大(da)(da)規模替代石(shi)(shi)油(you)(you)(you)(you)基(ji)合(he)成橡(xiang)膠(jiao)(jiao)(jiao)。這將(jiang)極大(da)(da)拓(tuo)展有(you)機硅(gui)(gui)產(chan)業的(de)(de)(de)市場(chang)空(kong)間,同時將(jiang)帶動硅(gui)(gui)油(you)(you)(you)(you)、硅(gui)(gui)烷偶(ou)聯劑和(he)硅(gui)(gui)樹脂等其他有(you)機硅(gui)(gui)產(chan)品的(de)(de)(de)消(xiao)費。