
硅橡膠是指主鏈由(you)硅(gui)和氧(yang)(yang)原子交替構成(cheng),硅(gui)原子上通常連有(you)(you)(you)兩個有(you)(you)(you)機基團的(de)(de)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。普通的(de)(de)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)主要(yao)由(you)含甲基和少量乙烯基的(de)(de)硅(gui)氧(yang)(yang)鏈節組(zu)成(cheng)。苯(ben)基的(de)(de)引(yin)入(ru)可提高(gao)(gao)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)耐高(gao)(gao)、低溫性(xing)(xing)(xing)能(neng)(neng)(neng),三氟(fu)丙(bing)基及氰基的(de)(de)引(yin)入(ru)則可提高(gao)(gao)硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)耐溫及耐油性(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)耐低溫性(xing)(xing)(xing)能(neng)(neng)(neng)良好,一般在-55℃下仍能(neng)(neng)(neng)工作。引(yin)入(ru)苯(ben)基后(hou),可達-73℃。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)耐熱性(xing)(xing)(xing)能(neng)(neng)(neng)也很突出(chu),在180℃下可長期工作,稍高(gao)(gao)于200℃也能(neng)(neng)(neng)承(cheng)受數周或更長時間(jian)仍有(you)(you)(you)彈性(xing)(xing)(xing),瞬時可耐300℃以(yi)上的(de)(de)高(gao)(gao)溫。硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)(de)透(tou)(tou)氣(qi)性(xing)(xing)(xing)好,氧(yang)(yang)氣(qi)透(tou)(tou)過(guo)率在合(he)成(cheng)聚合(he)物中是較高(gao)(gao)的(de)(de)。此(ci)外,硅(gui)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)還具(ju)有(you)(you)(you)生理惰性(xing)(xing)(xing)、不會導致凝血的(de)(de)突出(chu)特(te)性(xing)(xing)(xing),因此(ci)在醫用領域(yu)應用廣泛。
主要品種
硅(gui)橡(xiang)(xiang)膠分類(lei)的(de)方法很(hen)多(duo),通常按(an)固化(hua)前的(de)形態分為固體(ti)硅(gui)橡(xiang)(xiang)膠和(he)液體(ti)硅(gui)橡(xiang)(xiang)膠;按(an)硫化(hua)溫(wen)(wen)度分為室溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠,高溫(wen)(wen)硫化(hua)硅(gui)橡(xiang)(xiang)膠;按(an)所用(yong)單(dan)體(ti)的(de)不同,可分為甲(jia)基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠,甲(jia)基(ji)(ji)苯(ben)基(ji)(ji)乙烯基(ji)(ji)硅(gui)橡(xiang)(xiang)膠、氟硅(gui),腈(jing)硅(gui)橡(xiang)(xiang)膠等(deng);按(an)性能和(he)用(yong)途的(de)不同又可分為通用(yong)型(xing)、超耐(nai)低溫(wen)(wen)型(xing)、超耐(nai)高溫(wen)(wen)型(xing)、高強力(li)型(xing)、耐(nai)油型(xing)、醫用(yong)型(xing)等(deng)等(deng)。
發展史
硅(gui)橡(xiang)膠(jiao)早期是由美(mei)國(guo)(guo)以三氯化(hua)鐵為催(cui)化(hua)劑合成的(de)(de)。1945年(nian),硅(gui)橡(xiang)膠(jiao)產(chan)(chan)品問世(shi)。1948年(nian),采用高比表面積(ji)的(de)(de)氣相法白(bai)炭黑補強的(de)(de)硅(gui)橡(xiang)膠(jiao)研制(zhi)成功(gong),使硅(gui)橡(xiang)膠(jiao)的(de)(de)性能(neng)躍升到實用階段,奠定(ding)了現代硅(gui)橡(xiang)膠(jiao)生(sheng)產(chan)(chan)技術(shu)的(de)(de)基(ji)礎。從二(er)甲基(ji)二(er)氯硅(gui)烷合成開(kai)始生(sheng)產(chan)(chan)硅(gui)橡(xiang)膠(jiao)的(de)(de)國(guo)(guo)家有美(mei)國(guo)(guo)。俄羅斯、德國(guo)(guo)、日(ri)本、韓國(guo)(guo)和中(zhong)國(guo)(guo)等。中(zhong)國(guo)(guo)硅(gui)橡(xiang)膠(jiao)的(de)(de)工(gong)業化(hua)研究始于1957年(nian),多家研究所和企業陸續開(kai)發出各種硅(gui)橡(xiang)膠(jiao)。到2003年(nian)底,中(zhong)國(guo)(guo)硅(gui)橡(xiang)膠(jiao)生(sheng)產(chan)(chan)能(neng)力為135千噸,其中(zhong)高溫(wen)膠(jiao)100千噸。
高溫硫化硅橡膠
高(gao)溫(wen)硫(liu)化(hua)(hua)(hua)(hua)硅(gui)橡膠(jiao)(jiao)是指聚硅(gui)氧(yang)烷變成(cheng)(cheng)彈性體的過程(cheng)是經過高(gao)溫(wen)(110-170℃)硫(liu)化(hua)(hua)(hua)(hua)成(cheng)(cheng)型(xing)的。它主要(yao)以高(gao)分子(zi)量的聚甲基乙烯基硅(gui)氧(yang)烷為生膠(jiao)(jiao),混入補強(qiang)填料(liao)、硫(liu)化(hua)(hua)(hua)(hua)劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓下硫(liu)化(hua)(hua)(hua)(hua)成(cheng)(cheng)彈性體。硅(gui)橡膠(jiao)(jiao)的補強(qiang)主要(yao)是各(ge)種(zhong)類(lei)型(xing)的白炭(tan)黑,可使硫(liu)化(hua)(hua)(hua)(hua)膠(jiao)(jiao)的強(qiang)度增加(jia)(jia)數十倍。有時為了降低成(cheng)(cheng)本(ben)或(huo)改善膠(jiao)(jiao)料(liao)性能及賦予硫(liu)化(hua)(hua)(hua)(hua)膠(jiao)(jiao)各(ge)種(zhong)特殊(shu)的性能,也加(jia)(jia)入相應(ying)的各(ge)種(zhong)添(tian)加(jia)(jia)劑(ji)。硫(liu)化(hua)(hua)(hua)(hua)劑(ji)是各(ge)種(zhong)有機過氧(yang)化(hua)(hua)(hua)(hua)物或(huo)加(jia)(jia)成(cheng)(cheng)反應(ying)催化(hua)(hua)(hua)(hua)劑(ji)。
加工(gong)成型方法(fa)如(ru)圖(tu)所示。一次硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是進(jin)行高分子鏈的(de)(de)(de)交(jiao)聯反(fan)應;二次硫(liu)化(hua)的(de)(de)(de)目的(de)(de)(de)是進(jin)行補充交(jiao)聯、驅除硫(liu)化(hua)劑分解產物和其(qi)他揮發性化(hua)合(he)物以穩定硫(liu)化(hua)膠的(de)(de)(de)各(ge)項性能。常(chang)用的(de)(de)(de)設(she)備有開放式煉(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)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)顯著的(de)特征是高(gao)溫(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing),雖然常溫(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)強(qiang)度(du)僅是天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)或某些合成橡(xiang)(xiang)膠(jiao)(jiao)的(de)一(yi)半,但(dan)在(zai)(zai)200℃以上的(de)高(gao)溫(wen)(wen)(wen)環境下,硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)仍能(neng)(neng)(neng)(neng)(neng)(neng)保(bao)持一(yi)定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度(du),且力學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)無(wu)明(ming)顯變(bian)化。(2)低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)的(de)玻璃化溫(wen)(wen)(wen)度(du)一(yi)般為-70~-50℃,特殊配(pei)方可達(da)-100℃,表(biao)明(ming)其低(di)溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優異(yi)。這對航空(kong)、宇航工業(ye)的(de)意義(yi)重大(da)。(3)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭(chou)氧(yang)及紫外線等十分穩(wen)定,在(zai)(zai)不加(jia)任何添加(jia)劑(ji)的(de)情況下,就具(ju)(ju)(ju)有優良(liang)的(de)耐(nai)(nai)候性(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)(ju)有優異(yi)的(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng),耐(nai)(nai)電暈性(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電弧性(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)常溫(wen)(wen)(wen)下的(de)物(wu)理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)比通用橡(xiang)(xiang)膠(jiao)(jiao)差,但(dan)在(zai)(zai)150℃的(de)高(gao)溫(wen)(wen)(wen)和(he)-50℃的(de)低(di)溫(wen)(wen)(wen)下,其物(wu)理機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)優于通用橡(xiang)(xiang)膠(jiao)(jiao)。(6)耐(nai)(nai)油(you)及化學試(shi)劑(ji)性(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)具(ju)(ju)(ju)有中等的(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)對空(kong)氣(qi)、氮、氧(yang)、二氧(yang)化碳等氣(qi)體(ti)的(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)比天(tian)然橡(xiang)(xiang)膠(jiao)(jiao)高(gao)出30-50倍。(8)生理惰性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)無(wu)毒,無(wu)味,無(wu)嗅(xiu),與人體(ti)組(zu)織不粘連,具(ju)(ju)(ju)有抗凝血作用,對肌(ji)體(ti)組(zu)織的(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)非常少。特別適合作為醫用材(cai)料。
硅橡膠的用量
據中國(guo)(guo)汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業協會統計(ji),2012年,汽(qi)(qi)(qi)車(che)(che)產(chan)銷分別(bie)達到1927.18萬(wan)輛和(he)1930.64萬(wan)輛,同(tong)比分別(bie)增長4.63%和(he)4.33%,汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業硅(gui)橡膠的(de)(de)(de)用(yong)量(liang)約達2.0萬(wan)t。根據觀研(yan)天下的(de)(de)(de)新研(yan)究,增加有(you)機(ji)硅(gui)材(cai)料在汽(qi)(qi)(qi)車(che)(che)零部件方面的(de)(de)(de)用(yong)量(liang),可以(yi)(yi)大(da)(da)幅度提(ti)高汽(qi)(qi)(qi)車(che)(che)的(de)(de)(de)安全性(xing)能,因(yin)此,汽(qi)(qi)(qi)車(che)(che)產(chan)量(liang)和(he)單車(che)(che)用(yong)量(liang)水(shui)平的(de)(de)(de)提(ti)高都將推動(dong)汽(qi)(qi)(qi)車(che)(che)工(gong)(gong)業對硅(gui)橡膠需求(qiu)的(de)(de)(de)增加。國(guo)(guo)家鼓勵自主(zhu)品(pin)(pin)牌(pai)的(de)(de)(de)汽(qi)(qi)(qi)車(che)(che)發(fa)展(zhan),關鍵汽(qi)(qi)(qi)車(che)(che)零部件實(shi)現自主(zhu)化(hua)(hua),《2012年度黨政機(ji)關公(gong)務用(yong)車(che)(che)選用(yong)車(che)(che)型目錄(lu)(征(zheng)求(qiu)意見(jian)稿)》為(wei)自主(zhu)品(pin)(pin)牌(pai)擴大(da)(da)在政府采(cai)購(gou)(gou)的(de)(de)(de)市場份額,為(wei)改變目前(qian)國(guo)(guo)內(nei)政府采(cai)購(gou)(gou)以(yi)(yi)合資品(pin)(pin)牌(pai)產(chan)品(pin)(pin)為(wei)主(zhu)的(de)(de)(de)局面提(ti)供了保障。促進自主(zhu)品(pin)(pin)牌(pai)發(fa)展(zhan),國(guo)(guo)產(chan)汽(qi)(qi)(qi)車(che)(che)業的(de)(de)(de)繁榮將為(wei)汽(qi)(qi)(qi)車(che)(che)膠的(de)(de)(de)應用(yong)提(ti)供有(you)力保障。預測(ce)未來3年,我(wo)國(guo)(guo)室溫硫(liu)化(hua)(hua)硅(gui)橡膠在汽(qi)(qi)(qi)車(che)(che)行業將以(yi)(yi)年均20%增長。
此外,硅(gui)(gui)橡膠(jiao)(jiao)是重(zhong)要的非石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao),約占非石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao)消(xiao)費量(liang)的98%。但因為石(shi)(shi)油(you)(you)價(jia)格的大幅(fu)上漲,同時我國在硅(gui)(gui)橡膠(jiao)(jiao)的關鍵(jian)原料有機(ji)(ji)硅(gui)(gui)單(dan)體的生(sheng)產(chan)技(ji)(ji)術(shu)方(fang)面取得突破,有機(ji)(ji)硅(gui)(gui)單(dan)體的生(sheng)產(chan)技(ji)(ji)術(shu)在2005年前被幾家(jia)跨(kua)國公司壟斷(duan),但目(mu)前我國已發展(zhan)成(cheng)為全球有機(ji)(ji)硅(gui)(gui)單(dan)體第1大國,這(zhe)2個方(fang)面原因使硅(gui)(gui)橡膠(jiao)(jiao)的價(jia)格從2011年起開始(shi)低(di)于(yu)石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao),僅(jin)約為大宗石(shi)(shi)油(you)(you)基橡膠(jiao)(jiao)的80%~90%,成(cheng)為廉價(jia)的合(he)成(cheng)橡膠(jiao)(jiao),并開始(shi)大規模替(ti)代石(shi)(shi)油(you)(you)基合(he)成(cheng)橡膠(jiao)(jiao)。這(zhe)將(jiang)極大拓展(zhan)有機(ji)(ji)硅(gui)(gui)產(chan)業的市場(chang)空間,同時將(jiang)帶動硅(gui)(gui)油(you)(you)、硅(gui)(gui)烷(wan)偶聯劑和硅(gui)(gui)樹(shu)脂等其他(ta)有機(ji)(ji)硅(gui)(gui)產(chan)品的消(xiao)費。