Surface Deformations of Polymers induced by a Pendulum Scratch Machine

Authors

  • Tanveer Iqbal UET Lahore
  • Saima Yasin University of Engineering & Technology, KSK Campus, Lahore
  • Brian J Briscoe Imperial College London
  • Muhammad Zafar University of Engineering & Technology, Lahore
  • Naveed Ramzan University of Engineering & Technology, Lahore

Keywords:

Deformations, Polymers, Scratching, Ductile, Brittle

Abstract

The experimental study describes the surface deformations of polymers produced through penetration depth dependent scratches produced under different applied normal loads and using rigid conical indenters. The surface deformation of the scratched polymers was determined using an SEM (scanning electron microscope). The deformation mechanisms were observed to be manipulated by imposed experimental conditions; such as the normal load, the contact angle, the nominal scratching velocity and the temperature. The polymers are seen to be deformed by ironing, elastic, viscoelastic-plastic ploughing and brittle mechanisms. Along with these surface damages a fibrillation of semicrystalline polymers is also reported when the polymeric surfaces were subjected to most severe contact conditions during scratching.

Author Biography

Tanveer Iqbal, UET Lahore

Ever since my early days at school, I used to enquire from my science teachers about nature of surfaces. “God made the solids – but surfaces were the work of devil†as quoted by Wolfgang Pauli. I used to ask myself questions like: “Why some of the surfaces are hard while others soft? “How a surface changes from smooth to rough with usage? I developed a basic strength for the understanding these questions studying chemical engineering at undergraduate level. My final year project on quality control of paints, where I first time came across terms like mar resistance and surface deformation, proved nothing but a catalyst to enhance my desire to study surfaces. I worked on surface mechanical characteristics of polymers with Prof. Brian J. Briscoe at Imperial College London. My principal area of research was the surface mechanical characterization and tribological studies of polymers and their composites at the micro as well as nano scales. In particular, I have worked on the surface mechanical properties based on the indentation and the scratching response of amorphous and semicrystalline polymeric surfaces and their composites. Surface deformation mechanisms and hardness determines product life and usage and hence plays a vital role in material selection and design. I have developed “hands-on†technical expertise in the following experimental techniques: Nanoindentation Hardness, Scratch Hardness & Deformation Characterization, Scanning Electron Microscope (SEM), Differential Scanning Calorimetry (DSC), Tensile and Compression Testing, Polymer Modifications and Characterizations and Rheology of suspensions. In future, my aim is to work in different research areas of Chemical Engineering mainly relating to material surface characterization. In particular I would prefer working on the following research areas: Morphology of polymeric surfaces, Nanoindentation and Nanoscratching (hardness and deformation) response of material surfaces, Atomic Force Microscopy (AFM): Molecular and Surface Interactions, Human skin friction and deformation mechanisms, Friction and losses reduction in piping flow systems, Solvent and Gas Sorption in polymers, Wear of material surfaces and Boundary Lubrication. My short term goals include the construction of scratch deformation maps of fibre oriented polymer composites and liquid crystalline polymers (LCPs) using scratching conditions and deformation processes from SEM images of scratched polymeric surfaces. The main objective will be to formulate a general strategy for constructing scratch deformation maps of composites and LCPs. These maps will possibly contains data ranging scratching velocity, normal loads, cone angle of indenter, coefficient of friction, scratch hardness, fibre loadings and damage modes of polymeric surfaces. My long time goals are to study the morphological characteristics of polymers and their effects upon surface properties. This might include the use of X-ray, transmission electron microscope (TEM) and neutron scattering techniques although the precedents have not been clearly established. The nanoindentation technique would provide a convenient means to understand morphological description of the polymeric surfaces. Environmental factors like solvent plasticization, thermal and mechanical disruptions severely degrade the polymeric materials. An experimental account to investigate the environmental impacts on polymeric materials is a future goal. Finally, the subsurface damages in the deformed polymeric surfaces may be a practically significant aspect yet to be usefully explored. In summary the future would yield opportunities to examine and rationalise the value of small scale indentation and scratching in the examination and optimisation of the surface and near surface morphology of polymers.

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Published

2012-06-21

How to Cite

Iqbal, T., Yasin, S., Briscoe, B. J., Zafar, M., & Ramzan, N. (2012). Surface Deformations of Polymers induced by a Pendulum Scratch Machine. Journal of the Pakistan Institute of Chemical Engineers, 40(1), 43–49. Retrieved from http://piche.org.pk/journal/index.php/jpiche/article/view/67

Issue

Vol. 40 No. 1 (2012): Journal of the Pakistan Institute of Chemical Engineers

Section

Articles

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