Design Principles for Information‐Efficient Multimodal Analytical Workflows for Nondestructive Quality Assessment of Polypropylene After Accelerated Weathering

The transition toward a circular plastics economy requires rapid and reliable quality assessment of recycled materials; however, information‐efficient nondestructive workflows require further development. A strategy is proposed for designing multimodal workflows for nondestructive quality assessment within a controlled polypropylene (PP) material library. A systematically designed platform comprising commercial virgin PP grades, one post‐industrial recycled PP grade, and six recycled/virgin blends, all evaluated after accelerated weathering, is characterized using complementary nondestructive analytical techniques, including X‐ray diffraction (XRD), Raman, infrared, and near‐infrared spectroscopy, and optical microscopy, together with destructive Charpy impact testing. An integrated data‐driven framework evaluates not only assessment performance but also the incremental contribution of individual modalities. The multimodal workflow estimates impact strength over a broad range of material qualities and reveals a performance hierarchy among alternative analytical workflows. Within the sequential workflow analysis, combining XRD with Raman peak descriptors and a Raman‐spectrum model provides the greatest improvement, whereas subsequent measurements yield smaller gains. Direct comparisons with infrared and near‐infrared alternatives show that the observed advantage depends on the feature representation used. The framework provides a basis for rational measurement selection, while its applicability to heterogeneous post‐consumer recycled PP requires further validation.