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Polímeros

Print version ISSN 0104-1428On-line version ISSN 1678-5169

Abstract

MOREIRA, José C. et al. Influence of temperature, molecular weight, and molecular weight dispersity on the surface tension of PS, PP, and PE: experiments and theoretical analysis. Polímeros [online]. 2003, vol.13, n.1, pp.45-53. ISSN 0104-1428.  http://dx.doi.org/10.1590/S0104-14282003000100010.

In this work, the influence of temperature, molecular weight (n) and molecular weight dispersity (MWD) on the surface tension of polystyrene (PS) was evaluated using the pendant drop method. The influence of temperature on the surface tension of isotatic polypropylene (i-PP) and of linear low density polyethylene (LLDPE) was also studied here. Patterson-Rastogi and Dee and Sauer theories were used in conjunction with the Flory, Orwoll, and Vrij (FOV) equation of state to predict surface tension (g) using bulk pressure-volume-temperature (PVT) data. Both theories predicted that surface tension decreases linearly with increasing temperatures and increases with molecular weight corroborating the experimental data. However, both theories underestimated the entropy change of surface formation per unit area at constant volume for low molecular weight and polydisperse systems and underestimated the effect of molecular weight dispersity on surface tension.

Keywords : Surface tension; polystyrene; polyethylene; polypropylene.

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