硅橡膠是(shi)指(zhi)主(zhu)鏈(lian)(lian)由硅(gui)(gui)和氧(yang)原(yuan)子(zi)交替構成,硅(gui)(gui)原(yuan)子(zi)上通(tong)常連有兩(liang)個有機基(ji)團的(de)(de)橡(xiang)膠(jiao)。普通(tong)的(de)(de)硅(gui)(gui)橡(xiang)膠(jiao)主(zhu)要由含甲基(ji)和少量乙烯(xi)基(ji)的(de)(de)硅(gui)(gui)氧(yang)鏈(lian)(lian)節組成。苯(ben)基(ji)的(de)(de)引入(ru)可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)高(gao)(gao)、低溫性(xing)(xing)能(neng)(neng),三氟丙基(ji)及(ji)氰基(ji)的(de)(de)引入(ru)則可提(ti)高(gao)(gao)硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)溫及(ji)耐(nai)(nai)油性(xing)(xing)能(neng)(neng)。硅(gui)(gui)橡(xiang)膠(jiao)耐(nai)(nai)低溫性(xing)(xing)能(neng)(neng)良好(hao),一般在(zai)-55℃下仍能(neng)(neng)工作。引入(ru)苯(ben)基(ji)后(hou),可達-73℃。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)耐(nai)(nai)熱性(xing)(xing)能(neng)(neng)也(ye)很突(tu)出,在(zai)180℃下可長期工作,稍高(gao)(gao)于200℃也(ye)能(neng)(neng)承受數周或更長時間仍有彈性(xing)(xing),瞬時可耐(nai)(nai)300℃以上的(de)(de)高(gao)(gao)溫。硅(gui)(gui)橡(xiang)膠(jiao)的(de)(de)透氣性(xing)(xing)好(hao),氧(yang)氣透過率在(zai)合(he)成聚合(he)物中是(shi)較高(gao)(gao)的(de)(de)。此(ci)外,硅(gui)(gui)橡(xiang)膠(jiao)還具有生理惰(duo)性(xing)(xing)、不會(hui)導致凝(ning)血的(de)(de)突(tu)出特(te)性(xing)(xing),因(yin)此(ci)在(zai)醫用(yong)領(ling)域應用(yong)廣泛(fan)。
主要品種
硅橡膠(jiao)分類的方(fang)法很(hen)多,通常按固化(hua)前的形態(tai)分為(wei)固體(ti)硅橡膠(jiao)和液體(ti)硅橡膠(jiao);按硫(liu)化(hua)溫(wen)(wen)度分為(wei)室(shi)溫(wen)(wen)硫(liu)化(hua)硅橡膠(jiao),高溫(wen)(wen)硫(liu)化(hua)硅橡膠(jiao);按所用單體(ti)的不同(tong),可分為(wei)甲基(ji)乙(yi)烯基(ji)硅橡膠(jiao),甲基(ji)苯基(ji)乙(yi)烯基(ji)硅橡膠(jiao)、氟硅,腈硅橡膠(jiao)等(deng);按性能和用途的不同(tong)又可分為(wei)通用型、超耐(nai)(nai)低溫(wen)(wen)型、超耐(nai)(nai)高溫(wen)(wen)型、高強力型、耐(nai)(nai)油型、醫用型等(deng)等(deng)。
發展史
硅(gui)橡(xiang)(xiang)膠(jiao)早期是由美國(guo)(guo)以三氯化(hua)鐵為催化(hua)劑(ji)合成的。1945年(nian),硅(gui)橡(xiang)(xiang)膠(jiao)產品(pin)問(wen)世。1948年(nian),采用高(gao)比(bi)表面積(ji)的氣(qi)相法白(bai)炭黑補強的硅(gui)橡(xiang)(xiang)膠(jiao)研(yan)(yan)制(zhi)成功,使硅(gui)橡(xiang)(xiang)膠(jiao)的性能躍升到(dao)實用階段(duan),奠定了現(xian)代硅(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產技術(shu)的基礎。從二甲基二氯硅(gui)烷合成開始(shi)生(sheng)產硅(gui)橡(xiang)(xiang)膠(jiao)的國(guo)(guo)家有美國(guo)(guo)。俄(e)羅斯、德國(guo)(guo)、日(ri)本、韓國(guo)(guo)和(he)(he)中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)的工(gong)業化(hua)研(yan)(yan)究始(shi)于(yu)1957年(nian),多家研(yan)(yan)究所和(he)(he)企(qi)業陸(lu)續開發(fa)出各種硅(gui)橡(xiang)(xiang)膠(jiao)。到(dao)2003年(nian)底,中(zhong)國(guo)(guo)硅(gui)橡(xiang)(xiang)膠(jiao)生(sheng)產能力為135千噸,其中(zhong)高(gao)溫膠(jiao)100千噸。
高溫硫化硅橡(xiang)膠
高溫硫(liu)化(hua)(hua)(hua)硅(gui)橡膠(jiao)(jiao)是指聚(ju)硅(gui)氧(yang)(yang)烷(wan)變成(cheng)彈性體(ti)的(de)過程是經過高溫(110-170℃)硫(liu)化(hua)(hua)(hua)成(cheng)型的(de)。它主要以高分子量的(de)聚(ju)甲(jia)基乙烯基硅(gui)氧(yang)(yang)烷(wan)為生膠(jiao)(jiao),混入補強(qiang)填料(liao)、硫(liu)化(hua)(hua)(hua)劑等,在加(jia)熱加(jia)壓下硫(liu)化(hua)(hua)(hua)成(cheng)彈性體(ti)。硅(gui)橡膠(jiao)(jiao)的(de)補強(qiang)主要是各(ge)(ge)(ge)(ge)種類型的(de)白炭黑(hei),可使硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)的(de)強(qiang)度增加(jia)數十倍。有(you)時為了降低成(cheng)本或改善膠(jiao)(jiao)料(liao)性能及賦予(yu)硫(liu)化(hua)(hua)(hua)膠(jiao)(jiao)各(ge)(ge)(ge)(ge)種特殊(shu)的(de)性能,也加(jia)入相應(ying)的(de)各(ge)(ge)(ge)(ge)種添(tian)加(jia)劑。硫(liu)化(hua)(hua)(hua)劑是各(ge)(ge)(ge)(ge)種有(you)機過氧(yang)(yang)化(hua)(hua)(hua)物(wu)或加(jia)成(cheng)反應(ying)催(cui)化(hua)(hua)(hua)劑。
加工成(cheng)型方法如圖(tu)所示。一次硫化(hua)的目的是進行(xing)高分子(zi)鏈的交(jiao)聯(lian)反應;二次硫化(hua)的目的是進行(xing)補充交(jiao)聯(lian)、驅除硫化(hua)劑分解(jie)產物和其他(ta)揮發性化(hua)合(he)物以(yi)穩(wen)定硫化(hua)膠(jiao)的各項性能(neng)。常用的設(she)備有開放式煉膠(jiao)機、捏合(he)機及真空密(mi)煉機。
主要性能
(1)高(gao)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)顯(xian)著的(de)(de)特征是(shi)高(gao)溫(wen)(wen)(wen)穩定(ding)(ding)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常(chang)溫(wen)(wen)(wen)下硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)強度僅是(shi)天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)或(huo)某些合成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)一半,但在(zai)200℃以(yi)上的(de)(de)高(gao)溫(wen)(wen)(wen)環(huan)境下,硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)保持一定(ding)(ding)的(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(biao)面硬度,且力學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)無(wu)明(ming)顯(xian)變(bian)化。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)的(de)(de)玻璃(li)化溫(wen)(wen)(wen)度一般為-70~-50℃,特殊配方可達-100℃,表(biao)明(ming)其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優異(yi)。這對(dui)(dui)航(hang)空、宇(yu)航(hang)工業的(de)(de)意義重大(da)。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵(jian)對(dui)(dui)氧(yang)(yang)、臭氧(yang)(yang)及紫外(wai)線等(deng)十分穩定(ding)(ding),在(zai)不加(jia)(jia)任何(he)添(tian)加(jia)(jia)劑的(de)(de)情況下,就(jiu)具(ju)有(you)(you)(you)優良的(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)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)(you)(you)優異(yi)的(de)(de)絕(jue)緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(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(chang)好。(5)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下的(de)(de)物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)比通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)差(cha),但在(zai)150℃的(de)(de)高(gao)溫(wen)(wen)(wen)和-50℃的(de)(de)低溫(wen)(wen)(wen)下,其物理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)優于通用(yong)(yong)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化學試劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普通硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)具(ju)有(you)(you)(you)中等(deng)的(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。(7)氣(qi)體透(tou)過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)。室(shi)溫(wen)(wen)(wen)下硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)對(dui)(dui)空氣(qi)、氮、氧(yang)(yang)、二氧(yang)(yang)化碳等(deng)氣(qi)體的(de)(de)透(tou)氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅,與人體組(zu)織(zhi)(zhi)不粘連,具(ju)有(you)(you)(you)抗凝血作用(yong)(yong),對(dui)(dui)肌體組(zu)織(zhi)(zhi)的(de)(de)反應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常(chang)少。特別適合作為醫用(yong)(yong)材料。
硅橡膠的用量
據中國(guo)汽(qi)車(che)(che)工業協會統計,2012年,汽(qi)車(che)(che)產(chan)銷分別達到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同比分別增(zeng)長4.63%和(he)4.33%,汽(qi)車(che)(che)工業硅(gui)橡膠的(de)用量約達2.0萬(wan)t。根據觀(guan)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)零(ling)(ling)部件(jian)方面的(de)用量,可以大幅度提(ti)高汽(qi)車(che)(che)的(de)安全性(xing)能,因此,汽(qi)車(che)(che)產(chan)量和(he)單車(che)(che)用量水平(ping)的(de)提(ti)高都將(jiang)推動汽(qi)車(che)(che)工業對(dui)硅(gui)橡膠需求的(de)增(zeng)加。國(guo)家鼓勵自(zi)主品(pin)(pin)牌的(de)汽(qi)車(che)(che)發展,關(guan)鍵汽(qi)車(che)(che)零(ling)(ling)部件(jian)實現自(zi)主化,《2012年度黨政(zheng)機(ji)關(guan)公務(wu)用車(che)(che)選用車(che)(che)型目錄(征(zheng)求意見稿)》為(wei)自(zi)主品(pin)(pin)牌擴大在政(zheng)府采(cai)購(gou)的(de)市場份額(e),為(wei)改變目前國(guo)內政(zheng)府采(cai)購(gou)以合(he)資品(pin)(pin)牌產(chan)品(pin)(pin)為(wei)主的(de)局面提(ti)供了保障。促(cu)進(jin)自(zi)主品(pin)(pin)牌發展,國(guo)產(chan)汽(qi)車(che)(che)業的(de)繁榮將(jiang)為(wei)汽(qi)車(che)(che)膠的(de)應用提(ti)供有力保障。預測未(wei)來3年,我國(guo)室溫硫化硅(gui)橡膠在汽(qi)車(che)(che)行業將(jiang)以年均20%增(zeng)長。
此外(wai),硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)是重要的(de)(de)(de)非(fei)(fei)石(shi)油(you)(you)(you)基(ji)(ji)(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),約占非(fei)(fei)石(shi)油(you)(you)(you)基(ji)(ji)(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)消費量的(de)(de)(de)98%。但(dan)因為(wei)石(shi)油(you)(you)(you)價格的(de)(de)(de)大(da)幅上漲,同(tong)時(shi)我國(guo)在(zai)硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)關鍵(jian)原料(liao)有(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單體的(de)(de)(de)生(sheng)(sheng)產技術方(fang)面取得突破,有(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單體的(de)(de)(de)生(sheng)(sheng)產技術在(zai)2005年(nian)前被幾家跨國(guo)公司壟斷,但(dan)目前我國(guo)已發展成(cheng)(cheng)(cheng)為(wei)全球(qiu)有(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)單體第1大(da)國(guo),這(zhe)2個方(fang)面原因使硅(gui)(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)價格從2011年(nian)起開始(shi)低于石(shi)油(you)(you)(you)基(ji)(ji)(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),僅約為(wei)大(da)宗石(shi)油(you)(you)(you)基(ji)(ji)(ji)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)(de)80%~90%,成(cheng)(cheng)(cheng)為(wei)廉價的(de)(de)(de)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao),并開始(shi)大(da)規模替代石(shi)油(you)(you)(you)基(ji)(ji)(ji)合(he)成(cheng)(cheng)(cheng)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)。這(zhe)將極大(da)拓展有(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)產業的(de)(de)(de)市場空間,同(tong)時(shi)將帶(dai)動(dong)硅(gui)(gui)(gui)(gui)(gui)油(you)(you)(you)、硅(gui)(gui)(gui)(gui)(gui)烷偶聯(lian)劑和硅(gui)(gui)(gui)(gui)(gui)樹脂等其他有(you)機(ji)(ji)(ji)硅(gui)(gui)(gui)(gui)(gui)產品的(de)(de)(de)消費。