TPV Research: Nonlinear Polymer Behavior
Fig. Macro-scale version of TPV microstructure, particle in matrix
The Problem
TPV (Thermoplastic Vulcanizates) is a high-performance rubber-plastic polymer widely used in seals, gaskets, and weather strips.
However, the relationship between its microstructure and mechanical behavior is not well understood, particularly the deformation mechanisms. This project was set to investigate how the spatial arrangement of particles within the stiff matrix drives local deformation mechanisms.
To study this, I needed a repeatable, controlled way to fabricate and test samples of TPV.
Fig. 3D STEP files for Polyjet Printing
The Approach
Geometry Generation Pipeline
Developed a Python script to parametrically generate periodic samples with tunable parameters: volume fraction, particle size, arrangement, and randomness
Generated 8 unique patterns
Exported multi-material STEP files for direct PolyJet 3D printing
Fig. Plane-strain compression fixture
Fixture Design
Designed and fabricated a custom plane-strain compression fixture
Modeled custom 3D printed parts, laser-cut acrylic platens, and ordered custom steel standoffs
Fig. Plane-strain compression fixture
Physical Testing
Tested 12 specimens on a Zwick-Roell universal testing machine to 20% compressive strain
Tested specimens in multiple loading orientations to probe anisotropy
Conducted post processing and data analysis
The Result & Impact
Showed particle arrangement drives stiffness more than size distribution.
Single-grid packing was ~2.5× stiffer than staggered at identical volume fraction
Demonstrated that scaling particles down 0.5× at constant Vf increases stiffness and reduces anisotropy
Built a fully reusable geometry pipeline extensible to elliptical and rectangular particle shapes
Established that deformation localizes through the thinnest matrix ligaments.
Path of least resistance governs local failure across all cases