
硅橡膠是指(zhi)主(zhu)鏈由硅和氧原子交(jiao)替(ti)構成(cheng),硅原子上(shang)通(tong)常(chang)連有(you)兩個(ge)有(you)機基(ji)團的(de)橡(xiang)(xiang)(xiang)(xiang)(xiang)膠。普通(tong)的(de)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠主(zhu)要由含甲基(ji)和少量乙烯基(ji)的(de)硅氧鏈節組成(cheng)。苯基(ji)的(de)引入可(ke)(ke)提高(gao)(gao)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)耐高(gao)(gao)、低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)能(neng)(neng),三氟(fu)丙基(ji)及氰(qing)基(ji)的(de)引入則(ze)可(ke)(ke)提高(gao)(gao)硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)耐溫及耐油(you)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠耐低(di)(di)溫性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)良好,一般在-55℃下(xia)(xia)仍能(neng)(neng)工作(zuo)。引入苯基(ji)后,可(ke)(ke)達-73℃。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)耐熱性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)也很突出,在180℃下(xia)(xia)可(ke)(ke)長期工作(zuo),稍高(gao)(gao)于(yu)200℃也能(neng)(neng)承受數周或更長時間仍有(you)彈(dan)性(xing)(xing)(xing)(xing)(xing),瞬時可(ke)(ke)耐300℃以上(shang)的(de)高(gao)(gao)溫。硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠的(de)透(tou)氣性(xing)(xing)(xing)(xing)(xing)好,氧氣透(tou)過率(lv)在合成(cheng)聚合物(wu)中是較高(gao)(gao)的(de)。此(ci)外(wai),硅橡(xiang)(xiang)(xiang)(xiang)(xiang)膠還(huan)具有(you)生(sheng)理惰性(xing)(xing)(xing)(xing)(xing)、不(bu)會導(dao)致凝血的(de)突出特性(xing)(xing)(xing)(xing)(xing),因此(ci)在醫用領(ling)域應用廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)膠(jiao)分(fen)(fen)類的(de)(de)方法很多,通(tong)常按固化前的(de)(de)形態分(fen)(fen)為固體(ti)硅(gui)(gui)橡(xiang)膠(jiao)和(he)液(ye)體(ti)硅(gui)(gui)橡(xiang)膠(jiao);按硫化溫(wen)度分(fen)(fen)為室溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao),高溫(wen)硫化硅(gui)(gui)橡(xiang)膠(jiao);按所用(yong)單體(ti)的(de)(de)不同(tong)(tong),可分(fen)(fen)為甲(jia)基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao),甲(jia)基(ji)(ji)苯基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)膠(jiao)等(deng)(deng);按性能和(he)用(yong)途的(de)(de)不同(tong)(tong)又可分(fen)(fen)為通(tong)用(yong)型、超耐(nai)低溫(wen)型、超耐(nai)高溫(wen)型、高強力型、耐(nai)油型、醫用(yong)型等(deng)(deng)等(deng)(deng)。
發展史
硅(gui)(gui)(gui)(gui)橡膠早(zao)期是(shi)由美國(guo)以三(san)氯化鐵為催化劑合成(cheng)(cheng)的(de)(de)。1945年,硅(gui)(gui)(gui)(gui)橡膠產(chan)品問(wen)世(shi)。1948年,采(cai)用高(gao)比表面(mian)積的(de)(de)氣(qi)相法白炭黑補強的(de)(de)硅(gui)(gui)(gui)(gui)橡膠研(yan)制成(cheng)(cheng)功,使硅(gui)(gui)(gui)(gui)橡膠的(de)(de)性能躍(yue)升到實用階段,奠定了現代硅(gui)(gui)(gui)(gui)橡膠生產(chan)技(ji)術的(de)(de)基礎。從二甲基二氯硅(gui)(gui)(gui)(gui)烷合成(cheng)(cheng)開(kai)始生產(chan)硅(gui)(gui)(gui)(gui)橡膠的(de)(de)國(guo)家(jia)有美國(guo)。俄羅斯、德國(guo)、日(ri)本(ben)、韓國(guo)和中(zhong)國(guo)等(deng)。中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡膠的(de)(de)工(gong)業(ye)化研(yan)究(jiu)始于1957年,多家(jia)研(yan)究(jiu)所和企業(ye)陸續開(kai)發出各種(zhong)硅(gui)(gui)(gui)(gui)橡膠。到2003年底,中(zhong)國(guo)硅(gui)(gui)(gui)(gui)橡膠生產(chan)能力(li)為135千噸(dun),其中(zhong)高(gao)溫膠100千噸(dun)。
高溫硫化硅橡膠
高(gao)溫硫化(hua)(hua)硅橡膠(jiao)是(shi)指聚硅氧(yang)烷變成(cheng)彈(dan)性體的(de)(de)(de)過(guo)(guo)程是(shi)經過(guo)(guo)高(gao)溫(110-170℃)硫化(hua)(hua)成(cheng)型的(de)(de)(de)。它主要以高(gao)分子量的(de)(de)(de)聚甲基乙烯(xi)基硅氧(yang)烷為生膠(jiao),混入補強填料、硫化(hua)(hua)劑(ji)等(deng),在加(jia)熱加(jia)壓(ya)下硫化(hua)(hua)成(cheng)彈(dan)性體。硅橡膠(jiao)的(de)(de)(de)補強主要是(shi)各(ge)種(zhong)類型的(de)(de)(de)白(bai)炭(tan)黑,可使硫化(hua)(hua)膠(jiao)的(de)(de)(de)強度增加(jia)數十倍。有(you)時為了降(jiang)低成(cheng)本或(huo)改善膠(jiao)料性能及(ji)賦予硫化(hua)(hua)膠(jiao)各(ge)種(zhong)特殊的(de)(de)(de)性能,也加(jia)入相(xiang)應的(de)(de)(de)各(ge)種(zhong)添加(jia)劑(ji)。硫化(hua)(hua)劑(ji)是(shi)各(ge)種(zhong)有(you)機過(guo)(guo)氧(yang)化(hua)(hua)物或(huo)加(jia)成(cheng)反應催化(hua)(hua)劑(ji)。
加工(gong)成型方法如圖所(suo)示。一(yi)次硫化(hua)的(de)目(mu)的(de)是進行高分(fen)(fen)子鏈的(de)交(jiao)聯反應;二次硫化(hua)的(de)目(mu)的(de)是進行補(bu)充交(jiao)聯、驅除硫化(hua)劑分(fen)(fen)解產物(wu)和其他(ta)揮發性化(hua)合物(wu)以穩定(ding)硫化(hua)膠(jiao)的(de)各項性能。常用的(de)設(she)備有開(kai)放式(shi)煉膠(jiao)機(ji)、捏合機(ji)及真空(kong)密煉機(ji)。
主要性能
(1)高(gao)溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)顯(xian)著的(de)(de)(de)(de)特征是高(gao)溫(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)強度(du)僅是天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)或某些合(he)成(cheng)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)一(yi)半,但(dan)(dan)在(zai)(zai)200℃以上的(de)(de)(de)(de)高(gao)溫(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)(neng)(neng)保持一(yi)定的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度(du),且(qie)力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無明顯(xian)變化(hua)。(2)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)(de)玻璃化(hua)溫(wen)度(du)一(yi)般為(wei)-70~-50℃,特殊配方可達-100℃,表明其(qi)低溫(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)異。這(zhe)對航空(kong)、宇(yu)航工業的(de)(de)(de)(de)意義重(zhong)大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵對氧、臭(chou)氧及(ji)紫外線等十分穩(wen)定,在(zai)(zai)不加任何添加劑(ji)的(de)(de)(de)(de)情(qing)況下,就(jiu)具(ju)有(you)優(you)(you)良(liang)的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)優(you)(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)(fei)常好。(5)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)常溫(wen)下的(de)(de)(de)(de)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)差,但(dan)(dan)在(zai)(zai)150℃的(de)(de)(de)(de)高(gao)溫(wen)和-50℃的(de)(de)(de)(de)低溫(wen)下,其(qi)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優(you)(you)于通(tong)用(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)油及(ji)化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通(tong)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)具(ju)有(you)中等的(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室(shi)溫(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)對空(kong)氣(qi)、氮、氧、二氧化(hua)碳等氣(qi)體(ti)(ti)的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)高(gao)出(chu)30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)無毒,無味(wei),無嗅,與人(ren)體(ti)(ti)組織不粘連(lian),具(ju)有(you)抗(kang)凝血作用(yong),對肌體(ti)(ti)組織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非(fei)(fei)常少。特別適合(he)作為(wei)醫用(yong)材料。
硅橡膠的用量
據(ju)中國汽(qi)車(che)(che)(che)工(gong)業(ye)協會(hui)統計,2012年,汽(qi)車(che)(che)(che)產(chan)銷分別達到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同(tong)比分別增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)車(che)(che)(che)工(gong)業(ye)硅(gui)橡(xiang)膠的(de)用(yong)(yong)(yong)量(liang)約達2.0萬(wan)t。根據(ju)觀研天下的(de)新研究,增(zeng)加有機(ji)硅(gui)材(cai)料在汽(qi)車(che)(che)(che)零部件方面(mian)的(de)用(yong)(yong)(yong)量(liang),可以(yi)(yi)大幅度(du)提高(gao)汽(qi)車(che)(che)(che)的(de)安全性能(neng),因此,汽(qi)車(che)(che)(che)產(chan)量(liang)和(he)單車(che)(che)(che)用(yong)(yong)(yong)量(liang)水(shui)平的(de)提高(gao)都將推(tui)動(dong)汽(qi)車(che)(che)(che)工(gong)業(ye)對硅(gui)橡(xiang)膠需求的(de)增(zeng)加。國家(jia)鼓勵自(zi)(zi)主品(pin)牌(pai)的(de)汽(qi)車(che)(che)(che)發展,關鍵汽(qi)車(che)(che)(che)零部件實現自(zi)(zi)主化(hua),《2012年度(du)黨政(zheng)(zheng)機(ji)關公務用(yong)(yong)(yong)車(che)(che)(che)選用(yong)(yong)(yong)車(che)(che)(che)型(xing)目錄(lu)(征求意見稿)》為(wei)自(zi)(zi)主品(pin)牌(pai)擴(kuo)大在政(zheng)(zheng)府采(cai)購(gou)的(de)市場(chang)份額,為(wei)改變目前國內政(zheng)(zheng)府采(cai)購(gou)以(yi)(yi)合資品(pin)牌(pai)產(chan)品(pin)為(wei)主的(de)局面(mian)提供(gong)了(le)保障。促進自(zi)(zi)主品(pin)牌(pai)發展,國產(chan)汽(qi)車(che)(che)(che)業(ye)的(de)繁榮將為(wei)汽(qi)車(che)(che)(che)膠的(de)應(ying)用(yong)(yong)(yong)提供(gong)有力保障。預測未來3年,我國室溫(wen)硫化(hua)硅(gui)橡(xiang)膠在汽(qi)車(che)(che)(che)行業(ye)將以(yi)(yi)年均20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)是重要的(de)非(fei)石油(you)(you)(you)基合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),約(yue)占(zhan)非(fei)石油(you)(you)(you)基合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)消(xiao)費(fei)量的(de)98%。但因為(wei)石油(you)(you)(you)價格的(de)大(da)(da)(da)幅上漲,同(tong)時(shi)我(wo)國(guo)在硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)關鍵原(yuan)(yuan)料有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體的(de)生產技術(shu)方(fang)面取(qu)得突破,有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體的(de)生產技術(shu)在2005年(nian)前被幾家跨國(guo)公司壟斷,但目前我(wo)國(guo)已(yi)發(fa)展(zhan)成(cheng)(cheng)為(wei)全球有(you)(you)機(ji)硅(gui)(gui)(gui)單(dan)體第1大(da)(da)(da)國(guo),這(zhe)2個(ge)方(fang)面原(yuan)(yuan)因使硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)價格從2011年(nian)起開(kai)(kai)始低(di)于(yu)石油(you)(you)(you)基合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),僅約(yue)為(wei)大(da)(da)(da)宗石油(you)(you)(you)基橡(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)(cheng)為(wei)廉價的(de)合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),并(bing)開(kai)(kai)始大(da)(da)(da)規模替(ti)代石油(you)(you)(you)基合成(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)。這(zhe)將極大(da)(da)(da)拓展(zhan)有(you)(you)機(ji)硅(gui)(gui)(gui)產業(ye)的(de)市場(chang)空間,同(tong)時(shi)將帶動硅(gui)(gui)(gui)油(you)(you)(you)、硅(gui)(gui)(gui)烷偶(ou)聯劑和(he)硅(gui)(gui)(gui)樹脂等其他(ta)有(you)(you)機(ji)硅(gui)(gui)(gui)產品的(de)消(xiao)費(fei)。