
硅橡膠是(shi)指主(zhu)鏈(lian)由硅(gui)和氧原(yuan)子(zi)交替構成(cheng),硅(gui)原(yuan)子(zi)上通常(chang)連有(you)兩個有(you)機基(ji)團的(de)(de)(de)橡(xiang)(xiang)(xiang)膠。普通的(de)(de)(de)硅(gui)橡(xiang)(xiang)(xiang)膠主(zhu)要(yao)由含甲(jia)基(ji)和少量乙(yi)烯基(ji)的(de)(de)(de)硅(gui)氧鏈(lian)節組成(cheng)。苯基(ji)的(de)(de)(de)引入可(ke)提高硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)(nai)高、低(di)溫(wen)性(xing)能(neng)(neng)(neng)(neng),三(san)氟丙基(ji)及氰基(ji)的(de)(de)(de)引入則(ze)可(ke)提高硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)(nai)溫(wen)及耐(nai)(nai)(nai)油性(xing)能(neng)(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)(xiang)膠耐(nai)(nai)(nai)低(di)溫(wen)性(xing)能(neng)(neng)(neng)(neng)良好(hao),一般在-55℃下仍(reng)能(neng)(neng)(neng)(neng)工(gong)(gong)作。引入苯基(ji)后(hou),可(ke)達-73℃。硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)耐(nai)(nai)(nai)熱(re)性(xing)能(neng)(neng)(neng)(neng)也(ye)(ye)很突出(chu),在180℃下可(ke)長期(qi)工(gong)(gong)作,稍高于200℃也(ye)(ye)能(neng)(neng)(neng)(neng)承受數周或更長時間仍(reng)有(you)彈性(xing),瞬時可(ke)耐(nai)(nai)(nai)300℃以上的(de)(de)(de)高溫(wen)。硅(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)(de)透氣性(xing)好(hao),氧氣透過率在合成(cheng)聚合物中是(shi)較高的(de)(de)(de)。此外,硅(gui)橡(xiang)(xiang)(xiang)膠還具有(you)生理(li)惰性(xing)、不會導致凝血(xue)的(de)(de)(de)突出(chu)特(te)性(xing),因此在醫(yi)用(yong)領(ling)域(yu)應用(yong)廣泛。
主要(yao)品種
硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)分(fen)類的(de)方法很多(duo),通(tong)(tong)常按(an)固(gu)化(hua)(hua)前(qian)的(de)形態(tai)分(fen)為(wei)固(gu)體硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)和液體硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)硫化(hua)(hua)溫(wen)度分(fen)為(wei)室(shi)溫(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),高溫(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao);按(an)所(suo)用(yong)單體的(de)不(bu)同(tong)(tong),可分(fen)為(wei)甲基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao),甲基(ji)苯基(ji)乙烯基(ji)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)等(deng);按(an)性能和用(yong)途的(de)不(bu)同(tong)(tong)又可分(fen)為(wei)通(tong)(tong)用(yong)型、超(chao)耐(nai)低(di)溫(wen)型、超(chao)耐(nai)高溫(wen)型、高強力型、耐(nai)油(you)型、醫用(yong)型等(deng)等(deng)。
發展史
硅橡(xiang)膠(jiao)(jiao)早(zao)期是由美國(guo)(guo)(guo)以三(san)氯(lv)化鐵為催(cui)化劑合成的(de)(de)。1945年,硅橡(xiang)膠(jiao)(jiao)產(chan)品問世。1948年,采用(yong)高(gao)(gao)比表面積的(de)(de)氣相法白炭黑補強(qiang)的(de)(de)硅橡(xiang)膠(jiao)(jiao)研制成功,使硅橡(xiang)膠(jiao)(jiao)的(de)(de)性(xing)能(neng)躍升(sheng)到實用(yong)階段(duan),奠定了現(xian)代硅橡(xiang)膠(jiao)(jiao)生產(chan)技術的(de)(de)基(ji)礎。從二甲基(ji)二氯(lv)硅烷合成開始生產(chan)硅橡(xiang)膠(jiao)(jiao)的(de)(de)國(guo)(guo)(guo)家(jia)有(you)美國(guo)(guo)(guo)。俄(e)羅(luo)斯(si)、德國(guo)(guo)(guo)、日本、韓國(guo)(guo)(guo)和中(zhong)(zhong)國(guo)(guo)(guo)等。中(zhong)(zhong)國(guo)(guo)(guo)硅橡(xiang)膠(jiao)(jiao)的(de)(de)工業化研究始于1957年,多(duo)家(jia)研究所和企業陸續開發(fa)出各(ge)種硅橡(xiang)膠(jiao)(jiao)。到2003年底,中(zhong)(zhong)國(guo)(guo)(guo)硅橡(xiang)膠(jiao)(jiao)生產(chan)能(neng)力(li)為135千噸,其中(zhong)(zhong)高(gao)(gao)溫膠(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫硫(liu)化硅(gui)橡膠(jiao)(jiao)(jiao)是(shi)指(zhi)聚(ju)硅(gui)氧烷變(bian)成彈性體(ti)的(de)過程是(shi)經(jing)過高(gao)溫(110-170℃)硫(liu)化成型(xing)的(de)。它主(zhu)要以(yi)高(gao)分子量的(de)聚(ju)甲基乙烯基硅(gui)氧烷為生膠(jiao)(jiao)(jiao),混入(ru)補強填(tian)料、硫(liu)化劑(ji)(ji)等,在加(jia)(jia)熱加(jia)(jia)壓下硫(liu)化成彈性體(ti)。硅(gui)橡膠(jiao)(jiao)(jiao)的(de)補強主(zhu)要是(shi)各種(zhong)類型(xing)的(de)白炭黑,可使(shi)硫(liu)化膠(jiao)(jiao)(jiao)的(de)強度(du)增加(jia)(jia)數(shu)十(shi)倍。有時為了降(jiang)低(di)成本(ben)或(huo)改善(shan)膠(jiao)(jiao)(jiao)料性能(neng)及賦予硫(liu)化膠(jiao)(jiao)(jiao)各種(zhong)特殊的(de)性能(neng),也加(jia)(jia)入(ru)相(xiang)應(ying)的(de)各種(zhong)添加(jia)(jia)劑(ji)(ji)。硫(liu)化劑(ji)(ji)是(shi)各種(zhong)有機(ji)過氧化物(wu)或(huo)加(jia)(jia)成反應(ying)催化劑(ji)(ji)。
加(jia)工成(cheng)型(xing)方法如圖所示。一次(ci)硫(liu)化(hua)(hua)(hua)的目的是進行高(gao)分子(zi)鏈的交聯反(fan)應;二次(ci)硫(liu)化(hua)(hua)(hua)的目的是進行補(bu)充交聯、驅(qu)除(chu)硫(liu)化(hua)(hua)(hua)劑分解產物(wu)和其他揮發(fa)性化(hua)(hua)(hua)合(he)物(wu)以穩(wen)定(ding)硫(liu)化(hua)(hua)(hua)膠的各項(xiang)性能(neng)。常(chang)用的設(she)備有(you)開放式(shi)煉(lian)膠機、捏合(he)機及真空密煉(lian)機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)顯著的(de)(de)(de)特(te)征是(shi)高(gao)溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)強度僅是(shi)天然橡(xiang)(xiang)(xiang)膠(jiao)或某(mou)些(xie)合成橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)一(yi)半,但在(zai)(zai)200℃以上的(de)(de)(de)高(gao)溫(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)仍能(neng)(neng)(neng)保持一(yi)定的(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明顯變化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)的(de)(de)(de)玻璃化溫(wen)(wen)(wen)度一(yi)般為-70~-50℃,特(te)殊配方可達(da)-100℃,表明其(qi)(qi)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優異。這對航空、宇(yu)航工業(ye)的(de)(de)(de)意義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)中Si-O-Si鍵對氧(yang)(yang)(yang)、臭氧(yang)(yang)(yang)及紫外線等(deng)十分(fen)穩定,在(zai)(zai)不加(jia)任(ren)何添加(jia)劑(ji)的(de)(de)(de)情況下,就具(ju)(ju)(ju)有優良的(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)具(ju)(ju)(ju)有優異的(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)常溫(wen)(wen)(wen)下的(de)(de)(de)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比通用橡(xiang)(xiang)(xiang)膠(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)(de)低溫(wen)(wen)(wen)下,其(qi)(qi)物理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優于通用橡(xiang)(xiang)(xiang)膠(jiao)。(6)耐(nai)油(you)及化學(xue)試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)具(ju)(ju)(ju)有中等(deng)的(de)(de)(de)耐(nai)油(you)、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)對空氣(qi)、氮、氧(yang)(yang)(yang)、二氧(yang)(yang)(yang)化碳等(deng)氣(qi)體的(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)膠(jiao)高(gao)出30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)無毒,無味(wei),無嗅,與人體組織(zhi)不粘連,具(ju)(ju)(ju)有抗凝血作用,對肌體組織(zhi)的(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特(te)別適合作為醫用材料。
硅(gui)橡膠的用量
據(ju)中國(guo)汽車(che)工業(ye)(ye)協會統(tong)計,2012年,汽車(che)產銷(xiao)分別達(da)到1927.18萬(wan)輛(liang)和(he)1930.64萬(wan)輛(liang),同比分別增(zeng)長(chang)4.63%和(he)4.33%,汽車(che)工業(ye)(ye)硅(gui)(gui)橡膠的(de)(de)用量(liang)(liang)約達(da)2.0萬(wan)t。根據(ju)觀(guan)研天下的(de)(de)新研究,增(zeng)加有機硅(gui)(gui)材(cai)料在(zai)(zai)汽車(che)零(ling)部(bu)件(jian)方面的(de)(de)用量(liang)(liang),可(ke)以大幅度提(ti)(ti)(ti)高汽車(che)的(de)(de)安全性能,因此(ci),汽車(che)產量(liang)(liang)和(he)單(dan)車(che)用量(liang)(liang)水平的(de)(de)提(ti)(ti)(ti)高都將(jiang)推動汽車(che)工業(ye)(ye)對硅(gui)(gui)橡膠需求的(de)(de)增(zeng)加。國(guo)家鼓勵自(zi)主(zhu)品(pin)(pin)牌(pai)的(de)(de)汽車(che)發展,關鍵汽車(che)零(ling)部(bu)件(jian)實(shi)現自(zi)主(zhu)化,《2012年度黨政機關公務(wu)用車(che)選用車(che)型目(mu)錄(lu)(征求意見稿)》為(wei)自(zi)主(zhu)品(pin)(pin)牌(pai)擴大在(zai)(zai)政府采(cai)購(gou)的(de)(de)市(shi)場份額,為(wei)改變(bian)目(mu)前國(guo)內政府采(cai)購(gou)以合資品(pin)(pin)牌(pai)產品(pin)(pin)為(wei)主(zhu)的(de)(de)局面提(ti)(ti)(ti)供了保障。促(cu)進自(zi)主(zhu)品(pin)(pin)牌(pai)發展,國(guo)產汽車(che)業(ye)(ye)的(de)(de)繁榮將(jiang)為(wei)汽車(che)膠的(de)(de)應(ying)用提(ti)(ti)(ti)供有力(li)保障。預測未來3年,我國(guo)室溫硫化硅(gui)(gui)橡膠在(zai)(zai)汽車(che)行業(ye)(ye)將(jiang)以年均20%增(zeng)長(chang)。
此外,硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)是重(zhong)要(yao)的非石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),約占非石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao)消費量的98%。但(dan)因為(wei)石(shi)(shi)油(you)價格(ge)的大(da)(da)幅上(shang)漲(zhang),同(tong)時(shi)我(wo)國(guo)在硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的關鍵原料有(you)(you)機(ji)硅(gui)單體的生產(chan)技術方(fang)(fang)面取(qu)得突(tu)破,有(you)(you)機(ji)硅(gui)單體的生產(chan)技術在2005年前被幾家跨國(guo)公司壟斷(duan),但(dan)目前我(wo)國(guo)已發展成(cheng)(cheng)為(wei)全球有(you)(you)機(ji)硅(gui)單體第1大(da)(da)國(guo),這(zhe)2個方(fang)(fang)面原因使硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的價格(ge)從2011年起開始低于(yu)石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大(da)(da)宗石(shi)(shi)油(you)基橡(xiang)膠(jiao)(jiao)(jiao)的80%~90%,成(cheng)(cheng)為(wei)廉價的合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao),并開始大(da)(da)規模替代石(shi)(shi)油(you)基合(he)成(cheng)(cheng)橡(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將極(ji)大(da)(da)拓展有(you)(you)機(ji)硅(gui)產(chan)業的市場空間,同(tong)時(shi)將帶動硅(gui)油(you)、硅(gui)烷偶聯劑(ji)和硅(gui)樹脂等(deng)其(qi)他(ta)有(you)(you)機(ji)硅(gui)產(chan)品(pin)的消費。