Effects of butyl acrylate modified polypropylene on structural and thermal properties of foamed polypropylene

Abstract

In this work, the melt strength of PP matrix was reinforced by crosslinking-modified PP (CM-PP) which was yielded by peroxide-initiated crosslinking of linear PP with butyl acrylate (BA). The nano-silica aerogel (nano-SiO 2 ) worked as a nucleating agent for foaming. The effects of CM-PP with the various contents of BA on the foaming behavior and thermal property of PP were studied by measurements of density, thermal conductivity, Vicat softening temperature and SEM. The results showed that the foamed PP got the best properties when the crosslinking PP modified with the weight ratio of butyl acrylate was 10 wt %. The density of the obtained foamed PP with uniform closed cells was as low as 0.23 g/cm 3 , the thermal conductivity was 0.044 W/(m K), and the Vicat softening temperature was 120 8C.

Scalable Fabrication of Thermally Insulating Mechanically Resilient Hierarchically Porous Polymer Foams

“…The thermal conductivity of Foam-A, Foam-B, and the bulk material is tested under ambient conditions and the results are presented in Figure a. Foam-A shows a thermal conductivity of 0.029 W m –1 K –1 for air, and Foam-B exhibits a significantly higher thermal conductivity of 0.04 W m –1 K –1 , which is similar to the thermal conductivity of PP-based foams reported in other studies. − The low thermal conductivity of Foam-A is ascribed to the average pore diameter of the nanoporous cell walls (25.2 nm) being smaller than the mean free path of air (ca. 70 nm under ambient conditions), effectively reducing air conductivity contributions to the thermal conductivity, which typically account for 60–70% of the thermal conductivity in foams .…”