A FTIR and SEM study of PS radiation grafted fluoropolymers:: influence of the nature of the ionizing radiation on the film structure
A FTIR and SEM study of PS radiation grafted fluoropolymers:: influence of the nature of the ionizing radiation on the film structure
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DOI：
10.1016/s0168-583x(99)00119-6
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发表时间：
1999-05-01
影响因子：
1.3
通讯作者：
Le Moël, A
中科院分区：
文献类型：
--
作者：
Aymes-Chodur, C;Betz, N;Le Moël, A
本文研究了聚偏氟乙烯（PVDF）和聚偏氟乙烯/六氟丙烯共聚物（VDF/HFP）辐射接枝聚苯乙烯（PS）的聚合物膜的结构。这些含氟聚合物的不同之处在于共聚物中存在少量的HFP，这使PVDF增塑并有利于链的流动性。根据不同的参数，如辐照类型（快速重离子和γ-射线），吸收剂量，接枝时间和基板性质的过氧化物接枝动力学结果。最低吸收剂量为10 kGy，这足以引发显著的接枝。利用傅里叶变换红外光谱、透射光谱和内反射光谱计算了不同深度的PS接枝率。在仅PVDF的情况下，观察到厚度的PS梯度，其在γ射线引发的情况下比在快速重离子引发的情况下更高。这可能是由于PS扩散在重离子辐照后形成的潜径迹中加速了。无论是哪种辐照方式，PVDF的接枝率都高于其共聚物，这是由于结晶度的差异。通过扫描电子显微镜观察PS层的形成。在小的接枝率，PVDF球晶被覆盖的PS的网络，往往形成一个连续的层时，增加接枝率;而在共聚物的情况下，PS似乎更快地渗透在本体中，使表面层的形成被延迟。我们的研究结果表明，使用不同种类的电离辐射诱导的接枝膜的结构的差异。(C)1999 Elsevier Science B. V.保留所有权利。
This study deals with the structure of polymeric films obtained by radiation grafting of polystyrene (PS) in poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride/hexafluoropropylene) P(VDF/HFP). These fluoropolymers differ by the small HFP amount present in the copolymer, which plasticizes PVDF and favors the chain mobility. Peroxide grafting kinetic results obtained according to different parameters such as the irradiation type (swift heavy ions and gamma-rays), the absorbed dose, the grafting time and the substrate nature are presented. The lowest absorbed dose is 10 kGy, which is enough to initiate significant grafting. Fourier Transform IR, transmission and Internal Reflection Spectroscopy are used to calculate the PS grafting yields at different depths. In the case of PVDF only, a PS gradient in the thickness is observed which is higher in the case of a gamma-rays initiation than in that of a swift heavy ions one. This might be explained by the fact that the PS diffusion is accelerated in the latent tracks formed after the heavy ions irradiation. Whatever the radiation type, the grafting yield is higher in PVDF than in its copolymer, which is due to the difference of crystallinity. The PS layer formation is observed by Scanning Electron Microscopy. At small grafting yields, the PVDF spherulites are covered with a network of PS that tends to form a continuous layer when increasing the grafting yield; whereas in the case of copolymer, PS seems to penetrate faster in the bulk, so that the formation of the superficial layer is delayed. Our results show that using different kinds of ionizing radiations induces differences in the structure of the grafted films. (C) 1999 Elsevier Science B.V. All rights reserved.