Extended time–temperature rheology of polyvinyl butyral (PVB)

Abstract

Polyvinyl butyral (PVB), used in safety glass and photovoltaic panels, is commonly described as a complex viscoelastic solid. However, this description is questionable: a viscoelastic solid rheology does not account well for the data obtained at high temperature and the value of the long-time elastic modulus is poorly defined. In this article, an extended rheological study of this polymer in shear geometry has been performed for temperatures ranging between 25°C to 140°C thanks to relaxation and oscillatory experiments. We provide the time-temperature superposition master curve for PVB as well as its time-temperature state diagram. Last, by interconverting the frequency measurements in the time scale and shifting the relaxation modulus through temperature-time superposition, we obtain the evolution of the relaxation modulus as a function of time over 13 orders of magnitude. This curve, well fitted by a generalized Maxwell model with only 10 Maxwell elements, reveals the predominance of the viscous character of PVB at long times with a vanishing long-term elastic modulus.Extended time-temperature rheology of Polyvinyl Butyral (PVB)

Damage Resistance of Kevlar® Fabric, UHMWPE, PVB Multilayers Subjected to Concentrated Drop-Weight Impact

“…Thus, at relatively low strain rate, their behavior is significantly different. It is known that polyethylene experiences a strain hardening at a higher loading rate [ 40 , 41 ], and PVB is a viscoelastic polymer with a strong temperature and load-rate dependence [ 22 , 42 ] too. Experiments to compare these results with ballistic measurements of the same structures are in progress and will be reported elsewhere.…”

Water Clustering in Polyvinyl Butyral (PVB): Evidenced by Diffusion and Sorption Experiments

“…10 The polydispersity index is 1.4, the molar mass is 200 kg mol −1 , and the glass transition temperature is around 25 °C. 11 To better comprehend the link between sorption and polymer chemistry, we further surveyed pure PVB in powder form without the plasticizer molecule. In this case, we procured powder having 8 and 18 wt % VOH from Chang Chun Petrochemicals (CCP).…”

“…The blend further included triethylene glycol di­(2-ethylhexanoate) as a plasticizer molecule in a concentration of about 20% wt . The polydispersity index is 1.4, the molar mass is 200 kg mol –1 , and the glass transition temperature is around 25 °C …”

“…In a previous publication, 11 we have shown that it is possible to estimate the PVB state (glassy, rubbery, and viscous melt) based on characteristic relaxation times, provided that the temperature and time of solicitation are known. Of interest here is t d (T), the characteristic temperature-dependent time required for PVB to transition from the rubbery to the viscous state.…”