硅橡膠是(shi)指主鏈由(you)硅(gui)(gui)和氧(yang)(yang)原子交替構(gou)成,硅(gui)(gui)原子上(shang)通常連(lian)有(you)(you)兩個有(you)(you)機基(ji)(ji)團的(de)(de)橡(xiang)(xiang)(xiang)膠。普(pu)通的(de)(de)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠主要由(you)含甲(jia)基(ji)(ji)和少量(liang)乙烯基(ji)(ji)的(de)(de)硅(gui)(gui)氧(yang)(yang)鏈節組(zu)成。苯基(ji)(ji)的(de)(de)引入可(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)(nai)高、低溫性(xing)(xing)(xing)能(neng),三(san)氟丙基(ji)(ji)及氰基(ji)(ji)的(de)(de)引入則可(ke)(ke)提高硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)(nai)溫及耐(nai)(nai)(nai)油性(xing)(xing)(xing)能(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠耐(nai)(nai)(nai)低溫性(xing)(xing)(xing)能(neng)良好(hao),一般在(zai)-55℃下仍(reng)能(neng)工作。引入苯基(ji)(ji)后,可(ke)(ke)達-73℃。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)耐(nai)(nai)(nai)熱性(xing)(xing)(xing)能(neng)也很突出,在(zai)180℃下可(ke)(ke)長期(qi)工作,稍高于200℃也能(neng)承受數周或更長時間仍(reng)有(you)(you)彈(dan)性(xing)(xing)(xing),瞬時可(ke)(ke)耐(nai)(nai)(nai)300℃以(yi)上(shang)的(de)(de)高溫。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠的(de)(de)透氣性(xing)(xing)(xing)好(hao),氧(yang)(yang)氣透過率(lv)在(zai)合(he)成聚合(he)物中是(shi)較高的(de)(de)。此(ci)外,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠還具(ju)有(you)(you)生理惰性(xing)(xing)(xing)、不會(hui)導(dao)致凝血的(de)(de)突出特(te)性(xing)(xing)(xing),因(yin)此(ci)在(zai)醫用領(ling)域應用廣泛。
主要品種
硅(gui)橡(xiang)膠(jiao)分(fen)類的(de)方法很(hen)多,通常按(an)(an)固化前的(de)形態分(fen)為(wei)(wei)(wei)固體(ti)硅(gui)橡(xiang)膠(jiao)和液(ye)體(ti)硅(gui)橡(xiang)膠(jiao);按(an)(an)硫(liu)化溫(wen)度分(fen)為(wei)(wei)(wei)室溫(wen)硫(liu)化硅(gui)橡(xiang)膠(jiao),高溫(wen)硫(liu)化硅(gui)橡(xiang)膠(jiao);按(an)(an)所用(yong)單體(ti)的(de)不(bu)(bu)同(tong),可分(fen)為(wei)(wei)(wei)甲(jia)基(ji)乙(yi)烯(xi)基(ji)硅(gui)橡(xiang)膠(jiao),甲(jia)基(ji)苯基(ji)乙(yi)烯(xi)基(ji)硅(gui)橡(xiang)膠(jiao)、氟硅(gui),腈(jing)硅(gui)橡(xiang)膠(jiao)等(deng)(deng);按(an)(an)性能和用(yong)途的(de)不(bu)(bu)同(tong)又可分(fen)為(wei)(wei)(wei)通用(yong)型、超耐低溫(wen)型、超耐高溫(wen)型、高強力型、耐油型、醫用(yong)型等(deng)(deng)等(deng)(deng)。
發展史
硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)早期是由美國(guo)以三氯化(hua)鐵(tie)為催(cui)化(hua)劑合成(cheng)的(de)(de)。1945年(nian),硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)產品(pin)問世。1948年(nian),采用(yong)(yong)高比表面積的(de)(de)氣相(xiang)法白炭(tan)黑補強的(de)(de)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)研制(zhi)成(cheng)功,使硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)性能躍(yue)升到實用(yong)(yong)階段(duan),奠定了現代(dai)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)生(sheng)產技術的(de)(de)基礎。從二甲基二氯硅(gui)(gui)烷(wan)合成(cheng)開(kai)始生(sheng)產硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)國(guo)家有美國(guo)。俄羅斯(si)、德(de)國(guo)、日本、韓國(guo)和中國(guo)等。中國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)(de)工業化(hua)研究(jiu)(jiu)始于(yu)1957年(nian),多家研究(jiu)(jiu)所(suo)和企(qi)業陸續開(kai)發(fa)出各種硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。到2003年(nian)底,中國(guo)硅(gui)(gui)橡(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)生(sheng)產能力(li)為135千噸,其中高溫(wen)膠(jiao)(jiao)(jiao)(jiao)(jiao)100千噸。
高溫硫化硅橡膠
高溫硫(liu)化硅(gui)橡膠(jiao)是(shi)(shi)指聚(ju)硅(gui)氧(yang)烷(wan)變成(cheng)(cheng)(cheng)彈性(xing)體的(de)(de)過(guo)(guo)程(cheng)是(shi)(shi)經過(guo)(guo)高溫(110-170℃)硫(liu)化成(cheng)(cheng)(cheng)型的(de)(de)。它(ta)主要以高分(fen)子(zi)量的(de)(de)聚(ju)甲(jia)基(ji)(ji)乙(yi)烯(xi)基(ji)(ji)硅(gui)氧(yang)烷(wan)為生膠(jiao),混(hun)入補強填料、硫(liu)化劑(ji)等,在加(jia)(jia)熱加(jia)(jia)壓(ya)下硫(liu)化成(cheng)(cheng)(cheng)彈性(xing)體。硅(gui)橡膠(jiao)的(de)(de)補強主要是(shi)(shi)各種類(lei)型的(de)(de)白炭黑,可使硫(liu)化膠(jiao)的(de)(de)強度增加(jia)(jia)數十倍。有時為了降低成(cheng)(cheng)(cheng)本或改善(shan)膠(jiao)料性(xing)能及賦予硫(liu)化膠(jiao)各種特殊的(de)(de)性(xing)能,也(ye)加(jia)(jia)入相應的(de)(de)各種添(tian)加(jia)(jia)劑(ji)。硫(liu)化劑(ji)是(shi)(shi)各種有機過(guo)(guo)氧(yang)化物或加(jia)(jia)成(cheng)(cheng)(cheng)反應催化劑(ji)。
加工成型方法(fa)如圖所示。一次硫化的目的是(shi)進(jin)行高分(fen)子(zi)鏈的交聯(lian)反(fan)應;二次硫化的目的是(shi)進(jin)行補充交聯(lian)、驅除硫化劑(ji)分(fen)解產物(wu)(wu)和其他揮發(fa)性化合物(wu)(wu)以穩定硫化膠的各項性能。常(chang)用的設(she)備有開放式煉膠機(ji)、捏(nie)合機(ji)及(ji)真空(kong)密煉機(ji)。
主要性能
(1)高溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)顯著的(de)(de)(de)(de)特(te)征(zheng)是(shi)高溫(wen)(wen)(wen)穩定性(xing)(xing)(xing)(xing)(xing),雖然常(chang)溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)強度僅是(shi)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)或某些合(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)一(yi)半,但(dan)在200℃以上的(de)(de)(de)(de)高溫(wen)(wen)(wen)環境下,硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)仍能(neng)(neng)(neng)保(bao)持一(yi)定的(de)(de)(de)(de)柔韌(ren)性(xing)(xing)(xing)(xing)(xing)、回彈(dan)性(xing)(xing)(xing)(xing)(xing)和(he)表(biao)面硬度,且力(li)學性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)無明(ming)顯變化(hua)。(2)低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)的(de)(de)(de)(de)玻璃化(hua)溫(wen)(wen)(wen)度一(yi)般(ban)為(wei)-70~-50℃,特(te)殊配方可達-100℃,表(biao)明(ming)其低溫(wen)(wen)(wen)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)(you)異。這對航空、宇航工(gong)業的(de)(de)(de)(de)意義重大。(3)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)中Si-O-Si鍵對氧(yang)、臭氧(yang)及(ji)(ji)紫外線等十(shi)分(fen)穩定,在不加任何添加劑的(de)(de)(de)(de)情況下,就具有優(you)(you)(you)良的(de)(de)(de)(de)耐(nai)(nai)候(hou)性(xing)(xing)(xing)(xing)(xing)。(4)電(dian)氣(qi)性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具有優(you)(you)(you)異的(de)(de)(de)(de)絕緣性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng),耐(nai)(nai)電(dian)暈性(xing)(xing)(xing)(xing)(xing)和(he)耐(nai)(nai)電(dian)弧(hu)性(xing)(xing)(xing)(xing)(xing)也(ye)非(fei)(fei)常(chang)好。(5)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)常(chang)溫(wen)(wen)(wen)下的(de)(de)(de)(de)物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)比(bi)通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)差,但(dan)在150℃的(de)(de)(de)(de)高溫(wen)(wen)(wen)和(he)-50℃的(de)(de)(de)(de)低溫(wen)(wen)(wen)下,其物(wu)理(li)機(ji)械性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)優(you)(you)(you)于通用(yong)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)。(6)耐(nai)(nai)油(you)及(ji)(ji)化(hua)學試劑性(xing)(xing)(xing)(xing)(xing)。普通硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)具有中等的(de)(de)(de)(de)耐(nai)(nai)油(you)、耐(nai)(nai)溶劑性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。(7)氣(qi)體透過性(xing)(xing)(xing)(xing)(xing)能(neng)(neng)(neng)。室溫(wen)(wen)(wen)下硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)對空氣(qi)、氮(dan)、氧(yang)、二氧(yang)化(hua)碳等氣(qi)體的(de)(de)(de)(de)透氣(qi)性(xing)(xing)(xing)(xing)(xing)比(bi)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)高出30-50倍。(8)生理(li)惰(duo)性(xing)(xing)(xing)(xing)(xing)。硅(gui)(gui)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)無毒,無味,無嗅(xiu),與(yu)人(ren)體組織不粘連(lian),具有抗(kang)凝血作用(yong),對肌體組織的(de)(de)(de)(de)反(fan)應性(xing)(xing)(xing)(xing)(xing)非(fei)(fei)常(chang)少。特(te)別適合(he)作為(wei)醫(yi)用(yong)材(cai)料。
硅橡膠的用量
據中國汽(qi)(qi)(qi)車(che)工(gong)業協會統(tong)計,2012年(nian)(nian),汽(qi)(qi)(qi)車(che)產銷(xiao)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)(qi)車(che)工(gong)業硅(gui)橡(xiang)(xiang)膠(jiao)的用(yong)(yong)(yong)量(liang)約達(da)2.0萬(wan)t。根(gen)據觀研(yan)天下的新研(yan)究,增(zeng)加有機硅(gui)材料在(zai)汽(qi)(qi)(qi)車(che)零(ling)部(bu)件方面的用(yong)(yong)(yong)量(liang),可以大(da)幅度提(ti)高汽(qi)(qi)(qi)車(che)的安全性(xing)能(neng),因(yin)此(ci),汽(qi)(qi)(qi)車(che)產量(liang)和單車(che)用(yong)(yong)(yong)量(liang)水平的提(ti)高都將(jiang)(jiang)推(tui)動汽(qi)(qi)(qi)車(che)工(gong)業對硅(gui)橡(xiang)(xiang)膠(jiao)需求的增(zeng)加。國家鼓勵自(zi)主品(pin)牌(pai)的汽(qi)(qi)(qi)車(che)發展,關鍵汽(qi)(qi)(qi)車(che)零(ling)部(bu)件實(shi)現自(zi)主化,《2012年(nian)(nian)度黨政(zheng)機關公務用(yong)(yong)(yong)車(che)選用(yong)(yong)(yong)車(che)型目錄(征求意(yi)見稿)》為自(zi)主品(pin)牌(pai)擴大(da)在(zai)政(zheng)府采購(gou)的市(shi)場份額,為改變(bian)目前國內政(zheng)府采購(gou)以合資品(pin)牌(pai)產品(pin)為主的局面提(ti)供了保障(zhang)。促(cu)進自(zi)主品(pin)牌(pai)發展,國產汽(qi)(qi)(qi)車(che)業的繁(fan)榮將(jiang)(jiang)為汽(qi)(qi)(qi)車(che)膠(jiao)的應用(yong)(yong)(yong)提(ti)供有力保障(zhang)。預測未來3年(nian)(nian),我國室溫(wen)硫化硅(gui)橡(xiang)(xiang)膠(jiao)在(zai)汽(qi)(qi)(qi)車(che)行業將(jiang)(jiang)以年(nian)(nian)均20%增(zeng)長。
此外,硅(gui)(gui)(gui)橡膠(jiao)是重(zhong)要(yao)的(de)(de)(de)非石(shi)(shi)油(you)基(ji)(ji)合(he)成橡膠(jiao),約占非石(shi)(shi)油(you)基(ji)(ji)合(he)成橡膠(jiao)消費量的(de)(de)(de)98%。但因為石(shi)(shi)油(you)價(jia)格的(de)(de)(de)大(da)(da)幅上漲(zhang),同時(shi)我國(guo)在硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)(de)關鍵原(yuan)料有機(ji)硅(gui)(gui)(gui)單體(ti)(ti)的(de)(de)(de)生(sheng)產(chan)(chan)技(ji)術方面(mian)取得突破,有機(ji)硅(gui)(gui)(gui)單體(ti)(ti)的(de)(de)(de)生(sheng)產(chan)(chan)技(ji)術在2005年前被幾家跨國(guo)公司(si)壟(long)斷(duan),但目(mu)前我國(guo)已發展(zhan)成為全球有機(ji)硅(gui)(gui)(gui)單體(ti)(ti)第1大(da)(da)國(guo),這2個方面(mian)原(yuan)因使硅(gui)(gui)(gui)橡膠(jiao)的(de)(de)(de)價(jia)格從2011年起開(kai)始低于石(shi)(shi)油(you)基(ji)(ji)合(he)成橡膠(jiao),僅約為大(da)(da)宗石(shi)(shi)油(you)基(ji)(ji)橡膠(jiao)的(de)(de)(de)80%~90%,成為廉價(jia)的(de)(de)(de)合(he)成橡膠(jiao),并開(kai)始大(da)(da)規模替代(dai)石(shi)(shi)油(you)基(ji)(ji)合(he)成橡膠(jiao)。這將極大(da)(da)拓展(zhan)有機(ji)硅(gui)(gui)(gui)產(chan)(chan)業(ye)的(de)(de)(de)市(shi)場(chang)空(kong)間,同時(shi)將帶動硅(gui)(gui)(gui)油(you)、硅(gui)(gui)(gui)烷偶聯劑和硅(gui)(gui)(gui)樹脂等其他有機(ji)硅(gui)(gui)(gui)產(chan)(chan)品的(de)(de)(de)消費。