聚烯烴薄膜的電暈放電使其表面產生極性基團增加表面能，提高該薄膜的浸潤性和粘合性。電暈處理時主要的化學機理是氧化作用同時還產生一定的表面交聯區而提高粘接強度。

電(dian)(dian)(dian)暈放電(dian)(dian)(dian)的本(ben)(ben)質(zhi)聚(ju)烯(xi)烴(jing)薄(bo)膜需(xu)粘(zhan)合(he)、印刷、擠(ji)出涂層(ceng)、金屬化(hua)、復合(he)和熱封時表面(mian)就要處(chu)(chu)理(li)(li)(li)。在(zai)眾多的處(chu)(chu)理(li)(li)(li)辦法中工(gong)業上(shang)廣泛采用的是電(dian)(dian)(dian)暈放電(dian)(dian)(dian)處(chu)(chu)理(li)(li)(li)法。電(dian)(dian)(dian)暈處(chu)(chu)理(li)(li)(li)聚(ju)合(he)物表面(mian)能提高牯接強度的理(li)(li)(li)論有：生成了(le)永(yong)久極化(hua)的駐極體(ti)、排除了(le)弱鍵層(ceng)、提高了(le)表面(mian)粗(cu)糙度、氧化(hua)后引人了(le)極性基團等。那么電(dian)(dian)(dian)暈放電(dian)(dian)(dian)的本(ben)(ben)質(zhi)是什(shen)么呢?

空(kong)氣在(zai)(zai)(zai)(zai)一(yi)(yi)般情況(kuang)下是(shi)(shi)良好的(de)電(dian)(dian)(dian)(dian)(dian)(dian)絕緣介質，但它處于足夠強的(de)電(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)中時會(hui)被擊(ji)穿(chuan)即空(kong)氣分(fen)(fen)(fen)子(zi)(zi)(zi)離(li)子(zi)(zi)(zi)化而(er)傳(chuan)導(dao)電(dian)(dian)(dian)(dian)(dian)(dian)流。迅速(su)放電(dian)(dian)(dian)(dian)(dian)(dian)會(hui)在(zai)(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)之間產生(sheng)電(dian)(dian)(dian)(dian)(dian)(dian)弧或火花，若(ruo)將一(yi)(yi)種(zhong)固體薄膜(mo)置(zhi)于兩電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)之間，中斷了導(dao)電(dian)(dian)(dian)(dian)(dian)(dian)通路不(bu)(bu)再(zai)產生(sheng)局部的(de)熾熱(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)弧而(er)在(zai)(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)間擴散(san)成(cheng)輝光(guang)，這種(zhong)在(zai)(zai)(zai)(zai)大氣壓下空(kong)氣帶蘭色(se)光(guang)的(de)放電(dian)(dian)(dian)(dian)(dian)(dian)稱(cheng)為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)暈(yun)電(dian)(dian)(dian)(dian)(dian)(dian)暈(yun)現象起源于電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)間氣體中存(cun)在(zai)(zai)(zai)(zai)的(de)少數雜散(san)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)，若(ruo)兩極(ji)(ji)問施(shi)高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)壓，產生(sheng)強電(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)能(neng)加(jia)速(su)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)朝正(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)沖擊(ji)途中的(de)氣體分(fen)(fen)(fen)子(zi)(zi)(zi)，撞出分(fen)(fen)(fen)子(zi)(zi)(zi)中的(de)軌(gui)道電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)，留下正(zheng)離(li)子(zi)(zi)(zi)和另(ling)(ling)一(yi)(yi)個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)，該電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)可繼續沖擊(ji)其它分(fen)(fen)(fen)子(zi)(zi)(zi)。另(ling)(ling)一(yi)(yi)方面(mian)沖擊(ji)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)能(neng)提高(gao)軌(gui)道電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)至不(bu)(bu)穩定(ding)(ding)狀態使其在(zai)(zai)(zai)(zai)更高(gao)能(neng)量的(de)軌(gui)道上成(cheng)為(wei)受(shou)激(ji)分(fen)(fen)(fen)子(zi)(zi)(zi)，很(hen)快地就在(zai)(zai)(zai)(zai)氣體中充滿(man)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)、正(zheng)離(li)子(zi)(zi)(zi)、受(shou)激(ji)分(fen)(fen)(fen)子(zi)(zi)(zi)、熱(re)(re)和光(guang)，這些(xie)就是(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)暈(yun)現象。受(shou)激(ji)的(de)分(fen)(fen)(fen)子(zi)(zi)(zi)是(shi)(shi)不(bu)(bu)穩定(ding)(ding)的(de)能(neng)自發地分(fen)(fen)(fen)解成(cheng)自由基、離(li)子(zi)(zi)(zi)和光(guang)子(zi)(zi)(zi)。因(yin)此電(dian)(dian)(dian)(dian)(dian)(dian)暈(yun)放電(dian)(dian)(dian)(dian)(dian)(dian)時極(ji)(ji)性基團能(neng)引(yin)人聚合物表面(mian)形(xing)成(cheng)高(gao)的(de)表面(mian)能(neng)和強的(de)粘接力(li)。例如一(yi)(yi)種(zhong)含(han)氧(yang)(yang)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)暈(yun)是(shi)(shi)一(yi)(yi)種(zhong)活(huo)(huo)性氧(yang)(yang)的(de)混合物存(cun)在(zai)(zai)(zai)(zai)于電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)之間——包括(kuo)元素氧(yang)(yang)0、臭氧(yang)(yang)03和活(huo)(huo)性氧(yang)(yang)02’，高(gao)度活(huo)(huo)性的(de)氧(yang)(yang)能(neng)迅速(su)地與分(fen)(fen)(fen)子(zi)(zi)(zi)反(fan)應，最終就在(zai)(zai)(zai)(zai)薄膜(mo)表面(mian)形(xing)成(cheng)含(han)氧(yang)(yang)官能(neng)團。

提(ti)(ti)高電(dian)暈(yun)放電(dian)時(shi)的(de)(de)功率就(jiu)會產生更多的(de)(de)離子(zi)且能(neng)提(ti)(ti)高粒(li)子(zi)的(de)(de)平均動(dong)能(neng)，由薄膜表(biao)面(mian)的(de)(de)離子(zi)能(neng)量(liang)大小反映電(dian)暈(yun)處理(li)的(de)(de)程度(du)(du)。提(ti)(ti)高相對(dui)濕度(du)(du)時(shi)放電(dian)能(neng)量(liang)就(jiu)增加，因此在(zai)(zai)高濕度(du)(du)下(xia)放電(dian)處理(li)會成(cheng)比側(ce)地提(ti)(ti)高含羧基官能(neng)團的(de)(de)濃度(du)(du)。在(zai)(zai)表(biao)面(mian)產生極性(xing)化學基團就(jiu)能(neng)提(ti)(ti)高它(ta)的(de)(de)粘(zhan)合(he)力和對(dui)其它(ta)材料浸(jin)潤(run)性(xing)。

電暈(yun)放電處(chu)理(li)后的變(bian)化

(一(yi)) 化(hua)學變化(hua)一(yi)氧化(hua)作(zuo)用

電(dian)暈放電(dian)的主要化(hua)(hua)學變化(hua)(hua)是(shi)(shi)氧(yang)化(hua)(hua)作用，其(qi)次是(shi)(shi)表面分(fen)(fen)(fen)子(zi)發(fa)生交聯限制部分(fen)(fen)(fen)分(fen)(fen)(fen)子(zi)的運(yun)動并增加其(qi)分(fen)(fen)(fen)子(zi)量(liang)。通過紅外(wai)光譜、電(dian)子(zi)光譜、電(dian)子(zi)自(zi)旋共振等(deng)多(duo)種分(fen)(fen)(fen)析能(neng)確證在薄膜表面存在這些化(hua)(hua)學官(guan)能(neng)團(tuan)。

一(yi)個自由氧原子能擊(ji)碎一(yi)個聚臺物(wu)分子成為兩個井迅速地生成新的基團，原子氧對聚合(he)物(wu)的氧化迅速地發生在(zai)表面形成氫過氧化物(wu)和(he)基團如R00H、ROOR’、ROOOR’等，這些基團的存在(zai)使(shi)聚烯烴等塑料薄膜易于粘(zhan)合(he)和(he)印(yin)刷。

(二) 物理(li)變化(hua)

電(dian)(dian)(dian)暈放電(dian)(dian)(dian)處理能(neng)改變(bian)聚烯(xi)烴(jing)薄(bo)膜的(de)表(biao)(biao)面構(gou)型，表(biao)(biao)面構(gou)型的(de)變(bian)化可用掃描電(dian)(dian)(dian)子顯微(wei)鏡(s肼)觀(guan)察而表(biao)(biao)面構(gou)型的(de)變(bian)化也會(hui)影響薄(bo)膜粘(zhan)合(he)性(xing)能(neng)。電(dian)(dian)(dian)暈放電(dian)(dian)(dian)也是一種高能(neng)量(liang)的(de)粒子轟擊薄(bo)膜表(biao)(biao)面，表(biao)(biao)面上會(hui)生成微(wei)小(xiao)的(de)斑點(dian)，它即是提高粘(zhan)合(he)作用的(de)物理因素在空氣中進(jin)行電(dian)(dian)(dian)暈處理可使薄(bo)膜表(biao)(biao)面粗化．

電暈(yun)放(fang)電時在薄膜表(biao)面(mian)形(xing)成(cheng)的(de)化學組成(cheng)很大程度(du)上受控于兩電極之(zhi)間的(de)氣(qi)體組成(cheng)以及薄膜本身和添加劑(ji)的(de)情況。對薄膜表(biao)面(mian)電暈(yun)處理(li)的(de)有效性取決于放(fang)電時的(de)相對濕(shi)度(du)，濕(shi)度(du)越大所需的(de)電暈(yun)放(fang)電時間越長。

標簽：薄膜電暈處理提高粘接性的機理 、