
硅橡膠是指主鏈由硅(gui)和(he)氧原子(zi)交替(ti)構成(cheng),硅(gui)原子(zi)上通常連(lian)有(you)兩個有(you)機(ji)基(ji)團的(de)(de)橡(xiang)(xiang)膠(jiao)。普通的(de)(de)硅(gui)橡(xiang)(xiang)膠(jiao)主要由含甲基(ji)和(he)少量乙(yi)烯基(ji)的(de)(de)硅(gui)氧鏈節組成(cheng)。苯(ben)基(ji)的(de)(de)引(yin)入可(ke)提(ti)高硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)(nai)(nai)(nai)高、低溫(wen)性(xing)能(neng)(neng),三氟(fu)丙(bing)基(ji)及(ji)氰基(ji)的(de)(de)引(yin)入則可(ke)提(ti)高硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)(nai)(nai)(nai)溫(wen)及(ji)耐(nai)(nai)(nai)(nai)油性(xing)能(neng)(neng)。硅(gui)橡(xiang)(xiang)膠(jiao)耐(nai)(nai)(nai)(nai)低溫(wen)性(xing)能(neng)(neng)良好,一(yi)般(ban)在-55℃下仍能(neng)(neng)工作(zuo)。引(yin)入苯(ben)基(ji)后,可(ke)達-73℃。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)耐(nai)(nai)(nai)(nai)熱性(xing)能(neng)(neng)也很突(tu)出,在180℃下可(ke)長期工作(zuo),稍高于200℃也能(neng)(neng)承受數周(zhou)或更長時間仍有(you)彈性(xing),瞬時可(ke)耐(nai)(nai)(nai)(nai)300℃以上的(de)(de)高溫(wen)。硅(gui)橡(xiang)(xiang)膠(jiao)的(de)(de)透氣(qi)性(xing)好,氧氣(qi)透過率(lv)在合(he)成(cheng)聚合(he)物中是較高的(de)(de)。此外(wai),硅(gui)橡(xiang)(xiang)膠(jiao)還(huan)具有(you)生理惰性(xing)、不(bu)會導(dao)致(zhi)凝血的(de)(de)突(tu)出特性(xing),因此在醫用領域應用廣泛(fan)。
主要品種
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)分(fen)(fen)類的(de)方法很多,通(tong)常按(an)固化前的(de)形態分(fen)(fen)為固體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)和液體硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)硫化溫(wen)度分(fen)(fen)為室溫(wen)硫化硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),高(gao)溫(wen)硫化硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao);按(an)所用單體的(de)不同(tong),可分(fen)(fen)為甲(jia)基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao),甲(jia)基(ji)苯基(ji)乙(yi)烯基(ji)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)、氟硅(gui)(gui),腈硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)等(deng);按(an)性能和用途的(de)不同(tong)又(you)可分(fen)(fen)為通(tong)用型(xing)、超(chao)耐低溫(wen)型(xing)、超(chao)耐高(gao)溫(wen)型(xing)、高(gao)強力型(xing)、耐油型(xing)、醫用型(xing)等(deng)等(deng)。
發展史
硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)早期(qi)是由美(mei)(mei)國以三氯化(hua)(hua)鐵為催化(hua)(hua)劑合成(cheng)的(de)(de)(de)。1945年(nian),硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)產(chan)品(pin)問世。1948年(nian),采(cai)用高比表面積的(de)(de)(de)氣相法(fa)白炭(tan)黑補強的(de)(de)(de)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)研制(zhi)成(cheng)功,使硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)性能(neng)躍升到(dao)實(shi)用階段,奠定了現(xian)代硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)技術的(de)(de)(de)基礎。從二甲基二氯硅(gui)(gui)(gui)(gui)烷(wan)合成(cheng)開始(shi)生產(chan)硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)國家(jia)有美(mei)(mei)國。俄(e)羅斯、德(de)國、日(ri)本、韓國和中(zhong)國等。中(zhong)國硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)工業(ye)化(hua)(hua)研究(jiu)始(shi)于1957年(nian),多家(jia)研究(jiu)所(suo)和企業(ye)陸續開發出各(ge)種硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)。到(dao)2003年(nian)底,中(zhong)國硅(gui)(gui)(gui)(gui)橡(xiang)膠(jiao)(jiao)(jiao)生產(chan)能(neng)力為135千噸(dun),其中(zhong)高溫膠(jiao)(jiao)(jiao)100千噸(dun)。
高溫硫化硅橡膠
高溫硫化(hua)(hua)(hua)硅(gui)橡膠(jiao)是指聚硅(gui)氧(yang)烷變成彈性(xing)(xing)體的過程(cheng)是經過高溫(110-170℃)硫化(hua)(hua)(hua)成型的。它(ta)主要(yao)以高分子量的聚甲(jia)基乙(yi)烯基硅(gui)氧(yang)烷為生(sheng)膠(jiao),混(hun)入(ru)補強(qiang)填(tian)料、硫化(hua)(hua)(hua)劑(ji)等(deng),在加(jia)熱加(jia)壓下硫化(hua)(hua)(hua)成彈性(xing)(xing)體。硅(gui)橡膠(jiao)的補強(qiang)主要(yao)是各(ge)種(zhong)(zhong)類型的白(bai)炭黑,可使(shi)硫化(hua)(hua)(hua)膠(jiao)的強(qiang)度增加(jia)數十倍(bei)。有時(shi)為了降(jiang)低(di)成本或改善膠(jiao)料性(xing)(xing)能及(ji)賦予硫化(hua)(hua)(hua)膠(jiao)各(ge)種(zhong)(zhong)特殊的性(xing)(xing)能,也加(jia)入(ru)相應的各(ge)種(zhong)(zhong)添加(jia)劑(ji)。硫化(hua)(hua)(hua)劑(ji)是各(ge)種(zhong)(zhong)有機過氧(yang)化(hua)(hua)(hua)物或加(jia)成反應催化(hua)(hua)(hua)劑(ji)。
加工(gong)成型方法(fa)如圖所示(shi)。一(yi)次硫(liu)(liu)化(hua)的目(mu)的是進(jin)(jin)行高(gao)分子鏈的交(jiao)聯反應;二次硫(liu)(liu)化(hua)的目(mu)的是進(jin)(jin)行補充交(jiao)聯、驅除硫(liu)(liu)化(hua)劑分解產物(wu)和(he)其(qi)他揮(hui)發性化(hua)合物(wu)以穩定(ding)硫(liu)(liu)化(hua)膠的各(ge)項(xiang)性能。常(chang)用的設備(bei)有(you)開放式煉膠機(ji)、捏合機(ji)及真空密煉機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)顯著的(de)特征是高溫(wen)(wen)(wen)(wen)穩(wen)定性(xing)(xing)(xing)(xing)(xing)(xing)(xing),雖(sui)然常溫(wen)(wen)(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)強度(du)僅(jin)是天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)或某些合成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)一半,但(dan)(dan)在200℃以上的(de)高溫(wen)(wen)(wen)(wen)環境(jing)下,硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)仍(reng)能(neng)(neng)(neng)(neng)(neng)保持一定的(de)柔韌性(xing)(xing)(xing)(xing)(xing)(xing)(xing)、回(hui)彈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和表(biao)面硬度(du),且力(li)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)無(wu)明顯變(bian)化(hua)。(2)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)的(de)玻(bo)璃(li)化(hua)溫(wen)(wen)(wen)(wen)度(du)一般為-70~-50℃,特殊配方可(ke)達(da)-100℃,表(biao)明其(qi)低溫(wen)(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優異(yi)。這對航空、宇(yu)航工業的(de)意義重(zhong)大。(3)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)中Si-O-Si鍵對氧、臭氧及(ji)紫外線等十分穩(wen)定,在不加(jia)任(ren)何添加(jia)劑(ji)的(de)情(qing)況下,就具有(you)(you)(you)優良的(de)耐(nai)候性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。(4)電氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)(you)(you)優異(yi)的(de)絕緣性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng),耐(nai)電暈性(xing)(xing)(xing)(xing)(xing)(xing)(xing)和耐(nai)電弧(hu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)也非常好(hao)。(5)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)常溫(wen)(wen)(wen)(wen)下的(de)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)比通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)差,但(dan)(dan)在150℃的(de)高溫(wen)(wen)(wen)(wen)和-50℃的(de)低溫(wen)(wen)(wen)(wen)下,其(qi)物(wu)(wu)理(li)機(ji)械(xie)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)優于通用(yong)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)。(6)耐(nai)油(you)及(ji)化(hua)學試劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。普(pu)通硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)具有(you)(you)(you)中等的(de)耐(nai)油(you)、耐(nai)溶劑(ji)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。(7)氣(qi)體(ti)透過性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)(neng)(neng)。室溫(wen)(wen)(wen)(wen)下硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)對空氣(qi)、氮、氧、二氧化(hua)碳(tan)等氣(qi)體(ti)的(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)比天然橡(xiang)膠(jiao)(jiao)(jiao)(jiao)高出(chu)30-50倍(bei)。(8)生理(li)惰性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。硅橡(xiang)膠(jiao)(jiao)(jiao)(jiao)無(wu)毒(du),無(wu)味,無(wu)嗅,與人(ren)體(ti)組織不粘連(lian),具有(you)(you)(you)抗凝(ning)血作用(yong),對肌體(ti)組織的(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)(xing)(xing)非常少(shao)。特別(bie)適合作為醫用(yong)材料。
硅橡膠的用量
據(ju)中國(guo)汽(qi)(qi)車(che)工(gong)(gong)業協會統計,2012年,汽(qi)(qi)車(che)產(chan)銷分別(bie)達(da)到(dao)1927.18萬(wan)輛和1930.64萬(wan)輛,同(tong)比分別(bie)增(zeng)長4.63%和4.33%,汽(qi)(qi)車(che)工(gong)(gong)業硅(gui)(gui)橡膠的(de)(de)(de)用(yong)量約達(da)2.0萬(wan)t。根據(ju)觀研天下的(de)(de)(de)新研究,增(zeng)加有(you)機(ji)硅(gui)(gui)材料在汽(qi)(qi)車(che)零部件方(fang)面的(de)(de)(de)用(yong)量,可以(yi)大(da)幅度(du)提(ti)高汽(qi)(qi)車(che)的(de)(de)(de)安(an)全性能(neng),因此,汽(qi)(qi)車(che)產(chan)量和單(dan)車(che)用(yong)量水平(ping)的(de)(de)(de)提(ti)高都將(jiang)推動汽(qi)(qi)車(che)工(gong)(gong)業對硅(gui)(gui)橡膠需求的(de)(de)(de)增(zeng)加。國(guo)家鼓勵自(zi)(zi)主(zhu)(zhu)(zhu)品牌(pai)(pai)的(de)(de)(de)汽(qi)(qi)車(che)發展,關鍵汽(qi)(qi)車(che)零部件實現自(zi)(zi)主(zhu)(zhu)(zhu)化,《2012年度(du)黨政機(ji)關公(gong)務用(yong)車(che)選用(yong)車(che)型(xing)目錄(征(zheng)求意(yi)見(jian)稿(gao))》為(wei)(wei)自(zi)(zi)主(zhu)(zhu)(zhu)品牌(pai)(pai)擴大(da)在政府采購的(de)(de)(de)市場份(fen)額,為(wei)(wei)改變目前國(guo)內政府采購以(yi)合(he)資品牌(pai)(pai)產(chan)品為(wei)(wei)主(zhu)(zhu)(zhu)的(de)(de)(de)局面提(ti)供(gong)了保障。促進自(zi)(zi)主(zhu)(zhu)(zhu)品牌(pai)(pai)發展,國(guo)產(chan)汽(qi)(qi)車(che)業的(de)(de)(de)繁榮將(jiang)為(wei)(wei)汽(qi)(qi)車(che)膠的(de)(de)(de)應用(yong)提(ti)供(gong)有(you)力保障。預測未來3年,我(wo)國(guo)室溫硫化硅(gui)(gui)橡膠在汽(qi)(qi)車(che)行業將(jiang)以(yi)年均(jun)20%增(zeng)長。
此外,硅(gui)(gui)橡(xiang)膠(jiao)(jiao)是重要的(de)非石(shi)油基(ji)合成(cheng)橡(xiang)膠(jiao)(jiao),約(yue)占非石(shi)油基(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)消費(fei)量的(de)98%。但(dan)因為石(shi)油價(jia)格的(de)大(da)(da)幅上(shang)漲,同時我國(guo)在硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)關鍵原料有(you)(you)機硅(gui)(gui)單(dan)體(ti)的(de)生(sheng)產(chan)(chan)技術方面(mian)取(qu)得突(tu)破,有(you)(you)機硅(gui)(gui)單(dan)體(ti)的(de)生(sheng)產(chan)(chan)技術在2005年(nian)前(qian)被幾家跨(kua)國(guo)公司壟斷,但(dan)目前(qian)我國(guo)已(yi)發展(zhan)成(cheng)為全球有(you)(you)機硅(gui)(gui)單(dan)體(ti)第1大(da)(da)國(guo),這2個方面(mian)原因使硅(gui)(gui)橡(xiang)膠(jiao)(jiao)的(de)價(jia)格從2011年(nian)起開始低于石(shi)油基(ji)合成(cheng)橡(xiang)膠(jiao)(jiao),僅約(yue)為大(da)(da)宗石(shi)油基(ji)橡(xiang)膠(jiao)(jiao)的(de)80%~90%,成(cheng)為廉價(jia)的(de)合成(cheng)橡(xiang)膠(jiao)(jiao),并開始大(da)(da)規(gui)模替代(dai)石(shi)油基(ji)合成(cheng)橡(xiang)膠(jiao)(jiao)。這將(jiang)極大(da)(da)拓(tuo)展(zhan)有(you)(you)機硅(gui)(gui)產(chan)(chan)業的(de)市場空間(jian),同時將(jiang)帶動硅(gui)(gui)油、硅(gui)(gui)烷偶聯劑和硅(gui)(gui)樹脂(zhi)等其(qi)他有(you)(you)機硅(gui)(gui)產(chan)(chan)品的(de)消費(fei)。