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首页> 外文期刊>Journal of Applied Polymer Science >CORRELATED ELECTRON SPIN-RESONANCE AND INFRARED SPECTROSCOPIC STUDY OF THE POSTFORMATION AUTO-OXIDATION PHENOMENON IN PLASMA-POLYMERIZED 4-VINYL PYRIDINE FILMS
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CORRELATED ELECTRON SPIN-RESONANCE AND INFRARED SPECTROSCOPIC STUDY OF THE POSTFORMATION AUTO-OXIDATION PHENOMENON IN PLASMA-POLYMERIZED 4-VINYL PYRIDINE FILMS

机译：等离子体聚合的4-乙烯基吡啶薄膜的后自氧化现象的相关电子自旋共振和红外光谱研究

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Plasma polymerization of 4-vinyl pyridine (4-VP) proceeds through a gas-phase free radical mechanism to yield a film that retains much of the organic functionality of the monomer. During the deposition process, free radicals, which have been shown to quickly react with oxygen, are trapped to yield a film with a nascent peroxy radical density of 2.9 X 10(18) spins/g as quantified by electron spin resonance (ESR) spectroscopy. In air at room temperature, peroxy radicals in the film react to produce carbonyl, hydroxyl, and ether structures in the polymer that was monitored using infrared (IR) spectroscopy. The free radical population was found to decay rapidly at first and then reach an apparent steady state after 30 hr. As the spin density decreases, a concomitant growth of vibrational modes associated with oxygen-containing functional groups was observed in the IR spectrum of the film. The relative population of oxygen-containing groups continued to increase even after the free radical population reached steady state. This slow, auto-oxidative effect may be attributed, in part, to free radical centers that are anchored to the polymer chain in regions of high crosslinking. In such regions, limited segmental mobility may limit the rate of radical-radical recombination (termination) processes relative to oxidative radical-center. (C) 1996 John Wiley & Sons, Inc. [References: 16]
机译：4-乙烯基吡啶（4-VP）的等离子体聚合通过气相自由基机理进行，从而得到保留了单体大部分有机官能度的薄膜。在沉积过程中，被证明可以与氧气快速反应的自由基被捕获，得到的薄膜的初生过氧自由基密度为2.9 X 10（18）spins / g，通过电子自旋共振（ESR）光谱定量。在室温下的空气中，薄膜中的过氧自由基反应生成聚合物中的羰基，羟基和醚结构，可使用红外（IR）光谱法对其进行监测。发现自由基种群首先迅速衰减，然后在30小时后达到明显的稳态。随着自旋密度降低，在膜的IR光谱中观察到与含氧官能团相关的振动模式的同时增长。甚至在自由基数量达到稳态后，含氧基团的相对数量仍继续增加。这种缓慢的自氧化作用可能部分归因于在高交联区域中锚定到聚合物链上的自由基中心。在这样的区域中，有限的节段迁移率可能会限制自由基-自由基重组（终止）过程相对于氧化自由基中心的速率。 （C）1996 John Wiley＆Sons，Inc. [参考：16]

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