Study On Preparation And Properties Of Hyperbranched-Polyester/Epoxy Resin Composite

In this paper, several kinds of hyperbranched polyester(HBP) modifiers of epoxy resin have been synthesized. Using these materials the composites of HBP /epoxy resin were prepared. The morphology of impact section, mechanical properties and heat stability of composites were studied by using of bending test, impact test and with the application of DSC, TG, SEM. Besides, the synthesize way of modifiers and the influence of HBP to the structure and mechanics properties of composites were explored as well. The detailed results were as follows ( 1 )three-dimensional structure of hyperbranched polyester have great influence on the properties of composite. It is helpful to improve the mechanics properties of composite by using polyethylene glycol as kernel or acetic ended of molecule surface.( 2 ) A key issue when using HBP tougheners is the possibility of phase separation. The phase separation process depend on the chemical nature of the components, and is kinetically controlled by the curing advancement. In order to ensure that it occurs after final resin flow. Thus, the structures of HBP need to be tailed. This paper, Selecting hyperbranched polyester HB30 as the investigator, two-phase structural composite of HBP/epoxy resin has been prepared by modifying the surface structure through ester reaction. After modification, the impact strength of composite improved from 8.4 kJ/m2 to 18.2 kJ/m2 with 15% weight content. The results of SEM showed that: the diameter of HBP particle in matrix forms uniform distribution, which is different with the bimodal distribution for line modifier in matrix.(3)Though the co-polymerization between HBP and amino- caprolactam, The plastically ability of HBP for epoxy resin can be improved. The impact strength increased to 20.4 kJ/m2 with 7% weight content of copolymer in the system of epoxy resin. Furthermore, two different methods were adopted to make the copolymer react with butyl acrylate, so as to prepare the composite of epoxy resin with different structure. Analysis methods such as SEM, DSC, TG were applied to characterize the composites.