Nano SiO2 and terminal carboxyl polyesterco modified epoxy composites

DOI:	10.11809/bqzbgcxb2025.01.040
Keywords:	nano SiO2; terminal carboxyl polyester; epoxy resin; KH 550; mechanical properties
Abstract:	For the purpose of toughening brittle epoxy resin which was used as composite matrices for seawater pipeline rehabilitation, the effects of co modification of terminal carboxyl polybutylene adipate (CTPBA) and nano SiO2 on the mechanical properties, adhesive properties, thermodynamic properties and moisture resistance of epoxy resin were systematically studied. The modification of nano SiO2 by silane coupling agent KH 550 can significantly improve the mechanical properties and adhesive properties of epoxy resin materials. The tensile shear strength, tensile strength and impact strength of the composites increased first and then decreased with the increase of the amount of modified nano SiO2, reaching the maximum value at 2 phr, which increased by 6.96%, 56.62% and 68.22%, respectively, compared with the non addition amount. SEM analysis of impact section morphology showed that the toughening mechanism was the shear deformation caused by CTPBA and the second phase toughening caused by nano SiO2. The addition of nano SiO2 can shorten the gel time, improve the peel strength and heat resistance of the system, and reduce the glass transition temperature. The water absorption rate of the composites decreased first and then increased with the increase of the amount of modified nano SiO2 added, reaching the minimum value at 2 phr, and the moisture resistance was the best.
Issue:	Vol. 46 No. 1 (2025)
Published:	2025-01-31
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