Research on constructing a physical barrier chemical anchoring dual inhibition system to slow down the migration of PLA plasticizers

Research background and core ideas: Polylactic acid (PLA), as a biodegradable biobased resin, has received continuous attention in food and daily chemical packaging films and containers. However, PLA itself is brittle and has a narrow processing window, often requiring the use of plasticizers to improve flexibility; Small molecule plasticizers may migrate to the surface of materials during storage and use, leading to issues of food contact safety and packaging performance degradation. A study published in Volume 58 of Food Packaging and Shelf Life (December 2026) proposes a “physical barrier chemical anchoring” dual inhibition system to address this contradiction, attempting to limit the migration behavior of plasticizers at the material structure level.

Design logic of dual inhibition system

The so-called physical barrier is to construct a barrier structure in the PLA matrix that can hinder the diffusion of small molecules and prolong the diffusion path of plasticizers inside the matrix;

; Chemical anchoring enhances the interaction between plasticizers and polymer chains, reducing their ability to move freely. The synergy between the two aims to “lock” plasticizers inside the matrix without significantly sacrificing material flexibility. This study was conducted by Chunxiu Liu, Jianhong Liu, Chunhui Zhang, Hongyu Gao, and Yubing Dong. The research focuses on the inhibition strategy of PLA plasticizer migration and belongs to the work of packaging material formulation and performance.

The significance of migration control for the packaging materials and polymer additives industry

From the perspective of packaging material application, migration control is directly related to food contact compliance and shelf life performance.

. The migration of plasticizers may not only affect the mechanical properties and heat sealing strength of packaging, but also alter the surface state of the film, thereby affecting subsequent processing such as printing and lamination. The dual inhibition approach proposed in this study provides a structural regulation direction for the formulation design of PLA based food contact packaging: on the one hand, reducing diffusion rate through barrier structure design, and on the other hand, enhancing component retention ability through interface interactions. For the polymer additive industry, this approach suggests that the design of additive systems needs to be considered in conjunction with the matrix structure. For example, in the processing stage, the selection ofprocessing stabilityandantioxidantswill affect the molecular chain state of PLA during extrusion and blown film processes, thereby affecting the formation of matrix barrier structures and the dispersion uniformity of plasticizers; If significant degradation occurs during the processing and the matrix structure defects increase, it may actually provide channels for migration. Therefore, the reasonable combination of antioxidants and stable processing systems is an important prerequisite for the implementation of migration control strategies. In addition, with the expansion of the application of recycled materials in the packaging field, the migration risk of residual additives and degradation products in recycled PLA or mixtures needs more attention. The principle of “structural barrier+interaction anchoring” embodied by the dual inhibition system also has reference value for the design of packaging formulas containing recycled materials, helping to balance flexibility, processability, and safety in food contact scenarios.

Limitations to be noted

This study is a material level suppression strategy, and specific migration amounts, detection methods, and compliance conclusions need to be based on the original data.

; Its applicability under different thickness films and different food simulants conditions still needs further verification.

Information source:Mitigating plasticizer migration in bio-based PLA by constructing a physical barrier-chemical anchoring dual inhibition system， Organized by Herun Chemical.