
硅橡膠是指主鏈由(you)硅(gui)和(he)氧(yang)原子交替(ti)構成,硅(gui)原子上(shang)通常連(lian)有(you)(you)兩個有(you)(you)機基(ji)(ji)團(tuan)的(de)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)。普通的(de)硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)主要(yao)由(you)含甲基(ji)(ji)和(he)少量乙烯基(ji)(ji)的(de)硅(gui)氧(yang)鏈節組(zu)成。苯(ben)(ben)基(ji)(ji)的(de)引(yin)入可提(ti)高硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)高、低溫(wen)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng),三氟(fu)丙基(ji)(ji)及氰基(ji)(ji)的(de)引(yin)入則可提(ti)高硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)溫(wen)及耐(nai)油性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)耐(nai)低溫(wen)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)良(liang)好,一般在-55℃下仍能(neng)(neng)(neng)工作。引(yin)入苯(ben)(ben)基(ji)(ji)后(hou),可達(da)-73℃。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)耐(nai)熱(re)性(xing)(xing)(xing)(xing)能(neng)(neng)(neng)也很突(tu)出(chu)(chu),在180℃下可長(chang)期工作,稍高于(yu)200℃也能(neng)(neng)(neng)承受數周或更(geng)長(chang)時間仍有(you)(you)彈性(xing)(xing)(xing)(xing),瞬時可耐(nai)300℃以上(shang)的(de)高溫(wen)。硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)透氣(qi)性(xing)(xing)(xing)(xing)好,氧(yang)氣(qi)透過率(lv)在合(he)成聚合(he)物中(zhong)是較高的(de)。此外,硅(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)還具有(you)(you)生理(li)惰性(xing)(xing)(xing)(xing)、不會(hui)導致凝血的(de)突(tu)出(chu)(chu)特性(xing)(xing)(xing)(xing),因此在醫用領(ling)域應用廣泛。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)分類的(de)方法很多(duo),通常按(an)固化(hua)(hua)前的(de)形態分為(wei)(wei)固體(ti)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)和液(ye)體(ti)硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)硫化(hua)(hua)溫(wen)度分為(wei)(wei)室溫(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao),高(gao)(gao)溫(wen)硫化(hua)(hua)硅(gui)(gui)橡(xiang)(xiang)膠(jiao);按(an)所用(yong)單體(ti)的(de)不同,可分為(wei)(wei)甲(jia)基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao),甲(jia)基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)膠(jiao)等(deng);按(an)性能(neng)和用(yong)途的(de)不同又可分為(wei)(wei)通用(yong)型(xing)(xing)、超耐低(di)溫(wen)型(xing)(xing)、超耐高(gao)(gao)溫(wen)型(xing)(xing)、高(gao)(gao)強(qiang)力型(xing)(xing)、耐油型(xing)(xing)、醫用(yong)型(xing)(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期是由美(mei)國(guo)(guo)以三氯化(hua)鐵為(wei)(wei)催化(hua)劑合成的(de)。1945年(nian),硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)(chan)(chan)品問(wen)世。1948年(nian),采用高(gao)比表(biao)面積的(de)氣(qi)相法白炭黑(hei)補(bu)強(qiang)的(de)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研制成功,使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)性能(neng)躍升到(dao)實用階段,奠定了現代硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)(chan)技術的(de)基礎。從二甲基二氯硅(gui)(gui)烷(wan)合成開(kai)始生(sheng)產(chan)(chan)(chan)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)國(guo)(guo)家有美(mei)國(guo)(guo)。俄羅斯(si)、德國(guo)(guo)、日(ri)本、韓國(guo)(guo)和中國(guo)(guo)等。中國(guo)(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)工業化(hua)研究(jiu)始于1957年(nian),多(duo)家研究(jiu)所(suo)和企(qi)業陸(lu)續開(kai)發(fa)出各(ge)種硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中國(guo)(guo)硅(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生(sheng)產(chan)(chan)(chan)能(neng)力(li)為(wei)(wei)135千噸,其中高(gao)溫膠(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫(wen)硫(liu)化(hua)(hua)硅橡膠是(shi)指聚硅氧烷變(bian)成(cheng)(cheng)彈性體的(de)(de)過程是(shi)經過高溫(wen)(110-170℃)硫(liu)化(hua)(hua)成(cheng)(cheng)型(xing)的(de)(de)。它(ta)主(zhu)要以(yi)高分子量的(de)(de)聚甲基(ji)乙(yi)烯基(ji)硅氧烷為生膠,混入補強填料(liao)、硫(liu)化(hua)(hua)劑等,在加熱加壓(ya)下硫(liu)化(hua)(hua)成(cheng)(cheng)彈性體。硅橡膠的(de)(de)補強主(zhu)要是(shi)各(ge)種(zhong)(zhong)類(lei)型(xing)的(de)(de)白(bai)炭(tan)黑,可(ke)使硫(liu)化(hua)(hua)膠的(de)(de)強度增加數(shu)十(shi)倍。有時(shi)為了降低成(cheng)(cheng)本(ben)或改善膠料(liao)性能及賦予硫(liu)化(hua)(hua)膠各(ge)種(zhong)(zhong)特殊的(de)(de)性能,也加入相應(ying)的(de)(de)各(ge)種(zhong)(zhong)添加劑。硫(liu)化(hua)(hua)劑是(shi)各(ge)種(zhong)(zhong)有機(ji)過氧化(hua)(hua)物或加成(cheng)(cheng)反應(ying)催化(hua)(hua)劑。
加工成型方(fang)法(fa)如圖所示。一次硫化的目(mu)的是進(jin)行高分子鏈的交聯反應;二次硫化的目(mu)的是進(jin)行補充(chong)交聯、驅(qu)除(chu)硫化劑分解產(chan)物(wu)和其他揮發性(xing)化合(he)物(wu)以穩定硫化膠(jiao)的各項性(xing)能。常用的設備有開放式(shi)煉膠(jiao)機、捏合(he)機及真空密煉機。
主要性能
(1)高(gao)(gao)溫(wen)(wen)(wen)(wen)性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著(zhu)的特征是高(gao)(gao)溫(wen)(wen)(wen)(wen)穩定(ding)性(xing)(xing),雖(sui)然常溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的強度僅是天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成(cheng)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的一(yi)半,但(dan)在200℃以上的高(gao)(gao)溫(wen)(wen)(wen)(wen)環境下(xia),硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保持一(yi)定(ding)的柔韌性(xing)(xing)、回彈性(xing)(xing)和表(biao)面硬度,且力(li)學性(xing)(xing)能(neng)(neng)(neng)無(wu)明(ming)顯變(bian)化。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的玻璃化溫(wen)(wen)(wen)(wen)度一(yi)般為-70~-50℃,特殊配方可(ke)達-100℃,表(biao)明(ming)其(qi)低溫(wen)(wen)(wen)(wen)性(xing)(xing)能(neng)(neng)(neng)優異。這對(dui)(dui)(dui)航(hang)空、宇航(hang)工業的意義(yi)重大(da)。(3)耐(nai)候性(xing)(xing)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)(dui)(dui)氧、臭(chou)氧及(ji)紫外(wai)線等十分穩定(ding),在不加(jia)任何添加(jia)劑的情況下(xia),就具有優良的耐(nai)候性(xing)(xing)。(4)電(dian)(dian)氣(qi)(qi)(qi)性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有優異的絕緣(yuan)性(xing)(xing)能(neng)(neng)(neng),耐(nai)電(dian)(dian)暈性(xing)(xing)和耐(nai)電(dian)(dian)弧性(xing)(xing)也非常好。(5)物理(li)(li)機(ji)械(xie)性(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下(xia)的物理(li)(li)機(ji)械(xie)性(xing)(xing)能(neng)(neng)(neng)比(bi)通(tong)用(yong)(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)在150℃的高(gao)(gao)溫(wen)(wen)(wen)(wen)和-50℃的低溫(wen)(wen)(wen)(wen)下(xia),其(qi)物理(li)(li)機(ji)械(xie)性(xing)(xing)能(neng)(neng)(neng)優于通(tong)用(yong)(yong)(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油及(ji)化學試劑性(xing)(xing)。普通(tong)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有中等的耐(nai)油、耐(nai)溶劑性(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)(qi)(qi)體透過性(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下(xia)硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對(dui)(dui)(dui)空氣(qi)(qi)(qi)、氮、氧、二氧化碳等氣(qi)(qi)(qi)體的透氣(qi)(qi)(qi)性(xing)(xing)比(bi)天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高(gao)(gao)出30-50倍。(8)生理(li)(li)惰性(xing)(xing)。硅(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與人體組織(zhi)(zhi)不粘(zhan)連,具有抗(kang)凝血(xue)作用(yong)(yong)(yong),對(dui)(dui)(dui)肌體組織(zhi)(zhi)的反應性(xing)(xing)非常少。特別適合作為醫用(yong)(yong)(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)(qi)車(che)工(gong)(gong)(gong)業協會統計,2012年(nian)(nian)(nian),汽(qi)(qi)車(che)產(chan)銷分別(bie)達到1927.18萬(wan)輛(liang)和1930.64萬(wan)輛(liang),同比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)工(gong)(gong)(gong)業硅(gui)橡膠(jiao)的(de)(de)(de)(de)用(yong)量(liang)約達2.0萬(wan)t。根據觀研天下的(de)(de)(de)(de)新(xin)研究,增(zeng)加有(you)機硅(gui)材料在汽(qi)(qi)車(che)零(ling)部(bu)件(jian)方(fang)面的(de)(de)(de)(de)用(yong)量(liang),可(ke)以(yi)(yi)大幅(fu)度(du)提(ti)高汽(qi)(qi)車(che)的(de)(de)(de)(de)安(an)全性(xing)能,因此,汽(qi)(qi)車(che)產(chan)量(liang)和單車(che)用(yong)量(liang)水平的(de)(de)(de)(de)提(ti)高都將推(tui)動(dong)汽(qi)(qi)車(che)工(gong)(gong)(gong)業對(dui)硅(gui)橡膠(jiao)需求(qiu)的(de)(de)(de)(de)增(zeng)加。國(guo)家鼓勵自(zi)主(zhu)品牌的(de)(de)(de)(de)汽(qi)(qi)車(che)發展(zhan),關鍵汽(qi)(qi)車(che)零(ling)部(bu)件(jian)實現自(zi)主(zhu)化,《2012年(nian)(nian)(nian)度(du)黨政(zheng)機關公務用(yong)車(che)選用(yong)車(che)型目錄(征求(qiu)意見稿)》為(wei)(wei)自(zi)主(zhu)品牌擴大在政(zheng)府采(cai)購的(de)(de)(de)(de)市場份額,為(wei)(wei)改變目前國(guo)內政(zheng)府采(cai)購以(yi)(yi)合資品牌產(chan)品為(wei)(wei)主(zhu)的(de)(de)(de)(de)局面提(ti)供了保障。促進(jin)自(zi)主(zhu)品牌發展(zhan),國(guo)產(chan)汽(qi)(qi)車(che)業的(de)(de)(de)(de)繁榮(rong)將為(wei)(wei)汽(qi)(qi)車(che)膠(jiao)的(de)(de)(de)(de)應用(yong)提(ti)供有(you)力(li)保障。預(yu)測未來(lai)3年(nian)(nian)(nian),我國(guo)室溫硫化硅(gui)橡膠(jiao)在汽(qi)(qi)車(che)行業將以(yi)(yi)年(nian)(nian)(nian)均20%增(zeng)長。
此外,硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)是(shi)重要的(de)(de)(de)非石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),約占(zhan)非石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)消(xiao)費量的(de)(de)(de)98%。但(dan)因(yin)為(wei)石(shi)(shi)油(you)(you)(you)價(jia)格的(de)(de)(de)大(da)(da)(da)幅上漲,同(tong)時我(wo)國(guo)在(zai)硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)關(guan)鍵原料有(you)(you)(you)機(ji)(ji)硅單體的(de)(de)(de)生產技(ji)術方(fang)面取得突(tu)破(po),有(you)(you)(you)機(ji)(ji)硅單體的(de)(de)(de)生產技(ji)術在(zai)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(zhan)成(cheng)為(wei)全球有(you)(you)(you)機(ji)(ji)硅單體第(di)1大(da)(da)(da)國(guo),這2個(ge)方(fang)面原因(yin)使硅橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)價(jia)格從(cong)2011年起開始低(di)于(yu)石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),僅約為(wei)大(da)(da)(da)宗石(shi)(shi)油(you)(you)(you)基(ji)(ji)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)為(wei)廉價(jia)的(de)(de)(de)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao),并開始大(da)(da)(da)規(gui)模替代石(shi)(shi)油(you)(you)(you)基(ji)(ji)合(he)(he)成(cheng)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。這將極大(da)(da)(da)拓展(zhan)有(you)(you)(you)機(ji)(ji)硅產業(ye)的(de)(de)(de)市場空間(jian),同(tong)時將帶(dai)動硅油(you)(you)(you)、硅烷偶聯(lian)劑和(he)硅樹(shu)脂等其(qi)他有(you)(you)(you)機(ji)(ji)硅產品(pin)的(de)(de)(de)消(xiao)費。