Effect of Blending Temperature on the Characteristics of Modified Polyacrylonitrie Homopolymer

Ahmad Fauzi Ismaila,Azeman Mustafa,Muhammad Syukri Abd Rahaman

doi:10.5539/mas.v2n2p131

Abstract

This paper examines the modification of polyacrylonitrile (PAN) homopolymer by a blending technique. The discussion on this modified PAN fiber involves the comparison a new concept of comonomer attachment compared to the conventional method. The PAN homopolymer and comonomers (i.e. itaconic acid (IA) and methylacrylate (MA)) were dissolved in dimethylformamide (DMF) at two different temperatures; 70°C (Type 1) and ambient temperature (Type 2). These fibers were fabricated using a simple the dry/wet spinning process before subjected to a stabilization process. FTIR result shows that the peaks (around 1600cm-1) indicated that the comonomers in Type 1 fiber were attached to the PAN homopolymer backbone during the dope preparation step. However for Type 2 fibers, the comonomers were only attached to the PAN homopolymer backbone during the stabilization process. Type 1 fibers also have higher weight loss and faster stabilization compared to Type 2 fibers. Therefore, the blending process at heat temperature of 70ºC is claimed as the technique that can modify the PAN homopolymer and make the stabilization process of PAN fibers faster.

Highlights

Polyacrylonitrile (PAN) is a polymer with carbon chain connected to one another
Carbanion is a condition which the carbon atom bears a negative charge which help to initiate the reaction of comonomers and polyacrylonitrile (Wade, 1999)
The essential requirement of the comonomer was proven when the cyclization reaction became faster in stabilization process

Summary

Introduction

Polyacrylonitrile (PAN) is a polymer with carbon chain connected to one another. Polyacrylonitrile is hard, horny, relatively insoluble, and a high-melting material (Schwartz, 2002). Manufacturing of PAB fibers with high tensile and high modulus is of significant interest In terms of processing path, Liu et al (1994) has listed three main steps in converting PAN based fibers to carbon fibers. They are: (1) Oxidative stabilization, which form ladder structures to enable them to undergo processing at higher temperatures; (2) High temperature carbonization, (i.e. up to 1600 ° C) to evolve non-carbon atoms and yield a turbostatic structure; (3) Further heating, up to 2000 °C to improve the orientation of the basal planes and the stiffness of fibers, which is known as graphitization

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