The Effect of Compatibilisation for Blends of Nylon 6 or Polybutylene Terephthalate (PBT) with Metallocene Linear Low-Density Pblyethylenes

摘要

Polymer blends of polyamides and polyethylenes are immiscible and highly incompatible. These blends are characterised by high interfacial tension, a two-phase morphology and poor physical characteristics due to reduced interaction across the phase boundaries. PBT like many other polymers is a brittle material with a high modulus value and is not suitable for certain applications. Blending and compatibilising with an incompatible polyethylene phase may improve these properties. The compatibilising agent, maleic anhydride-grafted-LLDPE, is physically miscible with the polyethylene phase and has a chemical functionality with the polyamide phase and the carboxylic and hydroxyl end groups of the PBT phase. The use of a new generation mLLDPE (ENGAGE~(TM) by Dupont) was also studied to investigate its suitability as a modifier for the polyamide and polyester grades. The influence of the percentage composition of the mLLDPE and the effect of the addition of the compatibiliser were both investigated for their effect on the mechanical properties. They were both shown to significantly improve the modulus and elongation with only a slight reduction in the impact properties of the final product.