
硅橡膠是(shi)指主鏈(lian)由(you)硅(gui)(gui)(gui)和氧(yang)原(yuan)子交替構成(cheng)(cheng),硅(gui)(gui)(gui)原(yuan)子上(shang)通常連(lian)有(you)兩個有(you)機基團的(de)(de)(de)(de)橡(xiang)膠。普通的(de)(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠主要由(you)含甲基和少量(liang)乙烯基的(de)(de)(de)(de)硅(gui)(gui)(gui)氧(yang)鏈(lian)節組成(cheng)(cheng)。苯(ben)基的(de)(de)(de)(de)引入可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)(de)耐高(gao)(gao)、低溫(wen)(wen)性能(neng),三氟丙基及(ji)氰基的(de)(de)(de)(de)引入則可提高(gao)(gao)硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)(de)耐溫(wen)(wen)及(ji)耐油性能(neng)。硅(gui)(gui)(gui)橡(xiang)膠耐低溫(wen)(wen)性能(neng)良(liang)好,一般(ban)在(zai)-55℃下仍(reng)能(neng)工作。引入苯(ben)基后,可達-73℃。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)(de)耐熱性能(neng)也很突出(chu),在(zai)180℃下可長期(qi)工作,稍(shao)高(gao)(gao)于(yu)200℃也能(neng)承受數周或更長時(shi)間仍(reng)有(you)彈性,瞬時(shi)可耐300℃以上(shang)的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)(de)透氣(qi)(qi)性好,氧(yang)氣(qi)(qi)透過(guo)率在(zai)合(he)成(cheng)(cheng)聚合(he)物中是(shi)較(jiao)高(gao)(gao)的(de)(de)(de)(de)。此外(wai),硅(gui)(gui)(gui)橡(xiang)膠還具(ju)有(you)生理惰性、不會(hui)導致(zhi)凝(ning)血的(de)(de)(de)(de)突出(chu)特性,因此在(zai)醫用(yong)領(ling)域(yu)應用(yong)廣泛(fan)。
主要品(pin)種
硅橡膠分類的方法(fa)很多,通(tong)常按固化
前的(de)形(xing)態(tai)分為(wei)固體硅(gui)橡(xiang)(xiang)膠(jiao)和液體硅(gui)橡(xiang)(xiang)膠(jiao);按硫(liu)化溫(wen)(wen)度(du)分為(wei)室溫(wen)(wen)硫(liu)化硅(gui)橡(xiang)(xiang)膠(jiao),高溫(wen)(wen)硫(liu)化硅(gui)橡(xiang)(xiang)膠(jiao);按所用(yong)單體的(de)不同(tong),可分為(wei)甲基(ji)乙(yi)烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao),甲基(ji)苯基(ji)乙(yi)烯基(ji)硅(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui),腈硅(gui)橡(xiang)(xiang)膠(jiao)等(deng);按性能和用(yong)途(tu)的(de)不同(tong)又(you)可分為(wei)通用(yong)型、超耐低溫(wen)(wen)型、超耐高溫(wen)(wen)型、高強力(li)型、耐油型、醫用(yong)型等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)早期是由美國(guo)(guo)以三(san)氯(lv)化鐵為催(cui)化劑合成的。1945年(nian),硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)產(chan)品(pin)問世。1948年(nian),采用高比表面積的氣相法(fa)白炭黑補強的硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)研(yan)制成功,使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的性能躍(yue)升到實用階段,奠(dian)定了(le)現(xian)代硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)生(sheng)(sheng)產(chan)技術的基礎。從二甲(jia)基二氯(lv)硅(gui)(gui)(gui)烷合成開(kai)始生(sheng)(sheng)產(chan)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的國(guo)(guo)家有美國(guo)(guo)。俄羅斯、德國(guo)(guo)、日本、韓(han)國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的工業(ye)化研(yan)究始于1957年(nian),多家研(yan)究所和企業(ye)陸(lu)續開(kai)發出(chu)各種(zhong)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)硅(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)生(sheng)(sheng)產(chan)能力(li)為135千(qian)噸,其中(zhong)高溫膠(jiao)100千(qian)噸。
高溫硫化硅(gui)橡膠
高(gao)(gao)溫硫(liu)化(hua)硅(gui)(gui)橡膠(jiao)是指聚(ju)硅(gui)(gui)氧烷變成(cheng)彈性(xing)體的過程是經過高(gao)(gao)溫(110-170℃)硫(liu)化(hua)成(cheng)型(xing)的。它主(zhu)要以高(gao)(gao)分子量的聚(ju)甲基(ji)乙(yi)烯(xi)基(ji)硅(gui)(gui)氧烷為生膠(jiao),混入補強(qiang)(qiang)(qiang)填料(liao)、硫(liu)化(hua)劑(ji)等,在(zai)加(jia)熱加(jia)壓(ya)下(xia)硫(liu)化(hua)成(cheng)彈性(xing)體。硅(gui)(gui)橡膠(jiao)的補強(qiang)(qiang)(qiang)主(zhu)要是各種(zhong)(zhong)類(lei)型(xing)的白炭(tan)黑,可使(shi)硫(liu)化(hua)膠(jiao)的強(qiang)(qiang)(qiang)度增加(jia)數(shu)十倍。有時為了降低成(cheng)本(ben)或改善膠(jiao)料(liao)性(xing)能及賦予硫(liu)化(hua)膠(jiao)各種(zhong)(zhong)特殊(shu)的性(xing)能,也加(jia)入相應的各種(zhong)(zhong)添(tian)加(jia)劑(ji)。硫(liu)化(hua)劑(ji)是各種(zhong)(zhong)有機過氧化(hua)物或加(jia)成(cheng)反應催化(hua)劑(ji)。
加工成型方法如圖所示(shi)。一次(ci)硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進(jin)行高分子(zi)鏈的(de)(de)(de)交聯(lian)反(fan)應;二(er)次(ci)硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進(jin)行補充交聯(lian)、驅除硫(liu)化(hua)劑分解產(chan)物和其他揮(hui)發性化(hua)合物以(yi)穩定硫(liu)化(hua)膠(jiao)的(de)(de)(de)各項性能。常用的(de)(de)(de)設備有(you)開放(fang)式煉(lian)膠(jiao)機(ji)(ji)、捏合機(ji)(ji)及真空密(mi)煉(lian)機(ji)(ji)。
主要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)特征(zheng)是高(gao)溫(wen)(wen)(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)強度(du)僅是天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)一(yi)半,但在(zai)(zai)200℃以上的(de)高(gao)溫(wen)(wen)(wen)(wen)環境(jing)下(xia)(xia)(xia),硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)保持(chi)一(yi)定(ding)(ding)的(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)(xing)和(he)表面(mian)硬(ying)度(du),且力(li)學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)玻(bo)璃化溫(wen)(wen)(wen)(wen)度(du)一(yi)般為-70~-50℃,特殊(shu)配方可(ke)達-100℃,表明其(qi)(qi)低(di)溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)異(yi)。這對(dui)航(hang)空、宇航(hang)工業的(de)意義重大。(3)耐候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)氧(yang)(yang)(yang)、臭氧(yang)(yang)(yang)及(ji)紫外線等(deng)十(shi)分穩定(ding)(ding),在(zai)(zai)不加任(ren)何(he)添加劑(ji)(ji)的(de)情況下(xia)(xia)(xia),就具有(you)優(you)良的(de)耐候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)(dian)(dian)氣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)優(you)異(yi)的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐電(dian)(dian)(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)耐電(dian)(dian)(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也(ye)非常好(hao)。(5)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)的(de)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)差(cha),但在(zai)(zai)150℃的(de)高(gao)溫(wen)(wen)(wen)(wen)和(he)-50℃的(de)低(di)溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia),其(qi)(qi)物(wu)理機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)于通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐油及(ji)化學(xue)試劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)中等(deng)的(de)耐油、耐溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣體(ti)(ti)(ti)透過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)(xia)(xia)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣、氮、氧(yang)(yang)(yang)、二氧(yang)(yang)(yang)化碳等(deng)氣體(ti)(ti)(ti)的(de)透氣性(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)出30-50倍(bei)。(8)生理惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味,無嗅,與人(ren)體(ti)(ti)(ti)組織(zhi)不粘(zhan)連,具有(you)抗凝血作用(yong),對(dui)肌體(ti)(ti)(ti)組織(zhi)的(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非常少(shao)。特別適合作為醫用(yong)材料(liao)。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)車(che)(che)(che)(che)工業(ye)協會統計,2012年(nian)(nian),汽(qi)(qi)車(che)(che)(che)(che)產銷分(fen)別(bie)達到(dao)1927.18萬(wan)輛(liang)和(he)(he)1930.64萬(wan)輛(liang),同(tong)比分(fen)別(bie)增(zeng)(zeng)長4.63%和(he)(he)4.33%,汽(qi)(qi)車(che)(che)(che)(che)工業(ye)硅橡膠(jiao)的(de)用(yong)(yong)量約達2.0萬(wan)t。根據(ju)觀研天下(xia)的(de)新研究,增(zeng)(zeng)加有機硅材料在汽(qi)(qi)車(che)(che)(che)(che)零部(bu)(bu)件(jian)方面的(de)用(yong)(yong)量,可以大幅度提高汽(qi)(qi)車(che)(che)(che)(che)的(de)安全性能,因(yin)此,汽(qi)(qi)車(che)(che)(che)(che)產量和(he)(he)單車(che)(che)(che)(che)用(yong)(yong)量水平的(de)提高都將推動(dong)汽(qi)(qi)車(che)(che)(che)(che)工業(ye)對硅橡膠(jiao)需求(qiu)的(de)增(zeng)(zeng)加。國(guo)家鼓勵自(zi)主(zhu)(zhu)品牌的(de)汽(qi)(qi)車(che)(che)(che)(che)發展,關(guan)鍵(jian)汽(qi)(qi)車(che)(che)(che)(che)零部(bu)(bu)件(jian)實現(xian)自(zi)主(zhu)(zhu)化,《2012年(nian)(nian)度黨政機關(guan)公務用(yong)(yong)車(che)(che)(che)(che)選用(yong)(yong)車(che)(che)(che)(che)型(xing)目錄(征求(qiu)意見稿(gao))》為(wei)自(zi)主(zhu)(zhu)品牌擴大在政府采購的(de)市場份(fen)額,為(wei)改變目前國(guo)內政府采購以合資品牌產品為(wei)主(zhu)(zhu)的(de)局面提供了保障(zhang)。促(cu)進自(zi)主(zhu)(zhu)品牌發展,國(guo)產汽(qi)(qi)車(che)(che)(che)(che)業(ye)的(de)繁榮將為(wei)汽(qi)(qi)車(che)(che)(che)(che)膠(jiao)的(de)應用(yong)(yong)提供有力保障(zhang)。預測(ce)未來3年(nian)(nian),我國(guo)室溫硫化硅橡膠(jiao)在汽(qi)(qi)車(che)(che)(che)(che)行業(ye)將以年(nian)(nian)均20%增(zeng)(zeng)長。
此外,硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)是重要的非石(shi)(shi)油基合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),約占非石(shi)(shi)油基合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)消費量的98%。但因(yin)為(wei)石(shi)(shi)油價(jia)格的大(da)幅上漲(zhang),同時我國在硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)單體(ti)的生(sheng)產(chan)技術方面(mian)取得突破(po),有(you)(you)機(ji)硅(gui)單體(ti)的生(sheng)產(chan)技術在2005年前被幾家(jia)跨國公司(si)壟斷,但目前我國已發展(zhan)成(cheng)為(wei)全(quan)球有(you)(you)機(ji)硅(gui)單體(ti)第1大(da)國,這2個(ge)方面(mian)原因(yin)使硅(gui)橡(xiang)(xiang)(xiang)膠(jiao)的價(jia)格從2011年起(qi)開(kai)始低于石(shi)(shi)油基合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),僅約為(wei)大(da)宗石(shi)(shi)油基橡(xiang)(xiang)(xiang)膠(jiao)的80%~90%,成(cheng)為(wei)廉價(jia)的合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao),并開(kai)始大(da)規模替(ti)代石(shi)(shi)油基合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)。這將(jiang)極大(da)拓展(zhan)有(you)(you)機(ji)硅(gui)產(chan)業的市場(chang)空間,同時將(jiang)帶動(dong)硅(gui)油、硅(gui)烷偶聯劑(ji)和硅(gui)樹脂等其他(ta)有(you)(you)機(ji)硅(gui)產(chan)品的消費。