Porous poly(vinyl alcohol) (PVA)/phase change microcapsule composites with shape memory properties were prepared by physical foaming, cycles of freezing–thawing and freeze drying. The effects of phase change microcapsules on pore structure, phase change energy storage capacity, thermal stability, crystallinity, mechanical properties, shape memory properties and water absorption and retention of the porous composites were investigated. With an increase of the proportion of phase change microcapsules, the pore density, pore size and water absorption and retention of the porous composite materials were decreased, while the phase change energy storage performance was improved and ΔH_m was up to 31.22 J g⁻¹. The phase change energy storage of the porous composites was stable even after 50 phase transition cycles. Meanwhile, the thermal stability of the porous composites was also not affected by the addition of phase change microcapsules. The entanglement of PVA molecular chains in the porous composites was affected by the microcapsules embedded in the matrix of PVA during freezing–thawing cycles, resulting in a change of crystallinity and mechanical properties of the porous composites. The porous composites with phase change energy storage capacity also showed good shape memory performance with shape recovery rate of 100% even after multiple deformation, which was expected to expand the multi‐field application of dual‐functional materials. © 2020 Society of Chemical Industry

中文翻译：

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多孔聚乙烯醇/相变微胶囊复合材料的同时相变储能和热响应形状记忆性能

通过物理发泡，冷冻-融化和冷冻干燥循环，制备了具有形状记忆特性的多孔聚乙烯醇（PVA）/相变微胶囊复合材料。研究了相变微胶囊对多孔复合材料的孔结构，相变储能能力，热稳定性，结晶度，机械性能，形状记忆性能以及吸水率和保留率的影响。随着相变微胶囊，孔密度，孔尺寸和水的吸收和多孔复合材料的保留的比例被降低，而相变储能性能得到了改善，Δ ħ_米高达31.22Ĵ克^{- 1个}。即使在50个相变循环之后，多孔复合材料的相变储能也是稳定的。同时，添加相变微胶囊也不会影响多孔复合材料的热稳定性。PVA分子链在多孔复合材料中的缠结在冻融循环中受到嵌入PVA基质中的微囊的影响，从而导致多孔复合材料的结晶度和机械性能发生变化。具有相变储能能力的多孔复合材料即使在多次变形后也具有良好的形状记忆性能，形状恢复率达100％，这有望扩大双功能材料的多领域应用。©2020化学工业协会