
硅橡膠是指主(zhu)鏈由(you)硅(gui)(gui)和氧原(yuan)(yuan)子交替構成,硅(gui)(gui)原(yuan)(yuan)子上通(tong)常連有兩個有機基(ji)(ji)(ji)(ji)團的橡(xiang)膠(jiao)。普通(tong)的硅(gui)(gui)橡(xiang)膠(jiao)主(zhu)要(yao)由(you)含甲基(ji)(ji)(ji)(ji)和少量乙烯基(ji)(ji)(ji)(ji)的硅(gui)(gui)氧鏈節組成。苯(ben)基(ji)(ji)(ji)(ji)的引(yin)入可(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)的耐(nai)高、低(di)溫(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng),三氟丙基(ji)(ji)(ji)(ji)及氰基(ji)(ji)(ji)(ji)的引(yin)入則(ze)可(ke)提高硅(gui)(gui)橡(xiang)膠(jiao)的耐(nai)溫(wen)(wen)及耐(nai)油性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)耐(nai)低(di)溫(wen)(wen)性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)良好(hao),一(yi)般在(zai)-55℃下仍(reng)能(neng)(neng)(neng)(neng)工作(zuo)(zuo)。引(yin)入苯(ben)基(ji)(ji)(ji)(ji)后(hou),可(ke)達(da)-73℃。硅(gui)(gui)橡(xiang)膠(jiao)的耐(nai)熱性(xing)(xing)(xing)能(neng)(neng)(neng)(neng)也很突(tu)出,在(zai)180℃下可(ke)長(chang)期工作(zuo)(zuo),稍高于200℃也能(neng)(neng)(neng)(neng)承受(shou)數周或更長(chang)時間仍(reng)有彈性(xing)(xing)(xing),瞬(shun)時可(ke)耐(nai)300℃以上的高溫(wen)(wen)。硅(gui)(gui)橡(xiang)膠(jiao)的透氣性(xing)(xing)(xing)好(hao),氧氣透過率在(zai)合成聚合物(wu)中(zhong)是較高的。此外(wai),硅(gui)(gui)橡(xiang)膠(jiao)還(huan)具(ju)有生理惰性(xing)(xing)(xing)、不(bu)會導致凝血的突(tu)出特性(xing)(xing)(xing),因此在(zai)醫用領域(yu)應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)分(fen)類的方法很(hen)多,通常按固(gu)化前的形(xing)態分(fen)為固(gu)體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)和液(ye)體硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按硫化溫(wen)(wen)(wen)度分(fen)為室溫(wen)(wen)(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),高(gao)溫(wen)(wen)(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao);按所用單體的不同,可分(fen)為甲基乙烯基硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao),甲基苯基乙烯基硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)等(deng);按性(xing)能(neng)和用途的不同又可分(fen)為通用型(xing)(xing)(xing)(xing)、超(chao)耐(nai)低溫(wen)(wen)(wen)型(xing)(xing)(xing)(xing)、超(chao)耐(nai)高(gao)溫(wen)(wen)(wen)型(xing)(xing)(xing)(xing)、高(gao)強力型(xing)(xing)(xing)(xing)、耐(nai)油型(xing)(xing)(xing)(xing)、醫用型(xing)(xing)(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是(shi)由美國以三氯化(hua)鐵為(wei)催(cui)化(hua)劑合成的(de)(de)。1945年(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品(pin)問世。1948年(nian),采用(yong)高比表面積的(de)(de)氣相法白(bai)炭黑補強的(de)(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研(yan)(yan)制成功,使(shi)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)性能躍(yue)升到(dao)實用(yong)階段,奠定了(le)現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)技術(shu)的(de)(de)基礎。從二甲基二氯硅(gui)(gui)烷合成開始生(sheng)產(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)國家(jia)有美國。俄(e)羅斯、德國、日本、韓國和(he)中國等。中國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)工業(ye)化(hua)研(yan)(yan)究始于1957年(nian),多(duo)家(jia)研(yan)(yan)究所和(he)企(qi)業(ye)陸續開發出各種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中國硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)能力為(wei)135千(qian)噸,其中高溫膠(jiao)(jiao)(jiao)100千(qian)噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)硅(gui)(gui)橡(xiang)膠是(shi)(shi)指聚硅(gui)(gui)氧烷變成彈(dan)性體(ti)(ti)的過(guo)(guo)程是(shi)(shi)經過(guo)(guo)高(gao)溫(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)成型的。它主要以高(gao)分子量的聚甲基乙烯基硅(gui)(gui)氧烷為(wei)生膠,混入補強填料(liao)、硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)劑(ji)等,在加熱加壓(ya)下硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)成彈(dan)性體(ti)(ti)。硅(gui)(gui)橡(xiang)膠的補強主要是(shi)(shi)各(ge)種(zhong)(zhong)類型的白炭黑,可使硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)膠的強度增加數十(shi)倍(bei)。有時為(wei)了降(jiang)低(di)成本(ben)或改善膠料(liao)性能(neng)及賦予(yu)硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)膠各(ge)種(zhong)(zhong)特殊的性能(neng),也加入相應的各(ge)種(zhong)(zhong)添加劑(ji)。硫(liu)(liu)化(hua)(hua)(hua)(hua)(hua)劑(ji)是(shi)(shi)各(ge)種(zhong)(zhong)有機過(guo)(guo)氧化(hua)(hua)(hua)(hua)(hua)物(wu)或加成反應催化(hua)(hua)(hua)(hua)(hua)劑(ji)。
加工(gong)成型方(fang)法如圖所示(shi)。一(yi)次硫(liu)化(hua)(hua)的(de)(de)目的(de)(de)是(shi)進(jin)行高分子鏈的(de)(de)交聯反應;二次硫(liu)化(hua)(hua)的(de)(de)目的(de)(de)是(shi)進(jin)行補(bu)充交聯、驅除(chu)硫(liu)化(hua)(hua)劑(ji)分解產物和其他揮發性(xing)化(hua)(hua)合(he)物以(yi)穩定(ding)硫(liu)化(hua)(hua)膠的(de)(de)各項性(xing)能(neng)。常(chang)用的(de)(de)設(she)備有開放式煉(lian)膠機、捏合(he)機及(ji)真空密煉(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯著的(de)(de)(de)(de)(de)特(te)征(zheng)是高(gao)溫(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)強度僅(jin)是天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某些合(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)一半,但在(zai)200℃以上的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下(xia),硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)(neng)(neng)保持一定的(de)(de)(de)(de)(de)柔(rou)韌性(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明顯變化。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)(de)玻璃化溫(wen)(wen)(wen)度一般為-70~-50℃,特(te)殊配方可達-100℃,表明其(qi)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)異。這對(dui)航空、宇航工業的(de)(de)(de)(de)(de)意(yi)義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中(zhong)(zhong)Si-O-Si鍵對(dui)氧、臭氧及(ji)紫外線(xian)等(deng)十分穩(wen)定,在(zai)不(bu)加任何添加劑(ji)(ji)的(de)(de)(de)(de)(de)情況下(xia),就具(ju)有優(you)良的(de)(de)(de)(de)(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有優(you)異的(de)(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)也(ye)非常(chang)好。(5)物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常(chang)溫(wen)(wen)(wen)下(xia)的(de)(de)(de)(de)(de)物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但在(zai)150℃的(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)(de)(de)低(di)溫(wen)(wen)(wen)下(xia),其(qi)物理機(ji)(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)于通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)(nai)油及(ji)化學試(shi)劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有中(zhong)(zhong)等(deng)的(de)(de)(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)(ji)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)(qi)體透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下(xia)硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對(dui)空氣(qi)(qi)、氮、氧、二氧化碳等(deng)氣(qi)(qi)體的(de)(de)(de)(de)(de)透氣(qi)(qi)性(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)出30-50倍。(8)生(sheng)理惰(duo)性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組(zu)織(zhi)不(bu)粘連,具(ju)有抗凝血作用(yong)(yong),對(dui)肌體組(zu)織(zhi)的(de)(de)(de)(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)非常(chang)少。特(te)別適合(he)作為醫(yi)用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)(guo)(guo)汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)工業(ye)協會(hui)統計,2012年(nian),汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)產銷(xiao)分別達到1927.18萬(wan)(wan)輛和(he)(he)1930.64萬(wan)(wan)輛,同比(bi)分別增(zeng)長4.63%和(he)(he)4.33%,汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)工業(ye)硅(gui)(gui)橡(xiang)膠(jiao)的用(yong)(yong)(yong)(yong)量約達2.0萬(wan)(wan)t。根據觀研天下的新研究,增(zeng)加有(you)機(ji)(ji)硅(gui)(gui)材料在汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)零部件(jian)方面的用(yong)(yong)(yong)(yong)量,可以大幅度(du)提(ti)高汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)的安全性能,因此,汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)產量和(he)(he)單車(che)(che)(che)(che)(che)(che)用(yong)(yong)(yong)(yong)量水(shui)平(ping)的提(ti)高都將推動汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)工業(ye)對硅(gui)(gui)橡(xiang)膠(jiao)需(xu)求的增(zeng)加。國(guo)(guo)(guo)家(jia)鼓勵自(zi)主(zhu)品牌(pai)的汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)發展(zhan),關(guan)鍵汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)零部件(jian)實現自(zi)主(zhu)化,《2012年(nian)度(du)黨政(zheng)機(ji)(ji)關(guan)公務用(yong)(yong)(yong)(yong)車(che)(che)(che)(che)(che)(che)選用(yong)(yong)(yong)(yong)車(che)(che)(che)(che)(che)(che)型目錄(lu)(征求意見稿)》為自(zi)主(zhu)品牌(pai)擴大在政(zheng)府采購(gou)的市(shi)場份額(e),為改變目前國(guo)(guo)(guo)內政(zheng)府采購(gou)以合資品牌(pai)產品為主(zhu)的局面提(ti)供(gong)了(le)保(bao)障。促進(jin)自(zi)主(zhu)品牌(pai)發展(zhan),國(guo)(guo)(guo)產汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)業(ye)的繁榮(rong)將為汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)膠(jiao)的應用(yong)(yong)(yong)(yong)提(ti)供(gong)有(you)力(li)保(bao)障。預測未來3年(nian),我國(guo)(guo)(guo)室溫硫化硅(gui)(gui)橡(xiang)膠(jiao)在汽(qi)(qi)(qi)車(che)(che)(che)(che)(che)(che)行業(ye)將以年(nian)均20%增(zeng)長。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)膠是重要的(de)(de)非石(shi)(shi)(shi)油(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠,約占非石(shi)(shi)(shi)油(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠消(xiao)費(fei)量的(de)(de)98%。但因為石(shi)(shi)(shi)油(you)價格的(de)(de)大(da)(da)(da)幅上漲(zhang),同時(shi)我國在硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)關鍵原料(liao)有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)(dan)體(ti)的(de)(de)生(sheng)(sheng)產(chan)技術方(fang)面取(qu)得突破,有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)(dan)體(ti)的(de)(de)生(sheng)(sheng)產(chan)技術在2005年前(qian)被幾家跨國公司壟斷,但目(mu)前(qian)我國已發展成(cheng)為全球有(you)機(ji)(ji)硅(gui)(gui)(gui)單(dan)(dan)體(ti)第1大(da)(da)(da)國,這(zhe)2個方(fang)面原因使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)膠的(de)(de)價格從2011年起開始(shi)低于石(shi)(shi)(shi)油(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠,僅約為大(da)(da)(da)宗石(shi)(shi)(shi)油(you)基(ji)(ji)橡(xiang)(xiang)膠的(de)(de)80%~90%,成(cheng)為廉價的(de)(de)合(he)(he)成(cheng)橡(xiang)(xiang)膠,并開始(shi)大(da)(da)(da)規模替代石(shi)(shi)(shi)油(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)膠。這(zhe)將極大(da)(da)(da)拓(tuo)展有(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)業的(de)(de)市場空間,同時(shi)將帶(dai)動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑(ji)和硅(gui)(gui)(gui)樹脂(zhi)等其他有(you)機(ji)(ji)硅(gui)(gui)(gui)產(chan)品(pin)的(de)(de)消(xiao)費(fei)。