硅橡膠是指主鏈(lian)由硅(gui)(gui)(gui)和氧原子交替構(gou)成,硅(gui)(gui)(gui)原子上通(tong)常連有兩個有機(ji)基(ji)(ji)團的(de)(de)(de)橡(xiang)膠。普通(tong)的(de)(de)(de)硅(gui)(gui)(gui)橡(xiang)膠主要由含甲基(ji)(ji)和少量(liang)乙烯(xi)基(ji)(ji)的(de)(de)(de)硅(gui)(gui)(gui)氧鏈(lian)節組成。苯基(ji)(ji)的(de)(de)(de)引入(ru)可(ke)提高硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐高、低溫(wen)性(xing)能(neng),三氟(fu)丙基(ji)(ji)及(ji)氰基(ji)(ji)的(de)(de)(de)引入(ru)則(ze)可(ke)提高硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐溫(wen)及(ji)耐油性(xing)能(neng)。硅(gui)(gui)(gui)橡(xiang)膠耐低溫(wen)性(xing)能(neng)良好,一般在-55℃下(xia)(xia)仍(reng)能(neng)工作。引入(ru)苯基(ji)(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)耐熱性(xing)能(neng)也很突出,在180℃下(xia)(xia)可(ke)長(chang)期工作,稍高于200℃也能(neng)承受數(shu)周或更長(chang)時(shi)間仍(reng)有彈性(xing),瞬時(shi)可(ke)耐300℃以上的(de)(de)(de)高溫(wen)。硅(gui)(gui)(gui)橡(xiang)膠的(de)(de)(de)透氣性(xing)好,氧氣透過(guo)率在合(he)成聚合(he)物中是較(jiao)高的(de)(de)(de)。此外,硅(gui)(gui)(gui)橡(xiang)膠還具(ju)有生理惰性(xing)、不會導致(zhi)凝血的(de)(de)(de)突出特性(xing),因此在醫用(yong)領域應(ying)用(yong)廣(guang)泛。
主(zhu)要品種
硅橡膠分類的方法很多,通常按固化
前的形(xing)態分為(wei)(wei)固體(ti)硅(gui)(gui)橡膠(jiao)和(he)液體(ti)硅(gui)(gui)橡膠(jiao);按硫(liu)(liu)化(hua)(hua)溫(wen)度分為(wei)(wei)室溫(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡膠(jiao),高(gao)溫(wen)硫(liu)(liu)化(hua)(hua)硅(gui)(gui)橡膠(jiao);按所用(yong)單體(ti)的不(bu)(bu)同,可(ke)分為(wei)(wei)甲(jia)基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)橡膠(jiao),甲(jia)基(ji)(ji)苯基(ji)(ji)乙(yi)烯基(ji)(ji)硅(gui)(gui)橡膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡膠(jiao)等;按性能和(he)用(yong)途的不(bu)(bu)同又可(ke)分為(wei)(wei)通用(yong)型(xing)(xing)、超耐(nai)低溫(wen)型(xing)(xing)、超耐(nai)高(gao)溫(wen)型(xing)(xing)、高(gao)強力型(xing)(xing)、耐(nai)油型(xing)(xing)、醫用(yong)型(xing)(xing)等等。
發展史(shi)
硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)早期(qi)是由(you)美國以(yi)三(san)氯(lv)化(hua)鐵為催化(hua)劑合成(cheng)(cheng)的(de)。1945年(nian),硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)產品問(wen)世。1948年(nian),采用(yong)高比表(biao)面積(ji)的(de)氣相法(fa)白炭黑(hei)補(bu)強的(de)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)研(yan)制成(cheng)(cheng)功,使硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)性(xing)能躍(yue)升到(dao)實用(yong)階(jie)段,奠定了現代硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)生產技術的(de)基礎。從二甲基二氯(lv)硅烷合成(cheng)(cheng)開(kai)始生產硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)國家有(you)美國。俄(e)羅斯、德國、日本(ben)、韓國和(he)中(zhong)國等。中(zhong)國硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)工業化(hua)研(yan)究始于(yu)1957年(nian),多家研(yan)究所和(he)企(qi)業陸續開(kai)發出各種(zhong)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)國硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)生產能力為135千噸,其中(zhong)高溫膠(jiao)(jiao)(jiao)(jiao)(jiao)100千噸。
高溫硫化硅(gui)橡膠
高(gao)溫(wen)(wen)硫(liu)(liu)化(hua)(hua)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)是指(zhi)聚(ju)硅(gui)氧(yang)烷(wan)變成(cheng)彈性體的(de)(de)過程是經過高(gao)溫(wen)(wen)(110-170℃)硫(liu)(liu)化(hua)(hua)成(cheng)型的(de)(de)。它主要(yao)以高(gao)分子量的(de)(de)聚(ju)甲基(ji)乙烯基(ji)硅(gui)氧(yang)烷(wan)為(wei)生膠(jiao)(jiao)(jiao),混入(ru)補強填(tian)料、硫(liu)(liu)化(hua)(hua)劑(ji)等,在加(jia)(jia)(jia)熱加(jia)(jia)(jia)壓下硫(liu)(liu)化(hua)(hua)成(cheng)彈性體。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)補強主要(yao)是各(ge)(ge)(ge)種(zhong)類型的(de)(de)白炭黑,可使硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)(jiao)的(de)(de)強度增(zeng)加(jia)(jia)(jia)數十倍。有時為(wei)了降(jiang)低成(cheng)本或改善膠(jiao)(jiao)(jiao)料性能(neng)及(ji)賦予硫(liu)(liu)化(hua)(hua)膠(jiao)(jiao)(jiao)各(ge)(ge)(ge)種(zhong)特殊(shu)的(de)(de)性能(neng),也加(jia)(jia)(jia)入(ru)相(xiang)應的(de)(de)各(ge)(ge)(ge)種(zhong)添加(jia)(jia)(jia)劑(ji)。硫(liu)(liu)化(hua)(hua)劑(ji)是各(ge)(ge)(ge)種(zhong)有機過氧(yang)化(hua)(hua)物或加(jia)(jia)(jia)成(cheng)反應催化(hua)(hua)劑(ji)。
加(jia)工成型(xing)方法如圖(tu)所示。一次(ci)硫化(hua)(hua)的(de)目的(de)是(shi)進(jin)行高分子(zi)鏈(lian)的(de)交(jiao)聯(lian)反應;二次(ci)硫化(hua)(hua)的(de)目的(de)是(shi)進(jin)行補(bu)充交(jiao)聯(lian)、驅除硫化(hua)(hua)劑分解(jie)產物和其(qi)他揮(hui)發(fa)性化(hua)(hua)合物以(yi)穩定硫化(hua)(hua)膠的(de)各項性能。常用的(de)設備有開放式煉膠機、捏(nie)合機及真空密煉機。
主(zhu)要性能
(1)高(gao)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)顯著的(de)(de)(de)(de)特征是高(gao)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)常溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)強度僅是天然(ran)橡(xiang)膠(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)一半(ban),但在(zai)(zai)200℃以上的(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)環(huan)境(jing)下(xia)(xia),硅橡(xiang)膠(jiao)(jiao)仍能(neng)(neng)保持一定(ding)(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表面硬度,且(qie)力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明顯變化(hua)。(2)低(di)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅橡(xiang)膠(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)度一般(ban)為-70~-50℃,特殊配(pei)方可(ke)達-100℃,表明其低(di)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)異。這對航(hang)空、宇航(hang)工(gong)業的(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)中Si-O-Si鍵(jian)對氧(yang)、臭(chou)氧(yang)及紫外(wai)線等(deng)十分穩定(ding)(ding),在(zai)(zai)不(bu)加(jia)任何(he)添加(jia)劑(ji)的(de)(de)(de)(de)情況下(xia)(xia),就具(ju)有(you)優(you)(you)良的(de)(de)(de)(de)耐(nai)(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)。硅橡(xiang)膠(jiao)(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),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好。(5)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)常溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)下(xia)(xia)的(de)(de)(de)(de)物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比通用橡(xiang)膠(jiao)(jiao)差,但在(zai)(zai)150℃的(de)(de)(de)(de)高(gao)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)和-50℃的(de)(de)(de)(de)低(di)溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)下(xia)(xia),其物(wu)理(li)機械性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優(you)(you)于(yu)通用橡(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油及化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅橡(xiang)膠(jiao)(jiao)具(ju)有(you)中等(deng)的(de)(de)(de)(de)耐(nai)(nai)油、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體透(tou)過(guo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)(wen)(wen)(wen)(wen)(wen)下(xia)(xia)硅橡(xiang)膠(jiao)(jiao)對空氣(qi)、氮、氧(yang)、二(er)氧(yang)化(hua)碳等(deng)氣(qi)體的(de)(de)(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然(ran)橡(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生(sheng)理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)無毒,無味(wei),無嗅(xiu),與人體組(zu)織不(bu)粘連,具(ju)有(you)抗凝血作用,對肌體組(zu)織的(de)(de)(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少。特別適合作為醫用材料(liao)。
硅橡(xiang)膠的(de)用(yong)量
據(ju)中(zhong)國(guo)汽(qi)(qi)(qi)車(che)(che)工業協會統計,2012年,汽(qi)(qi)(qi)車(che)(che)產(chan)銷(xiao)分別(bie)達(da)到1927.18萬輛和(he)1930.64萬輛,同(tong)比(bi)分別(bie)增(zeng)長(chang)4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)工業硅橡膠(jiao)的用(yong)量約達(da)2.0萬t。根據(ju)觀研(yan)天下(xia)的新研(yan)究,增(zeng)加有(you)(you)機硅材料在汽(qi)(qi)(qi)車(che)(che)零(ling)部件方(fang)面(mian)的用(yong)量,可以大(da)幅度提(ti)高(gao)汽(qi)(qi)(qi)車(che)(che)的安(an)全(quan)性(xing)能,因此,汽(qi)(qi)(qi)車(che)(che)產(chan)量和(he)單車(che)(che)用(yong)量水(shui)平的提(ti)高(gao)都將(jiang)推(tui)動汽(qi)(qi)(qi)車(che)(che)工業對硅橡膠(jiao)需求的增(zeng)加。國(guo)家鼓勵自(zi)主品牌(pai)的汽(qi)(qi)(qi)車(che)(che)發展,關(guan)鍵(jian)汽(qi)(qi)(qi)車(che)(che)零(ling)部件實現自(zi)主化,《2012年度黨(dang)政機關(guan)公務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(征求意見稿)》為自(zi)主品牌(pai)擴大(da)在政府(fu)采購的市場份額,為改變目前(qian)國(guo)內政府(fu)采購以合資品牌(pai)產(chan)品為主的局面(mian)提(ti)供(gong)了保障。促進自(zi)主品牌(pai)發展,國(guo)產(chan)汽(qi)(qi)(qi)車(che)(che)業的繁榮將(jiang)為汽(qi)(qi)(qi)車(che)(che)膠(jiao)的應用(yong)提(ti)供(gong)有(you)(you)力保障。預測未來3年,我國(guo)室溫硫(liu)化硅橡膠(jiao)在汽(qi)(qi)(qi)車(che)(che)行業將(jiang)以年均20%增(zeng)長(chang)。
此外,硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)是(shi)重(zhong)要的(de)(de)非石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),約(yue)占非石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)消費(fei)量的(de)(de)98%。但(dan)因為(wei)石(shi)(shi)(shi)油(you)(you)價格的(de)(de)大(da)(da)(da)幅上漲,同(tong)時(shi)我國在(zai)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)關鍵(jian)原料有(you)機(ji)硅(gui)(gui)(gui)單體的(de)(de)生產技術方面取得突破,有(you)機(ji)硅(gui)(gui)(gui)單體的(de)(de)生產技術在(zai)2005年前被(bei)幾(ji)家跨國公司壟斷,但(dan)目前我國已發(fa)展成(cheng)(cheng)(cheng)為(wei)全球有(you)機(ji)硅(gui)(gui)(gui)單體第1大(da)(da)(da)國,這2個方面原因使(shi)硅(gui)(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)價格從2011年起開(kai)始低于石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),僅約(yue)為(wei)大(da)(da)(da)宗石(shi)(shi)(shi)油(you)(you)基(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉價的(de)(de)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),并開(kai)始大(da)(da)(da)規模(mo)替代(dai)石(shi)(shi)(shi)油(you)(you)基(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。這將(jiang)極(ji)大(da)(da)(da)拓展有(you)機(ji)硅(gui)(gui)(gui)產業的(de)(de)市場空間,同(tong)時(shi)將(jiang)帶動硅(gui)(gui)(gui)油(you)(you)、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹脂等其他(ta)有(you)機(ji)硅(gui)(gui)(gui)產品(pin)的(de)(de)消費(fei)。