Reactive modification of Pbt with applications in low density extrusion foaming

Document Type

Article

Publication Date

1-1-2007

Abstract

By contrast to polyethylene terephthalate (PET), extrusion foaming of polybutylene terephthalate (PBT) to medium-low densities has been seldom reported in the literature. In this study, a commercial linear PBT resin was reactively modified in a batch mixer to a branched structure with a higher molecular weight (MW) and a broader molecular weight distribution (MWD) as evidenced by rheological analysis. Chain branching was also accomplished by single screw extrusion, where the competing degradation reaction needed to be taken into account. Optimization of the extrusion operational conditions, which also involved the use of suitable consititutive equations, led to the production of a branched resin with viscoelastic characteristics suitable for low density extrusion foaming by injection of physical blowing agents (PBA). The branched product made under the optimized conditions showed good foamability. The effect of pressure drop rate on cell nucleation rate and the effect of the crystallization rate on cell density and cell morphology are examined. © 2007 Society of Plastics Engineers.

Identifier

33947599575 (Scopus)

Publication Title

Polymer Engineering and Science

External Full Text Location

https://doi.org/10.1002/pen.20699

e-ISSN

15482634

ISSN

00323888

First Page

244

Last Page

253

Issue

3

Volume

47

This document is currently not available here.

Share

COinS