The Weathering Study of PC/ASA Alloy For Automotive Exterior Applications

Year 2018, Volume: 5 Issue: 1, 61 - 72, 01.09.2017

Sinan Öztürk

https://doi.org/10.18596/jotcsa.288358

Cited By: 2

Abstract

Polycarbonates (PC) are used in automotive industry due to
high physical and mechanical properties like high impact resistance and
ductility. Polycarbonates are blended with ABS (Acrylonitrile-Butadiene-Styrene)
and ASA (Acrylonitrile-Styrene-Acrylate) terpolymers for interior and exterior
applications of automotive components to achieve good physical and mechanical
properties. Other reason for choosing such alloys for interior applications is
the IZOD impact resistance requirement higher than 40kJ/m². Recently,
grades of PC/ASA with UV stabilized are developed for non-painted exterior
applications.  

The aim of our study is to investigate whether new developed
PC/ASA could be chosen for exterior applications of automotive industry. In
this study, the samples are prepared from injection molding and the weathering
performance of PC/ASA was tested by a weather-o-meter for 1500h at a total of
1890 kJ/m² at 340nm with a cut-off filter at λ<290nm. The results
are evaluated by FT-IR, DSC, TGA and SEM. It has been observed that UV
degradation of PC/ASA leads to several major changes in its IR spectrum like
broad bands occurred in the hydroxyl region around 3300cm^-1, and
carbonyl stretching region increased around 1728 cm^-1. The main
degradations were based on photo-oxidation and photo-Fries rearrangement of PC.
In our study, the photo-oxidation was followed by the color shift to yellowing
of the polymer.

Keywords

PC/ASA Alloy, weathering, photo-oxidative degradation, automotive exterior applications

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