Poly(adipate⁃butylene terephthalate) (PBAT) was grafted with glycidyl methacrylate (GMA) to prepare PBAT⁃GMA, which was subsequently blended with PBAT and poly(lactic acid) (PLA) to obtain PBAT/PBAT⁃GMA/PLA blends. The effects of PBAT⁃GMA content on the mechanical properties, micromorphology, barrier properties, and degradability of PBAT/PBAT⁃GMA/PLA films were systematically studied. The results indicate that increasing the mass fraction of PBAT⁃GMA significantly enhanced the mechanical properties of the films. When the mass fraction of PBAT⁃GMA is 15%, the tensile strength increased from 15.28 MPa (longitudinal) and 12.51 MPa (transverse) without PBAT⁃GMA to 25.61 MPa (longitudinal) and 19.59 MPa (transverse), respectively. Similarly,the elongation at break improved from 109.23% (longitudinal) and 141.32% (transverse) to 217.63% (longitudinal) and 311.22% (transverse). It demonstrates that the incorporation of PBAT⁃GMA effectively enhanced the compatibility between PBAT and PLA,thereby improving the mechanical properties of the blend. Moreover, with higher PBAT⁃GMA content, the barrier properties of PBAT/PBAT⁃GMA/PLA films were also significantly improved.However,the degradation rate of PBAT/PBAT⁃GMA/PLA films decreased slightly with the increase of PBAT⁃GMA mass fraction, indicating that the durability of the materials was improved.

In this paper, a kind of composite phase change material (capric?lauric acid/expanded vermiculite) using expanded vermiculite as the matrix and capric?lauric acid binary eutectic as the adsorbent was fabricated by vacuum impregnation technology. The chemical compatibility, morphology, stability，thermal?physical properties and reliability of the prepared composite capric?lauric acid/expanded vermiculite were investigated by fourier transform infrared spectrum (FT?IR), scanning electronic microscope (SEM), thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC) and thermal cycling test. The melting and solidification phase transition temperatures of capric?lauric acid/expanded vermiculite are 18.42 ℃ and 17.51 ℃, respectively. The latent heat of melting and solidification phase transition are 66.9 J/g and 62.9 J/g, respectively. Besides, the encapsulation amount of capric?lauric acid in expanded vermiculite can reach 52.97%, and it has good thermal stability between working temperature. Moreover, the capric?lauric acid/expanded vermiculite was used to substitute for a certain proportion of fine sand to prepare thermal storage mortar, the mechanical and thermal performance of capric?lauric acid/expanded vermiculite?based mortar was evaluated. The test result shows that prepared capric?lauric acid/expanded vermiculite?based thermal storage mortar is a potential material for building heat regulation and energy saving.

In order to study the salt precipitation law of the NaCl?Na₂SO₄?H₂O ternary system at a temperature of 298.15 K, the Pitzer model was used to predict and calculate the activity coefficient and solubility of the system, and the variation of the activity coefficients of Na⁺, Cl^- and SO {}_{\mathrm{4}}^{\mathrm{2}-} and the corresponding phase diagram of the ternary system were analyzed. The results show that with the increase of the Na₂SO₄ mass fraction, the activity coefficients of Cl^- and SO {}_{\mathrm{4}}^{\mathrm{2}-} have no obvious change, while the activity coefficient of Na⁺ icreases first and then decreases. When the mass fraction of Na₂SO₄ in the liquid phase is less than 6.8%, the average change rate of the increase in the activity coefficient of Na⁺ is 4.4%. When the mass fraction of Na₂SO₄ in the liquid phase is between 6.8% and 14.9%, the average change rate of decrease in the activity coefficient of Na⁺ is 4.1%, when the mass fraction of Na₂SO₄ in the liquid phase reaches 14.9%, the activity coefficient of Na⁺ decreases fastest, and the average change rate is 8.0%; when the mass fraction of NaCl in the liquid phase is greater than 22.9% and the mass fraction of Na₂SO₄ is less than 6.8% ,as the water evaporates, NaCl precipitates first and Na₂SO₄ precipitates later; when the liquid phase mass fraction of NaCl is 14.0%～22.9% and the mass fraction of Na₂SO₄ is 6.8%～14.9%, the precipitation order is reversed.