硅橡膠是指主鏈由硅(gui)(gui)(gui)(gui)(gui)和氧(yang)原子(zi)(zi)交替構成,硅(gui)(gui)(gui)(gui)(gui)原子(zi)(zi)上通(tong)常(chang)連有(you)兩個有(you)機基(ji)團的橡(xiang)(xiang)膠(jiao)。普通(tong)的硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)和少(shao)量乙烯(xi)基(ji)的硅(gui)(gui)(gui)(gui)(gui)氧(yang)鏈節(jie)組(zu)成。苯基(ji)的引入可(ke)提高硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)高、低溫(wen)性(xing)(xing)(xing)能(neng),三氟丙基(ji)及氰(qing)基(ji)的引入則可(ke)提高硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)溫(wen)及耐(nai)油(you)性(xing)(xing)(xing)能(neng)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)耐(nai)低溫(wen)性(xing)(xing)(xing)能(neng)良好(hao),一般在-55℃下(xia)仍(reng)(reng)能(neng)工(gong)(gong)作。引入苯基(ji)后,可(ke)達-73℃。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的耐(nai)熱性(xing)(xing)(xing)能(neng)也很突(tu)出,在180℃下(xia)可(ke)長(chang)期工(gong)(gong)作,稍高于200℃也能(neng)承受(shou)數周或更長(chang)時間仍(reng)(reng)有(you)彈性(xing)(xing)(xing),瞬(shun)時可(ke)耐(nai)300℃以上的高溫(wen)。硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)的透氣性(xing)(xing)(xing)好(hao),氧(yang)氣透過(guo)率在合成聚合物中是較高的。此外,硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)還具有(you)生理惰性(xing)(xing)(xing)、不會導致凝(ning)血的突(tu)出特(te)性(xing)(xing)(xing),因此在醫用(yong)領域(yu)應用(yong)廣泛。
主要品種
硅橡(xiang)(xiang)膠(jiao)分(fen)類(lei)的方法很(hen)多(duo),通常(chang)按(an)固(gu)化前的形態分(fen)為(wei)(wei)固(gu)體(ti)硅橡(xiang)(xiang)膠(jiao)和液體(ti)硅橡(xiang)(xiang)膠(jiao);按(an)硫化溫(wen)(wen)度分(fen)為(wei)(wei)室溫(wen)(wen)硫化硅橡(xiang)(xiang)膠(jiao),高溫(wen)(wen)硫化硅橡(xiang)(xiang)膠(jiao);按(an)所用(yong)單體(ti)的不同,可分(fen)為(wei)(wei)甲(jia)基(ji)乙(yi)烯基(ji)硅橡(xiang)(xiang)膠(jiao),甲(jia)基(ji)苯基(ji)乙(yi)烯基(ji)硅橡(xiang)(xiang)膠(jiao)、氟(fu)硅,腈硅橡(xiang)(xiang)膠(jiao)等(deng);按(an)性能(neng)和用(yong)途的不同又可分(fen)為(wei)(wei)通用(yong)型、超耐低溫(wen)(wen)型、超耐高溫(wen)(wen)型、高強(qiang)力型、耐油型、醫用(yong)型等(deng)等(deng)。
發展史
硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)早期是由(you)美國以三氯化(hua)鐵為(wei)催化(hua)劑合(he)成的(de)。1945年,硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)產品(pin)問世。1948年,采(cai)用(yong)高(gao)比(bi)表面積的(de)氣相法白(bai)炭黑補強的(de)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)研制成功,使(shi)硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)性(xing)能躍升到實用(yong)階段,奠(dian)定了現代硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生產技術的(de)基(ji)礎。從二(er)甲基(ji)二(er)氯硅烷合(he)成開始生產硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)國家(jia)(jia)有美國。俄羅斯、德國、日本、韓國和中(zhong)國等。中(zhong)國硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)工業化(hua)研究始于1957年,多家(jia)(jia)研究所(suo)和企(qi)業陸續開發出各種硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。到2003年底,中(zhong)國硅橡(xiang)(xiang)膠(jiao)(jiao)(jiao)生產能力為(wei)135千噸(dun),其(qi)中(zhong)高(gao)溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫化(hua)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)是(shi)(shi)指(zhi)聚硅(gui)氧(yang)烷(wan)(wan)變成(cheng)彈性(xing)體的(de)過(guo)程是(shi)(shi)經過(guo)高溫(110-170℃)硫化(hua)成(cheng)型的(de)。它主要(yao)以(yi)高分子量的(de)聚甲(jia)基乙烯基硅(gui)氧(yang)烷(wan)(wan)為生膠(jiao)(jiao)(jiao),混入補強(qiang)填料、硫化(hua)劑(ji)等,在加熱(re)加壓下硫化(hua)成(cheng)彈性(xing)體。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)補強(qiang)主要(yao)是(shi)(shi)各(ge)種(zhong)類型的(de)白炭(tan)黑(hei),可使硫化(hua)膠(jiao)(jiao)(jiao)的(de)強(qiang)度增加數(shu)十倍。有(you)時為了(le)降低(di)成(cheng)本或改善(shan)膠(jiao)(jiao)(jiao)料性(xing)能及賦予硫化(hua)膠(jiao)(jiao)(jiao)各(ge)種(zhong)特殊的(de)性(xing)能,也加入相應的(de)各(ge)種(zhong)添加劑(ji)。硫化(hua)劑(ji)是(shi)(shi)各(ge)種(zhong)有(you)機過(guo)氧(yang)化(hua)物或加成(cheng)反應催化(hua)劑(ji)。
加工成型方法如圖所示。一次硫(liu)化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行高分(fen)子鏈的(de)(de)(de)交聯(lian)反應;二次硫(liu)化(hua)(hua)的(de)(de)(de)目的(de)(de)(de)是(shi)進行補充交聯(lian)、驅(qu)除硫(liu)化(hua)(hua)劑分(fen)解產(chan)物(wu)(wu)和其(qi)他揮發(fa)性(xing)化(hua)(hua)合物(wu)(wu)以穩定(ding)硫(liu)化(hua)(hua)膠的(de)(de)(de)各(ge)項性(xing)能。常用的(de)(de)(de)設備有開放式煉膠機、捏合機及真空密煉機。
主要性能
(1)高(gao)(gao)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)特(te)征是(shi)高(gao)(gao)溫(wen)(wen)穩(wen)定(ding)性(xing)(xing)(xing)(xing)(xing)(xing),雖然(ran)(ran)常溫(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度(du)僅是(shi)天然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)一半(ban),但(dan)在200℃以上的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)環(huan)境下(xia)(xia),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)保持一定(ding)的(de)(de)(de)(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)、回彈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)表面(mian)硬(ying)度(du),且(qie)力學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)無明顯變(bian)化。(2)低(di)(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃化溫(wen)(wen)度(du)一般為-70~-50℃,特(te)殊(shu)配(pei)方可達(da)-100℃,表明其(qi)低(di)(di)溫(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優異。這對(dui)航(hang)空、宇航(hang)工業的(de)(de)(de)(de)意(yi)義重大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對(dui)氧(yang)、臭氧(yang)及(ji)紫外線等十(shi)分穩(wen)定(ding),在不(bu)加(jia)任何添加(jia)劑(ji)的(de)(de)(de)(de)情況下(xia)(xia),就具有(you)優良的(de)(de)(de)(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)優異的(de)(de)(de)(de)絕緣(yuan)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng),耐(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)(xing)和(he)(he)耐(nai)電(dian)弧性(xing)(xing)(xing)(xing)(xing)(xing)也非(fei)(fei)常好。(5)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)下(xia)(xia)的(de)(de)(de)(de)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)比(bi)通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)和(he)(he)-50℃的(de)(de)(de)(de)低(di)(di)溫(wen)(wen)下(xia)(xia),其(qi)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)優于(yu)通用(yong)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化學(xue)試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)具有(you)中等的(de)(de)(de)(de)耐(nai)油、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)。室溫(wen)(wen)下(xia)(xia)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)對(dui)空氣(qi)、氮、氧(yang)、二(er)氧(yang)化碳等氣(qi)體(ti)的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)比(bi)天然(ran)(ran)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)高(gao)(gao)出(chu)30-50倍(bei)。(8)生(sheng)理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)(jiao)無毒,無味(wei),無嗅,與人體(ti)組織(zhi)不(bu)粘(zhan)連(lian),具有(you)抗凝血作(zuo)用(yong),對(dui)肌體(ti)組織(zhi)的(de)(de)(de)(de)反應(ying)性(xing)(xing)(xing)(xing)(xing)(xing)非(fei)(fei)常少(shao)。特(te)別(bie)適合作(zuo)為醫用(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)(qi)車(che)工業協會統計,2012年,汽(qi)(qi)(qi)車(che)產(chan)銷分(fen)別達到1927.18萬(wan)輛和(he)(he)1930.64萬(wan)輛,同比分(fen)別增長4.63%和(he)(he)4.33%,汽(qi)(qi)(qi)車(che)工業硅(gui)橡(xiang)膠的(de)(de)(de)用(yong)(yong)(yong)(yong)量(liang)(liang)約達2.0萬(wan)t。根據觀(guan)研天下的(de)(de)(de)新研究,增加有機硅(gui)材料在(zai)(zai)汽(qi)(qi)(qi)車(che)零(ling)部(bu)件方面(mian)(mian)的(de)(de)(de)用(yong)(yong)(yong)(yong)量(liang)(liang),可以大(da)幅度提(ti)高汽(qi)(qi)(qi)車(che)的(de)(de)(de)安全(quan)性能,因此,汽(qi)(qi)(qi)車(che)產(chan)量(liang)(liang)和(he)(he)單車(che)用(yong)(yong)(yong)(yong)量(liang)(liang)水平(ping)的(de)(de)(de)提(ti)高都(dou)將推動汽(qi)(qi)(qi)車(che)工業對硅(gui)橡(xiang)膠需求(qiu)的(de)(de)(de)增加。國(guo)家鼓勵自(zi)(zi)主(zhu)品(pin)牌(pai)的(de)(de)(de)汽(qi)(qi)(qi)車(che)發(fa)展(zhan),關鍵汽(qi)(qi)(qi)車(che)零(ling)部(bu)件實現(xian)自(zi)(zi)主(zhu)化(hua),《2012年度黨政機關公(gong)務用(yong)(yong)(yong)(yong)車(che)選用(yong)(yong)(yong)(yong)車(che)型目錄(征求(qiu)意見稿(gao))》為自(zi)(zi)主(zhu)品(pin)牌(pai)擴大(da)在(zai)(zai)政府采購的(de)(de)(de)市場份(fen)額(e),為改變目前國(guo)內(nei)政府采購以合資(zi)品(pin)牌(pai)產(chan)品(pin)為主(zhu)的(de)(de)(de)局(ju)面(mian)(mian)提(ti)供(gong)了(le)保(bao)障。促進(jin)自(zi)(zi)主(zhu)品(pin)牌(pai)發(fa)展(zhan),國(guo)產(chan)汽(qi)(qi)(qi)車(che)業的(de)(de)(de)繁榮將為汽(qi)(qi)(qi)車(che)膠的(de)(de)(de)應用(yong)(yong)(yong)(yong)提(ti)供(gong)有力保(bao)障。預測未來3年,我國(guo)室溫硫化(hua)硅(gui)橡(xiang)膠在(zai)(zai)汽(qi)(qi)(qi)車(che)行(xing)業將以年均20%增長。
此(ci)外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)是重要的(de)(de)非石(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),約(yue)占(zhan)非石(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)消費(fei)量的(de)(de)98%。但(dan)因為(wei)石(shi)(shi)油(you)價(jia)(jia)(jia)格的(de)(de)大(da)幅上(shang)漲,同時我(wo)國在硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)關(guan)鍵原料有(you)機(ji)硅(gui)單(dan)體的(de)(de)生產技術方(fang)面(mian)取得突破(po),有(you)機(ji)硅(gui)單(dan)體的(de)(de)生產技術在2005年(nian)前被幾家跨(kua)國公司壟斷(duan),但(dan)目前我(wo)國已(yi)發展成(cheng)為(wei)全球有(you)機(ji)硅(gui)單(dan)體第1大(da)國,這(zhe)2個方(fang)面(mian)原因使硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)價(jia)(jia)(jia)格從2011年(nian)起開(kai)始低于石(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),僅(jin)約(yue)為(wei)大(da)宗石(shi)(shi)油(you)基(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)80%~90%,成(cheng)為(wei)廉(lian)價(jia)(jia)(jia)的(de)(de)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao),并開(kai)始大(da)規(gui)模替(ti)代石(shi)(shi)油(you)基(ji)合(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。這(zhe)將極(ji)大(da)拓(tuo)展有(you)機(ji)硅(gui)產業的(de)(de)市(shi)場(chang)空間,同時將帶動硅(gui)油(you)、硅(gui)烷偶聯(lian)劑和硅(gui)樹脂等其他有(you)機(ji)硅(gui)產品的(de)(de)消費(fei)。