A study of Silicate-Reinforced Polyvinyl Butyral Composites

Introduction

Polyvinyl butyral (PVB) is a thermoplastic terpolymer known for its excellent optical clarity and strong adhesion to glass, which is due to its vinyl alcohol monomer units. Due to the latter characteristics, PVB is used as interlayer between two silicate glass sheets in laminated safety glass. Other interesting combinations of PVB and silicates correspond to composites based on PVB matrices and silicate dispersions [1]; we consider herein a range of properties for silicate dispersions in the form of fibers, flakes, or powders.

Methods

Silicate particles of varying sizes and morphology (flakes, fibers, nanoparticles), silane functionalization, and different loading levels (5%, 10%, 15% w/w) were incorporated into the PVB matrix using a Brabender internal mixer (150°C, 40 rpm, 5 min). The effects of each reinforcement were evaluated via optical microscopy, TGA, mechanical testing (tensile and impact resistance), light transmittance, and water absorption tests.

Results

All silicate reinforcements enhanced the thermal stability of PVB. Fumed silica nanoparticles not only increased tensile strength and maintained optical transparency but also reduced water absorption. In contrast, glass fibers primarily contributed to enhanced impact resistance.

Conclusions

Low-aspect-ratio silicate particles are appropriate fillers/modifiers for PVB. In addition, PVB is a good polymeric matrix material for composites with high aspect ratio silicate particles.

Conflict of interest

The authors declare no conflicts of interest.

Acknowledgments

We thank GlassFlakes Co., Ltd (UK) and NEOTEX S.A. (Greece) for supplying samples and Mr. Christophoros Razos for his assistance in the experimental work.

References

1. Miller, A.C.; Berg, J.C. Effect of Silane Coupling Agent Adsorbate Structure on Adhesion Performance with a Polymeric Matrix. Composites Part A: Applied Science and Manufacturing 2003, 34, 327–332.