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This study focuses on the development of environmentally sustainable polypropylene (PP)-based composites with the potential for biodegradability by incorporating cellulose and the oligomeric siloxane ES-40. Targeting industrial applications such as fused deposition modeling (FDM) 3D printing, ES-40 was employed as a precursor for the in situ formation of silica particles via hydrolytic polycondensation (HPC). Two HPC approaches were investigated: a preliminary reaction in a mixture of cellulose, ethanol, and water, and a direct reaction within the molten PP matrix. The composites were thoroughly characterized using rotational rheometry, optical microscopy, differential scanning calorimetry, and dynamic mechanical analysis. Both methods resulted in composites with markedly reduced crystallinity and shrinkage compared to neat PP, with the lowest shrinkage observed in blends prepared directly in the extruder. The inclusion of cellulose not only enhances the environmental profile of these composites but also paves the way for the development of PP materials with improved biodegradability, highlighting the potential of this technique for fabricating more amorphous composites from crystalline or semi-crystalline polymers for enhancing the quality and dimensional stability of FDM-printed materials.
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This content will become publicly available on April 1, 2027
Robust and Reversible Thermofluorescence in Solvent‐Free Thermoplastic Polyurethane Composites
Abstract Thermofluorescent materials, whose emission behavior can be modulated in response to temperature changes, offer a compelling platform for studying dynamic heat flow and developing smart materials for various advanced applications. To address the issues of fabrication complexity and poor robustness in existing systems, an efficient, solvent‐free blending method is developed to prepare thermofluorescent polymer composites by incorporating indenoquinacridone (IQA) dye into thermoplastic polyurethane (TPU) matrix. The thermofluorescent mechanism arises from a temperature‐sensitive transition between aggregated and dissociated states of IQA, regulated by competing hydrogen bonds from the TPU matrix. This reversible, noncovalent mechanism enables high‐contrast optical signals while maintaining excellent durability and UV resistance—performance unmatched by other organic thermochromic or thermofluorescent dyes. The intrinsic robustness of IQA allows it to endure high‐temperature processing methods such as extrusion, injection molding, and fused deposition modeling (FDM) 3D printing. FDM‐printed cuboids exhibit clear optical responses to temperature change, demonstrating real‐time visualization of heat conduction in complex objects. The integration of robust thermofluorescence with favorable mechanical and processing properties in these composites paves the way for scalable applications in thermal imaging, smart materials, and temperature‐responsive devices.
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- Award ID(s):
- 2348611
- PAR ID:
- 10694480
- Publisher / Repository:
- Wiley-VCH GmbH
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 36
- Issue:
- 29
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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