
硅橡膠是(shi)指主鏈(lian)由(you)硅(gui)(gui)(gui)(gui)和氧(yang)原子(zi)交替構成(cheng),硅(gui)(gui)(gui)(gui)原子(zi)上(shang)通常(chang)連有兩個有機(ji)基(ji)團的(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。普通的(de)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)主要由(you)含甲(jia)基(ji)和少(shao)量乙(yi)烯基(ji)的(de)硅(gui)(gui)(gui)(gui)氧(yang)鏈(lian)節(jie)組成(cheng)。苯基(ji)的(de)引入可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)耐(nai)高(gao)、低溫(wen)性(xing)能(neng),三氟(fu)丙基(ji)及(ji)氰基(ji)的(de)引入則可提高(gao)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)耐(nai)溫(wen)及(ji)耐(nai)油性(xing)能(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)耐(nai)低溫(wen)性(xing)能(neng)良好,一般在(zai)-55℃下仍能(neng)工(gong)(gong)作。引入苯基(ji)后,可達(da)-73℃。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)耐(nai)熱性(xing)能(neng)也很突出(chu),在(zai)180℃下可長期工(gong)(gong)作,稍高(gao)于200℃也能(neng)承受數周或更長時間仍有彈性(xing),瞬時可耐(nai)300℃以上(shang)的(de)高(gao)溫(wen)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)透氣(qi)性(xing)好,氧(yang)氣(qi)透過率在(zai)合(he)成(cheng)聚(ju)合(he)物(wu)中是(shi)較高(gao)的(de)。此(ci)外,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)還(huan)具有生(sheng)理惰性(xing)、不會導致(zhi)凝(ning)血的(de)突出(chu)特(te)性(xing),因此(ci)在(zai)醫用領域應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)分(fen)類(lei)的(de)(de)方法很(hen)多(duo),通常按(an)固(gu)化(hua)(hua)前的(de)(de)形態分(fen)為(wei)(wei)(wei)固(gu)體(ti)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)和液體(ti)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)硫(liu)化(hua)(hua)溫(wen)度分(fen)為(wei)(wei)(wei)室(shi)溫(wen)硫(liu)化(hua)(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),高溫(wen)硫(liu)化(hua)(hua)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao);按(an)所用單體(ti)的(de)(de)不同,可分(fen)為(wei)(wei)(wei)甲基(ji)(ji)(ji)(ji)乙烯基(ji)(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),甲基(ji)(ji)(ji)(ji)苯(ben)基(ji)(ji)(ji)(ji)乙烯基(ji)(ji)(ji)(ji)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)等(deng);按(an)性能和用途的(de)(de)不同又可分(fen)為(wei)(wei)(wei)通用型(xing)(xing)(xing)、超耐低(di)溫(wen)型(xing)(xing)(xing)、超耐高溫(wen)型(xing)(xing)(xing)、高強力型(xing)(xing)(xing)、耐油型(xing)(xing)(xing)、醫用型(xing)(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)早期是由(you)美國以三氯化鐵為催化劑合成(cheng)(cheng)的。1945年,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)產(chan)品問(wen)世。1948年,采用高比(bi)表面積(ji)的氣相法白炭黑補強的硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)研(yan)(yan)制(zhi)成(cheng)(cheng)功,使硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的性能躍(yue)升到(dao)實(shi)用階段,奠定了現(xian)代硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)技術的基礎。從二(er)甲基二(er)氯硅(gui)(gui)烷合成(cheng)(cheng)開始生(sheng)產(chan)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的國家有美國。俄羅斯、德國、日(ri)本、韓國和(he)中(zhong)國等(deng)。中(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的工業化研(yan)(yan)究始于1957年,多(duo)家研(yan)(yan)究所和(he)企業陸續開發出各種(zhong)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)。到(dao)2003年底,中(zhong)國硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)生(sheng)產(chan)能力為135千噸,其中(zhong)高溫膠(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)化(hua)(hua)(hua)硅橡(xiang)膠(jiao)是指聚(ju)硅氧烷變成(cheng)(cheng)彈性(xing)體的(de)(de)(de)過程是經(jing)過高溫(110-170℃)硫(liu)化(hua)(hua)(hua)成(cheng)(cheng)型的(de)(de)(de)。它主(zhu)要(yao)以(yi)高分子量的(de)(de)(de)聚(ju)甲基(ji)乙烯基(ji)硅氧烷為(wei)生膠(jiao),混入補(bu)強(qiang)填料(liao)、硫(liu)化(hua)(hua)(hua)劑等,在加熱加壓下(xia)硫(liu)化(hua)(hua)(hua)成(cheng)(cheng)彈性(xing)體。硅橡(xiang)膠(jiao)的(de)(de)(de)補(bu)強(qiang)主(zhu)要(yao)是各(ge)(ge)種類型的(de)(de)(de)白炭黑,可使硫(liu)化(hua)(hua)(hua)膠(jiao)的(de)(de)(de)強(qiang)度增加數(shu)十倍(bei)。有時為(wei)了降低成(cheng)(cheng)本(ben)或改善膠(jiao)料(liao)性(xing)能(neng)及賦予硫(liu)化(hua)(hua)(hua)膠(jiao)各(ge)(ge)種特(te)殊的(de)(de)(de)性(xing)能(neng),也加入相(xiang)應(ying)的(de)(de)(de)各(ge)(ge)種添加劑。硫(liu)化(hua)(hua)(hua)劑是各(ge)(ge)種有機過氧化(hua)(hua)(hua)物或加成(cheng)(cheng)反應(ying)催(cui)化(hua)(hua)(hua)劑。
加工成型方法如圖所示。一次(ci)硫(liu)(liu)化(hua)的(de)目的(de)是進(jin)行(xing)高(gao)分子鏈的(de)交聯(lian)反應;二次(ci)硫(liu)(liu)化(hua)的(de)目的(de)是進(jin)行(xing)補充交聯(lian)、驅除硫(liu)(liu)化(hua)劑(ji)分解產物(wu)和其他揮發性化(hua)合(he)物(wu)以穩定硫(liu)(liu)化(hua)膠的(de)各項性能。常(chang)用的(de)設備有開放(fang)式(shi)煉(lian)膠機、捏合(he)機及真(zhen)空密煉(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯(xian)著的(de)(de)(de)(de)特(te)征是高(gao)溫(wen)(wen)(wen)穩定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常(chang)溫(wen)(wen)(wen)下(xia)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度(du)僅是天(tian)然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某(mou)些合成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)一半,但在200℃以上(shang)的(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia),硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)保持一定(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無明(ming)顯(xian)變(bian)化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃(li)化溫(wen)(wen)(wen)度(du)一般(ban)為(wei)-70~-50℃,特(te)殊配方可達(da)-100℃,表明(ming)其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)(you)(you)異。這對航空(kong)、宇航工(gong)業的(de)(de)(de)(de)意義重大。(3)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧、臭(chou)氧及(ji)紫外線等(deng)(deng)十分穩定(ding),在不(bu)加任何添(tian)加劑(ji)的(de)(de)(de)(de)情況下(xia),就具(ju)有(you)優(you)(you)(you)良的(de)(de)(de)(de)耐(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)優(you)(you)(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非常(chang)好。(5)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下(xia)的(de)(de)(de)(de)物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比(bi)(bi)通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但在150℃的(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)(de)低溫(wen)(wen)(wen)下(xia),其物理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優(you)(you)(you)于通(tong)用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及(ji)化學試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通(tong)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具(ju)有(you)中等(deng)(deng)的(de)(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對空(kong)氣(qi)、氮(dan)、氧、二氧化碳等(deng)(deng)氣(qi)體的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)(bi)天(tian)然(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅(xiu),與人體組(zu)(zu)織(zhi)不(bu)粘連,具(ju)有(you)抗凝血(xue)作(zuo)用(yong),對肌體組(zu)(zu)織(zhi)的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特(te)別適合作(zuo)為(wei)醫用(yong)材料。
硅橡膠的用量
據(ju)中國汽(qi)(qi)車(che)(che)工(gong)(gong)業(ye)(ye)協會統計(ji),2012年(nian),汽(qi)(qi)車(che)(che)產(chan)銷分(fen)別達(da)到1927.18萬(wan)(wan)輛和1930.64萬(wan)(wan)輛,同比分(fen)別增長4.63%和4.33%,汽(qi)(qi)車(che)(che)工(gong)(gong)業(ye)(ye)硅(gui)(gui)橡膠(jiao)的用(yong)量約(yue)達(da)2.0萬(wan)(wan)t。根據(ju)觀研天下的新(xin)研究(jiu),增加(jia)有機硅(gui)(gui)材料在(zai)汽(qi)(qi)車(che)(che)零部件方面的用(yong)量,可(ke)以(yi)大幅度(du)提(ti)高汽(qi)(qi)車(che)(che)的安全性(xing)能,因此,汽(qi)(qi)車(che)(che)產(chan)量和單(dan)車(che)(che)用(yong)量水(shui)平的提(ti)高都將(jiang)推(tui)動汽(qi)(qi)車(che)(che)工(gong)(gong)業(ye)(ye)對硅(gui)(gui)橡膠(jiao)需(xu)求(qiu)的增加(jia)。國家(jia)鼓(gu)勵自(zi)主品(pin)牌(pai)的汽(qi)(qi)車(che)(che)發(fa)展(zhan),關鍵(jian)汽(qi)(qi)車(che)(che)零部件實(shi)現自(zi)主化(hua),《2012年(nian)度(du)黨政(zheng)機關公務用(yong)車(che)(che)選(xuan)用(yong)車(che)(che)型目(mu)錄(征求(qiu)意(yi)見稿)》為自(zi)主品(pin)牌(pai)擴(kuo)大在(zai)政(zheng)府采(cai)購的市場份額,為改變目(mu)前國內政(zheng)府采(cai)購以(yi)合資品(pin)牌(pai)產(chan)品(pin)為主的局(ju)面提(ti)供了保障(zhang)(zhang)。促進自(zi)主品(pin)牌(pai)發(fa)展(zhan),國產(chan)汽(qi)(qi)車(che)(che)業(ye)(ye)的繁榮(rong)將(jiang)為汽(qi)(qi)車(che)(che)膠(jiao)的應用(yong)提(ti)供有力保障(zhang)(zhang)。預測未來3年(nian),我(wo)國室溫硫化(hua)硅(gui)(gui)橡膠(jiao)在(zai)汽(qi)(qi)車(che)(che)行業(ye)(ye)將(jiang)以(yi)年(nian)均20%增長。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的(de)非石油基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠,約占非石油基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠消費量的(de)98%。但因為(wei)石油價(jia)(jia)(jia)格(ge)的(de)大幅上漲,同(tong)時我國(guo)在硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)關鍵(jian)原(yuan)料有(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)的(de)生產(chan)技術方面取(qu)得突破,有(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)的(de)生產(chan)技術在2005年前被幾家(jia)跨國(guo)公司壟斷,但目前我國(guo)已發(fa)展(zhan)成(cheng)(cheng)為(wei)全球有(you)(you)機硅(gui)(gui)(gui)單(dan)(dan)體(ti)第1大國(guo),這(zhe)2個方面原(yuan)因使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)價(jia)(jia)(jia)格(ge)從2011年起(qi)開(kai)始低于(yu)石油基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠,僅約為(wei)大宗(zong)石油基(ji)橡(xiang)(xiang)膠的(de)80%~90%,成(cheng)(cheng)為(wei)廉價(jia)(jia)(jia)的(de)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠,并開(kai)始大規模替代(dai)石油基(ji)合(he)成(cheng)(cheng)橡(xiang)(xiang)膠。這(zhe)將極大拓展(zhan)有(you)(you)機硅(gui)(gui)(gui)產(chan)業的(de)市場空間,同(tong)時將帶(dai)動硅(gui)(gui)(gui)油、硅(gui)(gui)(gui)烷偶聯劑和(he)硅(gui)(gui)(gui)樹脂等其他有(you)(you)機硅(gui)(gui)(gui)產(chan)品的(de)消費。