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Abstract

Thermosetting resins have been one of the most important polymeric materials for modern industries owing to their outstanding integrated properties. However, their brittleness and low impact strength greatly limit their applications in cutting-edge fields, so toughening of thermosetting resins has been an important issue for investigations. At present, 4, 4’-bismaleimidophenyl methane (BDM)/2, 2’-diallylbisphenol A (DBA) and epoxy resin are two typical thermosetting resins, and have wide and great applications, so they are selected as the model for toughening in this thesis. The aim of this thesis is to set up new toughening theory and technology on the base of keeping excellent performances of original thermosetting resins.Hollow silicon tubes (HST) have large specific surface areas, hollow structures and high heat conductivity, showing great potential as catalysts, storage devices, reinforcements, etc. But their application in modification of thermosetting resins is seldom reported.In order to enhance the compatibility and improve interfacial adhesion between HST and the matrix resin, HST was modified byγ-Aminopropyl triethoxy silane (KH550) to get modified HST (mHST). Based on this, three composites, mHST/BDM/ DBA, HST/EP and mHST/EP composites, were successfully prepared, and structure and typical performances (toughness, mechanical properties, thermal properties, dielectric properties and water absorptions) of these composites were systematically investigated.Results show that the impact strength of mHST/BDM/DBA composite with 0.5wt% mHST is about 2.2 times that of BDM/DBA resin. In addition, compared with BDM/DBA resin, the composites exhibit lower and stable dielectric constant, better frequency stability of dielectric loss, significantly improved flame retardancy, and similarly outstanding thermal resistance. Compared with BDM/DBA resin, mHST-1.0/ BDM/DBA composite has 24 or 20% reduction in the peak heat release rate (PHRR) or total heat release (THR), respectively, while its value of tign lengthens by 18s.The reasons behind these attractive integrated properties were discussed from the view of structure-property relationship.In order to further evaluate the interface effect on the properties of composites, HST-s/EP and mHST-r/EP composites were comparatively studied. Results show that both HST and mHST can improve the integrated performance of composites such as toughness, thermal stability and dielectric properties. Because mHST has better interface bond with EP resin, mHST-r/EP composites have better comprehensive performance than HST-s/EP composites’.

Silicon Tubes Modified Thermosetting Resins

Abstract

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