Surface hardening of poly(methyl methacrylate) by electron irradiation
Surface hardening of poly(methyl methacrylate) by electron irradiation
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DOI：
10.1016/j.nimb.2005.03.007
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发表时间：
2005-08-01
影响因子：
1.3
通讯作者：
Jun, HY
中科院分区：
文献类型：
--
作者：
Cho, SO;Jun, HY
聚甲基丙烯酸甲酯（PMMA）是一种辐射降解聚合物，在高通量电子辐照下表现出机械硬化行为。当电子影响小于1 × 10(15) cm（-2）时，PMMA表现出正常的降解行为。然而，当电子影响大于1 × 10(17) cm（-2）时，辐照PMMA的力学性能得到了极大的改善。辐照实验采用大块片状PMMA样品，电子能量为60 keV。在7.5 × 10(17) cm（-2）的电子影响下，辐照PMMA的表面硬度从0.29 GPa增加到2.8 GPa，弹性模量从5.6 GPa增加到22.9 GPa。拉曼光谱和XPS光谱均表明，电子辐照下聚合物材料的表面硬化是由氢化非晶碳转变而成的。共聚焦拉曼光谱表明，相变发生在从表面到深度的电子范围内。(c) 2005 Elsevier B.V.版权所有
Poly(methyl methacrylate) (PMMA), known as a radiation-degrading polymer, showed mechanically hardening behavior under a high-fluence electron irradiation. When the electron fluence was less than 1 x 10(15) cm(-2), PMMA showed normal degrading behavior. However, at electron fluence higher than 1 x 10(17) cm(-2), the mechanical properties of the irradiated PMMA were tremendously improved. Bulk plate PMMA samples and an electron energy of 60 keV were employed in the irradiation experiments. The surface hardness of the irradiated PMMA increased from a pristine value of 0.29 GPa up to 2.8 GPa and the elastic modulus increased from 5.6 GPa to 22.9 GPa at an electron fluence of 7.5 x 10(17) cm(-2). Both Raman spectra and XPS spectra showed that the surface hardening was attributed to the transformation of polymeric materials into hydrogenated amorphous carbon under the electron irradiation. Confocal Raman spectra showed that the transformation occurred from the surface to the depth of electron range. (c) 2005 Elsevier B.V. All rights reserved.