Study of thermal aging effect on optical properties of some polymer blends

Dissertant

Furayyih, Marwah Rahim

Thesis advisor

Hamid, Nahida J.

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2010

English Abstract

With study of the blending ratio effect on the optical properties of the polymer systems involved (PMMA, PC, and PS), binary blends (PMMA / PC, PMMA / PS, and PC / PS), and ternary blends (PMMA/PC/PS) at different concentrations.

The second stage was concerned with study of thermal aging effect on the above photopolymers, and the polymer system of best optical properties.

The samples were casted as films from the photopolymer stated above and the blends as a binary and ternary blend at different concentration.

These prepared polymer systems were evaluated spectrophotometricaly for selecting the polymer systems of the best optical properties.

It was found that 50 % PMMA / 50 %PC binary blend has the best optical properties.

The results proved that its energy gap was (2.5eV), which was the lowest of all polymer system involved.

The photopolymers above and 50 % PMMA / 50 % PC binary blend were subjected to thermal aging within range of (50-250°C) for (2hr) to study the effect of thermal aging on their optical properties.

The absorption spectra of the thermally aged polymer systems showed heating induced absorption changes in the wavelength range, which depends on the polymer type and polymer blend.

The thermal degradation caused increment in the absorption of degraded samples.

The increment depended on polymer type and polymer blend, especially at 250°C in the thermally aged PS samples (2.3Ev).

Decreasing in absorption was found for cases in which, thermal degradation caused surface damage i.e.

crazes or cracks formation.

The optical energy gap and reach energy were calculated the absorption spectra before and after thermal aging to the polymer systems involved.

The results showed nonlinear relationship between the optical constants and blend ratio, it was attributed to their immiscibility.

The nonlinear relationships between the optical constant of the thermal aged polymer systems and polymer blend with the heating temperature was attributed to the unsystematic thermal degradation induced by heating, it was found PMMA and PC have the best heat resistances in comparison with the polymer involved.

Morphological investigations for the surface damages (crazes, and cracks) caused were performed by optical microscope .It was found that the thermal degradation could easily lead to some mechanical surface damage.

FTIR spectroscopy was carried out for polymer systems before and after thermal aging to identify the region of the main characteristic bands and its results were investigated.

Main Subjects

Chemistry

Topics

• Optical properties
• Chemical reactions

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305139