Study On Preparation And Barrier Mechanism Of High-Performance Paper-Based Barrier Materials

In this study,high-performance paper-based barrier materials were prepared using double-layer and single-layer coating techniques to achieve water,oil,and thermal oil resistance,meeting the performance requirements of paper-based packaging materials.The paper-based composites exhibited excellent barrier function and demonstrated exceptional oil-proof performance under high-temperature extreme environments.To achieve water resistance in the emulsion coating film,the study utilized organosilicon-modified acrylate emulsion,which reduced the surface energy of the acrylate emulsion.A single-factor test was used to determine the temperature during the polymerization reaction of the emulsion,as well as the range of temperature,amount of emulsifier,and amount of silicone monomer.The response surface optimization test,designed according to the Box-Benhnken central combined experimental design principle,yielded an optimal experimental process with a reaction temperature of 80℃,emulsifier dosage of 3.7%,and silicone dosage of5.1%.The conversion rate was 95.49%and the gel rate was 0.067%.The conversion rate obtained from the validation experiment was consistent with the model deduction results.Using the optimized conditions,silicone-modified acrylate emulsions with silicone content ranging from 5%to 9%were prepared as the waterproof layer in the barrier coating.The study utilized chitosan and sodium alginate,two commonly used biomass-based polymers,as the oil-proof coating,achieving functional superposition of the waterproof and oil-proof layers through the double-layer coating.The resulting biomass-based polymer-silicone acrylic emulsion coated paper exhibited a Cobb value of 5.3 g/m~2,and both Kit rating could reach 12,effectively blocking the penetration of castor oil at 80°C within 24h.The Cobb value of sodium alginate coated paper was much higher than that of uncoated paper,at 41.6 g/m~2,due to the water solubility of sodium alginate,reducing the waterproof performance of the coated paper.Nonetheless,the Kit rating could reach up to 10,effectively slowing down the rate of castor oil penetration at 80°C within 24h.FT-IR spectra results indicated that no chemical reaction occurred between the coatings,scanning electron microscopy showed good film formation on the surface of the biomass-based polymer-silicone acrylic emulsion coated paper,and the result of thermogravimetry showed that the double-layer coating increased the thermal decomposition temperature of the overall barrier coating,effectively improving the thermal stability of the coating.To enhance the production process of double-layer coating,a heterogeneous grafting polymerization method was employed to prepare a reactive curing coating that solves the problem of mutual incompatibility between the water and oil repellent components.The previous coating process faced complexity,resulting in excessively thick coatings that caused paper deformation and cracking during the drying process.Polyvinyl alcohol was used as the base coating to fill the fiber gap and provide grafting sites for PDMS-NCO to prepare the PVA-PDMS coated paper.The structure of the reactive cured coating was characterized through infrared analysis and nuclear magnetic resonance.The microstructure of the coating was observed through scanning electron microscopy and atomic force microscopy,and the contact angle of the material surface was measured.Performance tests indicated that the PVA-PDMS coated paper achieved the best barrier effect at the PVA/PDMS mass ratio of 3:1,with a Cobb value of 11 g/m~2 and Kit rating up to 12.The material successfully blocked castor oil at 80℃within 24 hours,with excellent thermal stability.This preparation method for high-performance paper-based barrier material provides a novel approach to creating paper-based composites.Subsequently,a microscopic model of the high-performance paper-based barrier material was constructed based on experimental data,and the barrier mechanism of the material was analyzed from a molecular perspective.An adaptive neuro-fuzzy inference system(ANFIS)was used to construct a prediction model of the coating structure under high-temperature environments,resolving the issue of the barrier mechanism’s quantitative analysis using traditional thermochemical kinetic models under extreme high-temperature environments.The ANFIS prediction model was created through two algorithms:the grid partitioning algorithm and the subtractive clustering algorithm.The degree of adaptation of the affiliation functions determined by the two algorithms to this experimental data was compared.Results showed that the prediction model using the grid partitioning method was a better fit for the experimental data,with an RMSE value of 7.00383 and an R~2of 0.9644 between the model prediction data and actual data...