Due to the excellent biodegradability of polylactic acid compared to petroleum-based plastics, it has enabled large-scale substitution of petroleum-based plastics in the field of disposable injection molding, foaming and blown film to solve the problem of increasingly serious “white pollution†and has now been achieved. The world's vigorous promotion. In view of this, in recent years, China has also promulgated corresponding laws and regulations prohibiting the use of non-degradable disposable plastics such as PP, PE and PS. In view of the poor heat resistance, high price, and poor toughness of polylactic acid, the Bio-based Polymer Materials Research Team of the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences has conducted in-depth research and made a series of progresses.
In the previous work, the team successfully solved the key problem of poor heat resistance of polylactic acid by synthesizing a biobased crystalline nucleating agent for polylactic acid, thereby expanding the application range of polylactic acid in traditional plastics and other related fields, but this resistance Thermal modification will further increase the cost of polylactic acid, further limiting its application in disposable applications. At present, higher prices (compared to traditional petroleum-based general-purpose plastics) are the key factors that limit the widespread use of polylactic acid. In recent years, in order to reduce the application cost of polylactic acid and maintain the biodegradability of polylactic acid, the use of inexpensive, widely available/biodegradable and continuously utilized biomass such as lignin, cellulose, bamboo powder and starch and other biomass Filling composite polylactic acid has become the most rapidly developing direction in environmental plastics.
However, in the polylactic acid/biomass composites, due to the significant difference in hydrophilicity and hydrophobicity between the polylactic acid and the cellulose filler, starch, or bamboo powder, the interface compatibility of the polylactic acid/biomass composite material is very poor. At the same time, general biomass fillers belong to large-size rigid particles, and their presence in the polylactic acid matrix is ​​prone to stress concentration and induce cracks, resulting in very poor fracture strength and ductility of the composite materials and severely impeded application. Therefore, the study of the effect of changes in the hydrophilicity and hydrophobicity of the biomass filler on polylactic acid/biomass composites on interface compatibility and the ability to reduce the ability of biomass to induce cracking in polylactic acid matrices will be important for the development and application of such materials. significance.
In response to this problem, the team used for the first time the use of highly reactive bio-based compatibilizers such as Epoxidized Soybean Oil (ESO), Epoxy Epoch, Itaconic Epoxy, Citric Acid Epoxy, etc. This kind of composite material has undergone interface modification research, and has prepared a bio-based biodegradable environment-friendly polylactic acid composite material with high performance and meeting application requirements. At the same time, a detailed mechanism study and analysis of how high activity reactive biobased compatibilizers improve the interfacial compatibility between hydrophilic biomass rigid particles and hydrophobic polylactic acid matrix (Figure 1).
It was found that the main reason why the high activity reactive bio-based compatibilizer improves the interfacial compatibility of polylactide/biomass filler is that it is enriched to the surface of the biomass filler during reactive extrusion processing, thereby changing the affinity of the biomass filler. The nature of the water interface has enabled the hydrophobic polylactic acid to infiltrate the interface of the hydrophilic biomass filler, thereby improving the interface compatibility and mechanical properties of this type of composite material. Related results have been published (Carbohydrate Polymers, 2013, 92: 810–816 Carbohydrate Polymers, 2013, 94: 235–243; Carbohydrate Polymers, 2013, 95: 77–84; Composite Science and Technology, 2014, 94: 16-22; Composites Science and Technology, 2014, 90, 9–15; Industrial and Engineering Chemistry Research, 2014, 53: 10653-10659; Journal ofApplied Polymer Science, 2015, DOI: 10.1002/APP.41220; International Journal of Biological Macromolecules, 2015, in press ), has been authorized two Chinese patents (CN201210123934 .5; CN20121 0062675.X). Finally, through this method, the researchers prepared a variety of injection-molded, plastic disposable degradable products that meet the application requirements (Figures 2, 3). It is expected that the “white pollution†environmental problems can be effectively mitigated in the near future.
Kitchen Cabinets ,Kitchen Pantry Storage,Modular Kitchen Cabinets,Menards Kitchen Cabinets
Ningbo Oulin Import&Export Co.,Ltd. , https://www.oulin-oversea.com