Preliminary analysis of the possibility of preparing PVB/IF-WS2 composites. Effect of nanoparticles addition on thermal and rheological behavior of PVB

Danica Simic,Ljubica Totovski,Mirjana Dimic,Dusica Stojanovic,Radoslav Aleksic,Sasa Brzic,Petar Uskokovic

doi:10.5937/str1604015s

Abstract

A possibility of using inorganic fullerene-like tungsten disulfide, IF-WS2, nanoparticles as a filler in poly (vinyl butyral), PVB, for improving its thermal and rheological properties is examined. PVB is a thermoplastic polymer with excellent properties, widely used: in ballistic protection, for protection of safety glass, in metal primers and coatings, temporary binders. Two different molecular weights of PVB were previously examined in this research: Mowital B60H and B75H. Both grades of PVB were dissolved in different solvents: ethanol and 2-propanol. Thin films were prepared by solvent casting technique. The glass transition temperature (Tg) of the tested samples was determined using differential scanning calorimetry (DSC), at three different heating rates (5°C/min, 10°C/min and 20°C/min). After choosing a solvent and PVB grade, IF-WS2 nanoparticles were added to PVB solutions and dispersed by ultrasonic irradiation. Compatibility, i.e. interaction of IF-WS2 with the dissolved PVB was examined by microcalorimetry method. The nanoparticles dispersion and deagglomeration in matrix of PVB was analyzed by scanning electron microscope (SEM). The effect of IF-WS2 on rheological properties of the chosen samples has been examined using Dynamic Mechanical Thermal Analysis (DMTA), observing storage modulus, loss modulus and the loss factor as functions of temperature for the tested composites.

Highlights

INORGANIC fullerene-like nanoparticles of transition-metal dichalogenides, having spherical closed structure, are well known for their excellent mechanical properties
For PVB grades B60H and B75H, for all the three heating rates, registered Tg values, presented in Tables 1 and 2, are much more uniform for the second heating, while for the first heating there is a significant difference between the obtained results
PVB dissolved in ethanol has closer Tg values taken from the first and second heating, for all the three heating rates, i.e. more reproducible and reliable results are obtained for this solvent

Summary

Introduction

INORGANIC fullerene-like nanoparticles of transition-metal dichalogenides, having spherical closed structure, are well known for their excellent mechanical properties They are used for a wide range of applications, including aerospace and automotive technology, in different mechanisms for load bearing and release, for corrosion protection, and as solid lubricants [1]. Thin films were prepared and the glass transition temperature (Tg) of the tested samples was determined using differential scanning calorimetry (DSC), at three different heating rates (5°C/min, 10°C/min and 20°C/min). Microcalorimetry may as well be used to observe the degree of interactions between any different materials In this research, these tests were performed using heat flow calorimeter LKB Bioactivity Monitor 2277. The effect of IF-WS2 on rheological and viscoelastic properties of the chosen samples has been examined using Dynamic Mechanical Thermal Analysis (DMTA). Strain sweeps are oscillatory tests performed at variable amplitudes, while keeping the frequency at constant value (the measuring temperature). The glass transition temperature (Tg), determined by the dynamic mechanical measurements, was estimated as the temperature at which the loss factor, tan (δ) reached its maximum value

Results and discussion

IF-WS2 nanoparticles

Conclusion