PAM/PEGDA相变储能导电木膜的制备与表征

Preparation and characterization of PAM/PEGDA phase change energy storage conductive wood films

以轻木为基材,以丙烯酰胺(AM)为改性单体,添加聚乙二醇二丙烯酸酯(PEGDA)为相变基元和交联剂,通过自由基聚合的方法制备了一种具有固-固相变储能的木膜。通过傅里叶红外光谱测试、机械性能测试、X射线衍射、差示扫描量热法以及热失重测试分析了样品的结构与性能。结果表明,轻木基板浸渍AM和PEGDA后力学性能显著提升;PEGDA含量为2.5%(质量分数)时,木膜拉伸强度取得最大值2.85 MPa;断裂伸长率在0.5%(质量分数)时取得最大值6.06%;PEGDA含量为2.0%(质量分数)时,木膜结晶度取得最大值47.7%;木膜的相变潜热焓在PEGDA含量2.0%(质量分数)时,达最大值25.63 J/g;木膜具有各向异性导电性能,沿纤维方向(x方向)最大电导率为2.99 S/m,垂直纤维方向(y方向)最大电导率为2.01 S/m;木膜浸渍0.5 mol/L FeCl 3溶液比浸渍相同浓度NaCl和AlCl 3溶液的电导率高,浸渍NaCl、AlCl 3和FeCl 3后,沿纤维方向木膜的电导率最大值分别为0.01,0.02和2.99 S/m,垂直于纤维方向电导率最大分别为0.03,0.04和2.01 S/m。聚丙烯酰胺/聚乙二醇二丙烯酸酯(PAM/PEGDA)相变储能导电木膜有望作为新型木基环保导电薄膜材料应用于柔性电子可穿戴领域及绿色建筑材料。

In this study,a type of conductive wood films with solid-solid phase change energy storage function was prepared using balsa wood as the raw material,acrylamide(AM)as the modified monomer,and polyethylene glycol diacrylate(PEGDA)as the phase change element and crosslinking agent.The wood films were formed through free radical polymerization reactions.The Fourier infrared spectroscopy,mechanical performance testing,X-ray diffraction,differential scanning calorimetry,and thermal weight loss methods were used to characterize the structure and performance of the samples.Within the experimental dosage range,the measurement and analyses results showed that the mechanical properties of the balsa wood substrate composited with AM and PEGDA were significantly improved compared with the balsa delignification template.When the PEGDA content was 2.5%(mass fraction),the wood film had the best tensile strength performance,achieving a maximum value of 2.85 MPa;when the PEGDA content was 0.5%(mass fraction),the maximum elongation at break was 6.06%;when the PEGDA content was 2.0%(mass fraction),the wood film crystallinity achieved the maximum value of 47.7%.The wood films had the function of phase change energy storage.The latent heat of phase change of wood films reached the maximum value of 25.63 J/g when the content of PEGDA was 2.0%(mass fraction).At this time,the function of phase change energy storage was the best.Due to the anisotropy of wood,the conductive wood films also had an isotropic conductivity.The maximum conductivity along the fiber lumen direction(x direction)was 2.99 S/m,and the maximum conductivity perpendicular to the fiber lumen direction(y direction)was 2.01 S/m.In order to improve the electrical conductivity,the wood films were immersed in different salt solutions for different times and then the resistances were measured.The wood films immersed in 0.5 mol/L FeCl 3 solution had higher electrical conductivities than the same concentration of NaCl and AlCl 3 solution.The conductivities were much higher after the samples were immersed in NaCl,AlCl 3 and FeCl 3 solutions.The maximum conductivity of the wood film along the fiber direction was 0.01 S/m,0.02 S/m and 2.99 S/m,respectively,and the maximum conductivity of the wood film perpendicular to the fiber direction was 0.03 S/m,0.04 S/m and 2.01 S/m,respectively.Polyacrylamide/polyethylene glycol diacrylate(PAM/PEGDA)is a type of conductive wood films with phase change energy storage function.It is also a new type of wood-based environmentally friendly film material.It will have huge application potential in the field of flexible electronic wearables and green building materials.