
硅橡膠是(shi)指主鏈由硅和(he)氧原子(zi)(zi)交替構(gou)成(cheng),硅原子(zi)(zi)上通常連有(you)(you)(you)兩個有(you)(you)(you)機(ji)基(ji)(ji)團的(de)(de)(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)(de)(de)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主要由含甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)(de)(de)硅氧鏈節(jie)組(zu)成(cheng)。苯基(ji)(ji)的(de)(de)(de)引入(ru)(ru)可(ke)提(ti)高(gao)(gao)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐(nai)高(gao)(gao)、低溫性(xing)(xing)能(neng)(neng),三氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)(de)引入(ru)(ru)則可(ke)提(ti)高(gao)(gao)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐(nai)溫及耐(nai)油性(xing)(xing)能(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐(nai)低溫性(xing)(xing)能(neng)(neng)良好,一般在(zai)-55℃下仍(reng)能(neng)(neng)工(gong)作。引入(ru)(ru)苯基(ji)(ji)后(hou),可(ke)達-73℃。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)耐(nai)熱性(xing)(xing)能(neng)(neng)也(ye)很突出,在(zai)180℃下可(ke)長(chang)期工(gong)作,稍高(gao)(gao)于200℃也(ye)能(neng)(neng)承受數周(zhou)或更長(chang)時間仍(reng)有(you)(you)(you)彈性(xing)(xing),瞬時可(ke)耐(nai)300℃以上的(de)(de)(de)高(gao)(gao)溫。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)透氣性(xing)(xing)好,氧氣透過(guo)率在(zai)合成(cheng)聚合物中(zhong)是(shi)較高(gao)(gao)的(de)(de)(de)。此外,硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有(you)(you)(you)生理惰性(xing)(xing)、不會導致凝血的(de)(de)(de)突出特性(xing)(xing),因此在(zai)醫用(yong)領域應(ying)用(yong)廣泛。
主要品種
硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)分類的方法很(hen)多(duo),通常按(an)固化(hua)(hua)前的形態分為(wei)固體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)和液(ye)體硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)硫(liu)化(hua)(hua)溫度(du)分為(wei)室溫硫(liu)化(hua)(hua)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),高溫硫(liu)化(hua)(hua)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)所用單體的不(bu)同,可分為(wei)甲基乙烯基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲基苯(ben)基乙烯基硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟(fu)硅(gui)(gui)(gui)(gui),腈硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)等(deng)(deng);按(an)性能(neng)和用途的不(bu)同又可分為(wei)通用型(xing)(xing)、超耐(nai)低溫型(xing)(xing)、超耐(nai)高溫型(xing)(xing)、高強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用型(xing)(xing)等(deng)(deng)等(deng)(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期(qi)是由美國(guo)(guo)以三氯(lv)化(hua)鐵為(wei)催化(hua)劑合成(cheng)的。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產品問世。1948年(nian),采用(yong)高(gao)(gao)比表(biao)面積的氣相法白炭黑補強的硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研(yan)制成(cheng)功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性能躍升到實用(yong)階段,奠定了現代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產技術(shu)的基礎。從(cong)二甲基二氯(lv)硅(gui)(gui)烷合成(cheng)開始(shi)生產硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國(guo)(guo)家有美國(guo)(guo)。俄羅斯、德國(guo)(guo)、日本、韓國(guo)(guo)和中國(guo)(guo)等。中國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業(ye)化(hua)研(yan)究始(shi)于1957年(nian),多家研(yan)究所和企業(ye)陸續(xu)開發出(chu)各種(zhong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到2003年(nian)底,中國(guo)(guo)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生產能力(li)為(wei)135千(qian)噸,其中高(gao)(gao)溫膠(jiao)100千(qian)噸。
高溫硫化硅橡膠
高溫硫化(hua)(hua)硅(gui)橡膠(jiao)(jiao)是(shi)指聚(ju)硅(gui)氧(yang)(yang)烷變(bian)成(cheng)彈(dan)性(xing)體的過程是(shi)經過高溫(110-170℃)硫化(hua)(hua)成(cheng)型(xing)的。它(ta)主(zhu)要以高分子(zi)量的聚(ju)甲基乙烯基硅(gui)氧(yang)(yang)烷為生膠(jiao)(jiao),混(hun)入(ru)補強填料、硫化(hua)(hua)劑等,在加(jia)(jia)熱加(jia)(jia)壓(ya)下硫化(hua)(hua)成(cheng)彈(dan)性(xing)體。硅(gui)橡膠(jiao)(jiao)的補強主(zhu)要是(shi)各種類型(xing)的白(bai)炭黑,可使硫化(hua)(hua)膠(jiao)(jiao)的強度增加(jia)(jia)數十倍。有時為了(le)降低(di)成(cheng)本(ben)或(huo)改善(shan)膠(jiao)(jiao)料性(xing)能及賦予(yu)硫化(hua)(hua)膠(jiao)(jiao)各種特殊(shu)的性(xing)能,也加(jia)(jia)入(ru)相(xiang)應的各種添加(jia)(jia)劑。硫化(hua)(hua)劑是(shi)各種有機(ji)過氧(yang)(yang)化(hua)(hua)物或(huo)加(jia)(jia)成(cheng)反應催(cui)化(hua)(hua)劑。
加工成型方法(fa)如圖(tu)所示(shi)。一次(ci)硫化(hua)的目的是進行高分子鏈的交聯反應;二次(ci)硫化(hua)的目的是進行補(bu)充交聯、驅(qu)除硫化(hua)劑分解產物和其他(ta)揮發性化(hua)合(he)物以穩定硫化(hua)膠(jiao)的各項(xiang)性能。常(chang)用(yong)的設(she)備(bei)有(you)開放式(shi)煉膠(jiao)機、捏合(he)機及真空密煉機。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)特征(zheng)是(shi)高溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)強度僅是(shi)天(tian)(tian)然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)一半,但在(zai)200℃以上(shang)的(de)(de)(de)高溫(wen)(wen)(wen)(wen)環(huan)境下(xia)(xia)(xia)(xia),硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)保持一定的(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)無明(ming)顯變化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)(wen)度一般為(wei)(wei)-70~-50℃,特殊配方可達-100℃,表明(ming)其低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)異。這對(dui)航(hang)空、宇航(hang)工(gong)業的(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫(zi)外(wai)線等(deng)十分(fen)穩(wen)定,在(zai)不加(jia)任何添(tian)加(jia)劑(ji)的(de)(de)(de)情況下(xia)(xia)(xia)(xia),就(jiu)具(ju)(ju)有(you)優(you)良的(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)優(you)異的(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)(chang)好。(5)物理(li)(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)常(chang)(chang)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)(xia)的(de)(de)(de)物理(li)(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)比通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)差(cha),但在(zai)150℃的(de)(de)(de)高溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)低溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)(xia),其物理(li)(li)(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)優(you)于(yu)通用橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油及化學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)具(ju)(ju)有(you)中等(deng)的(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)(xia)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化碳等(deng)氣(qi)體的(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天(tian)(tian)然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)高出30-50倍。(8)生(sheng)理(li)(li)(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅(xiu),與人體組織(zhi)(zhi)不粘連,具(ju)(ju)有(you)抗凝血作(zuo)用,對(dui)肌(ji)體組織(zhi)(zhi)的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)(chang)少(shao)。特別適(shi)合作(zuo)為(wei)(wei)醫用材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)車(che)(che)(che)產(chan)(chan)銷分(fen)別達到1927.18萬(wan)輛和1930.64萬(wan)輛,同比(bi)分(fen)別增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)硅橡(xiang)膠的用(yong)量(liang)約達2.0萬(wan)t。根據觀研(yan)天下的新(xin)研(yan)究,增(zeng)加(jia)有(you)機硅材(cai)料在汽(qi)(qi)車(che)(che)(che)零(ling)部件(jian)方(fang)面的用(yong)量(liang),可以大(da)幅度提(ti)高汽(qi)(qi)車(che)(che)(che)的安全性(xing)能,因此(ci),汽(qi)(qi)車(che)(che)(che)產(chan)(chan)量(liang)和單車(che)(che)(che)用(yong)量(liang)水平的提(ti)高都將(jiang)推動汽(qi)(qi)車(che)(che)(che)工(gong)業(ye)(ye)(ye)對硅橡(xiang)膠需求的增(zeng)加(jia)。國(guo)家鼓勵自(zi)(zi)主品(pin)(pin)牌(pai)的汽(qi)(qi)車(che)(che)(che)發展(zhan)(zhan),關鍵(jian)汽(qi)(qi)車(che)(che)(che)零(ling)部件(jian)實現自(zi)(zi)主化(hua)(hua),《2012年(nian)(nian)度黨(dang)政(zheng)機關公(gong)務用(yong)車(che)(che)(che)選用(yong)車(che)(che)(che)型目錄(征求意(yi)見稿)》為(wei)自(zi)(zi)主品(pin)(pin)牌(pai)擴(kuo)大(da)在政(zheng)府(fu)(fu)采(cai)購(gou)的市場份(fen)額,為(wei)改變目前(qian)國(guo)內政(zheng)府(fu)(fu)采(cai)購(gou)以合資品(pin)(pin)牌(pai)產(chan)(chan)品(pin)(pin)為(wei)主的局(ju)面提(ti)供(gong)(gong)了(le)保障(zhang)。促進自(zi)(zi)主品(pin)(pin)牌(pai)發展(zhan)(zhan),國(guo)產(chan)(chan)汽(qi)(qi)車(che)(che)(che)業(ye)(ye)(ye)的繁榮將(jiang)為(wei)汽(qi)(qi)車(che)(che)(che)膠的應用(yong)提(ti)供(gong)(gong)有(you)力保障(zhang)。預測(ce)未來(lai)3年(nian)(nian),我國(guo)室溫(wen)硫(liu)化(hua)(hua)硅橡(xiang)膠在汽(qi)(qi)車(che)(che)(che)行業(ye)(ye)(ye)將(jiang)以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要的(de)非石油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),約(yue)占非石油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)消費量的(de)98%。但因(yin)為(wei)(wei)石油(you)(you)價(jia)格(ge)的(de)大幅(fu)上漲,同時(shi)我國在(zai)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)關鍵原(yuan)料有機硅(gui)(gui)單體(ti)(ti)(ti)的(de)生(sheng)產(chan)(chan)技術方面取得(de)突破,有機硅(gui)(gui)單體(ti)(ti)(ti)的(de)生(sheng)產(chan)(chan)技術在(zai)2005年(nian)前被幾家跨國公(gong)司(si)壟斷(duan),但目(mu)前我國已發展成(cheng)(cheng)為(wei)(wei)全球有機硅(gui)(gui)單體(ti)(ti)(ti)第1大國,這(zhe)2個方面原(yuan)因(yin)使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)價(jia)格(ge)從(cong)2011年(nian)起(qi)開(kai)始低于(yu)石油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),僅約(yue)為(wei)(wei)大宗石油(you)(you)基(ji)橡(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為(wei)(wei)廉(lian)價(jia)的(de)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao),并開(kai)始大規模替代石油(you)(you)基(ji)合成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)。這(zhe)將極大拓展有機硅(gui)(gui)產(chan)(chan)業的(de)市場(chang)空間,同時(shi)將帶動(dong)硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)樹脂等其他(ta)有機硅(gui)(gui)產(chan)(chan)品的(de)消費。