Study On The Relationship Between Super Toughening Mechanism For Multiphase Polymer Materials And Sub-cluster Scale

In this work, a Sub-cluster scale model of super toughening mechanism for multiphase polymer was set up on the basis of the Sub-cluster statistic theory, aiming at revealing the relationship between the mechanical properties and the morphology of polymer blends. It was predicted from Sub-cluster scale theory that the relationship between the Sub-cluster scale and the mechanical properties of polymer blends should be categorized into two types; (1) The mechanical properties increase with the increasing of the uniformity of the rubber particle size. The mechanical properties vary linearly with the Sub-cluster scale ln(R₁ ? R₂) with a negative slope. The dispersing of rubber particles follows a principle of maximum activation energy. (2) The mechanical properties should increase with the uniformity of distribution of the rubber particle size. The mechanical properties vary linearly with the Sub-cluster scale ln(R₁ ? R₂) with a positive slope. The dispersing of rubber particles follows a principle of minimum activation energy. It was also predicted that the Sub-cluster scale InR₁, and lnR₂ should be related linearly to fracture work and yield work, respectively.In the light of Sub-cluster scale theory, two toughened Nylon 6 systems were designed; (1) Nylon 6 and poly ( methyl methacylate-co-butyl acrylic) " core-shell " type impact modifier (EXL2330) were compatibilized by diglycidyl ether of bisphenol-A (DGEBA) epoxy resin. The adhesion at the interface of Nylon 6 and EXL2330, and the dispersity of EXL2330 in Nylon 6 matrix were improved via the reaction among the epoxy groups on DGEBA and end amine groups on Nylon 6, a.nd hydrogen bond between —OH group on DGEBA and carbonyl oxygen on the PM-MA shell of EXL2330. As a result, the system obtained a super toughness. (2) Nylon 6 and its toughener . methylene-vinyl acetate copolymer (EVA) were compatibilized by methylene-acrylic acid copolymer (Nucrel) or methylene-acrylic acid-vinyl acetate copolymer (Elvaloy). The adhesion at the interface of Nylon 6 and EVA, and the dispersity of EVA in Nylon 6 matrix were improved, and EVA particle size was decreased via the miscibility of Nucrel or Elvaloy with EVA, and the interaction among amide groups on Nylon 6, and carboxy on Nucrel or Elvaloy. For this reason, the impact strength of the toughening system was improved significantly. It was also found that Nucrel has a better compatibilizing effect on Nylon 6/EVA blends, due to its higher content of acrylic acid functional group.The analysis of the data shows that Nylon 6/EXL2330/DGEBA blend system provides the largest Sub-cluster scale and a minimum activation energy of particle size distribution, whereas, Nylon 6/EVA/Nucrel (or Elvaloy) blend system provides the smallest scale and a maximum acti-...