title: Structural mass irregularities and fiber volume influence on morphology and mechanical properties of unsaturated polyester resin in matrix composites.
abstract: This paper presents the comparative results of a current study on unsaturated polyester resin (UPR) matrix composites processed by filament winding method, with cotton spun yarn of different mass irregularities and two different volume fractions. Physical and mechanical properties were measured, namely ultimate stress, stiffness, elongation%. The mechanical properties of the composites increased significantly with the increase in the fiber volume fraction in agreement with the Counto model. Mass irregularities in the yarn structure were quantitatively measured and visualized by scanning electron microscopy (SEM). Mass irregularities cause marked decrease in relative strength about 25% and 33% which increases with fiber volume fraction. Ultimate stress and stiffness increases with fiber volume fraction and is always higher for yarn with less mass irregularities.
authors.affiliation: Applied Chemistry Research Centre, Pakistan Council of Scientific & Industrial Research Laboratories Complex, Karachi 75280, Pakistan.
authors.forename: Khalil
authors.initials: K
authors.lastname: Ahmed
authors.affiliation: Department of Chemistry, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Nasir
authors.affiliation: Department of Chemistry, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Nasreen
authors.initials: N
authors.lastname: Fatima
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Khalid M
authors.initials: KM
authors.lastname: Khan
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Durey N
authors.initials: DN
authors.lastname: Zahra
keywords: Cotton fiber; Mechanical properties; Morphology; Polymeric composite; Structural mass irregularities