The influence of the addition of graphene nanoplatelets (GNPs) on the intra/inter – molecular segmental motions of poly(ethylene-co-vinyl alcohol) (EVOH) was assessed by means of dielectric thermal analysis (DETA). The relaxation spectra were studied in terms of the dielectric permittivity (ε’) and the dielectric loss tangent (tan δ) at wide ranges of frequency (from 10⁻² to 10⁷ Hz) and temperature (from -150 to 140 ºC). Two relaxation zones were disthinguished. Below the glass transition temperature (T_g), two β-relaxations were observed, which are characteristic local modes of mobility of the EVOH side groups, and related to the influence of the different surroundings of ethylene or vinyl alcohol units. At higher temperatures, the dielectric α-relaxation in the vicinities of the glass transition of EVOH was determined. The thermal activation of the β-relaxations was explained by an Arrhenius model, and showed activation energies (E_a) around 55 and 80 kJ•mol⁻¹. The α-relaxation was explained by the Vogel-Fulcher-Tammann-Hesse (VFTH) model. The study of the segmental dynamics showed an increase in the dynamic fragility parameters with the addition of GNPs. The permittivity was increased at preferential concentrations of GNPs. In particular, the addition of GNPs up to 0.5 wt% increased the dielectric permittivity of the electrospun EVOH/GNPs nanocomposite fibers, specially at low frequencies.

通过介电热分析（DETA）评估了石墨烯纳米片（GNP）的添加对聚（乙烯-共-乙烯醇）（EVOH）分子内/分子间运动的影响。研究了在宽频率（10 ^-2到10 ⁷ Hz）和温度（-150到140℃）范围内的介电常数（ε'）和介电损耗正切（tanδ）的弛豫谱。区分出两个松弛区。在玻璃化转变温度（T _g）以下，两个β观察到松弛，这是EVOH侧基的特征性局部迁移模式，并且与乙烯或乙烯醇单元的不同周围环境的影响有关。在较高的温度下，确定了EVOH的玻璃化转变附近的介电α松弛。β松弛的热活化由Arrhenius模型解释，并且显示出在55和80kJ·mol ^-1附近的活化能（E _a）。该α松弛由Vogel-Fulcher-Tammann-Hesse（VFTH）模型解释。对分段动力学的研究表明，随着GNP的加入，动态脆性参数增加。在优选的GNP浓度下，介电常数增加。特别地，添加高达0.5wt％的GNP增加了电纺EVOH / GNPs纳米复合纤维的介电常数，特别是在低频下。