Centre for Materials Science Research

Organic Polymer Materials and their properties

Activities in this area include studies in the fields of:

  • Recycling of Thermoplastics
  • Development of novel reactive interfacial modification (coupling agent) systems for fillers
  • Investigation of new sources/types of mineral fillers for plastics
  • Polymer layered silicate nanocomposites based on both thermoplastic and thermosetting polymer matrix materials
  • Controlled release of functional additives from porous particles
  • Photo-active pigments for antimicrobial applications and NOx reduction
  • Dynamic Mechanical Properties of Materials
  • Thermal and Photodegradation of Polymer Materials
  • Thermal and Photostabilisation of Polymer Materials
  • Dye and Pigment Chemistry
  • Radiation Curing and Photoimaging Science
  • Functional Polymer Materials for LED’s, Optical Switching Devices and Sensors
  • Polymer Analysis
  • Food Science, Technology and Manufacturing

The major weakness of particulate filled thermoplastics can be poor mechanical properties relative to an unfilled matrix, this is particularly true of polymers filled with flame retardant fillers that must be present at > 60 % w/w to give the required level of flame retardancy and smoke suppression.  The poor mechanical and melt rheological properties of these materials can be improved by improving the dispersion of filler particles in the matrix and by increasing the strength of adhesion between the filler and matrix.  Dispersion quality can be improved by reducing strength of filler – filler interaction and increasing the wettability of the filler particle by the polymer melt.  The latter can be achieved by covering the filler surface with non - polar species thereby reducing the surface energy such that it is closer to that of the polymer melt.  Improvement in interfacial adhesion can be accomplished via matrix macro-radical addition to double bonds on the surface modifier molecule and/or entrapment within a polymerised/polymerising network of adsorbed surface modifier molecules.  Currently these objectives can be met using organosilanes which are expensive and cannot be used on calcium carbonate and wood particle fillers.  We are working with an industrial partner to develop alternative coupling agent systems that are more cost effective and work well with calcium carbonate and wood particle fillers. 

Alternative mineral fillers for polyethene film antiblocking applications and engineering thermoplastic and elastomer reinforcement are being investigated as part of an industrially funded research project.  One of these minerals is currently used for filtration media and when it is no-longer required for this role it is disposed of in land fill.  Some of the research being carried out is exploring the use of this used filter medium as a filler, therefore adding value to what would otherwise be a waste product and reducing the volume of land fill.

Polymer layered silicate nanocomposites, are just now beginning to become a commercial reality, particularly in the automotive and packaging sectors.  These materials are still nevertheless difficult to form in a reproducible manner due to problems associated with thorough dispersion of the nanoparticles in the polymer matrix.  We are currently conducting studies aimed at understanding the interactions between layered silicates and polymer matrix materials and how these interactions are affected by organic modification of the layered silicate.  One particular study is fundamental in nature and is aimed at probing the latter interactions using flow micro-calorimetry and infrared spectroscopy and the other is being conducted with an industrial partner with the aim of producing an effective reactive intercalation system suitable for polyolefin matrix nanocomposites.