Multifaceted Evaluation of Changes in Physical Properties of Recycled Plastics by Advanced Recycling Process and Influencing Microstructural Changes (Part 3): Example of Application to Recycled Polypropylene Derived from Automotive Offcuts without Filler

User Benefits

- Evaluation of changes in the microscopic physical structures in plastic during molding is possible by multifaceted measurements using general-purpose instruments. - It is possible to understand the physical properties of plastics and the factors that influence those properties.

Introduction

In the previous Application News article “Multifaceted Evaluation of Changes in Physical Properties of Recycled Plastics by Advanced Recycling Process and Influencing Microstructural Changes (Part 2),” we found that the microscopic physical structures of simulated degraded polypropylene (PP) were controlled by applying the new-developed advanced recycling process, and as a result, the strain at break and the impact property of the plastic were improved. We also showed that a multifaceted evaluation combining the elastic modulus, indentation hardness (H_IT), crystallization start temperature, proportion of the helical structure, and the orientation in the micro region is an effective approach for understanding changes in microscopic physical structures. In this article, we report the results of a study to determine whether this multifaceted evaluation approach is also effective for understanding the microscopic physical structures in actual recycled plastic, based on the practical application of the social implementation of recycled plastics. In this connection, in the automotive industry, active study on implementation of plastic recycling is also underway globally, beginning with a draft of regulations released by European Commission (EC) in July 2023. Based on this trend, recycled PP derived from automotive offcuts without fillers was used as the sample material in this study.

July 22, 2025 GMT