POSS-polyurethane prepolymer strengthened and toughened CF/epoxy resin composites for room and simulated Arctic ambient temperature

• Published in: Polymer (Guilford) 2024-02, Vol.294, p.126692, Article 126692
• Main Authors: Liu, Hailong, Liu, Ming, Zhang, Pengbo, Xue, Kangle, Yao, Tongjie, Liu, Li, Huang, Yudong
• Format: Article
• Language: English
• Subjects: Epoxy resin and CFRPs; Room-temperature and low-temperature; Synergistic strengthening and toughening
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2024.126692

As an important material candidate for automotive, aviation, and aerospace, the wide application of carbon fiber-reinforced epoxy resin composites (CFRPs) was important. However, restricted by the low toughness. Herein, octaaminopropyl cage polysilsesquioxane-polyurethane prepolymer (POSS-PU) was synthesized by in-situ polymerization of PU on the POSS, and then employed as the modifier for epoxy resin (EP). Compared to pristine EP, the toughness of the 7.5 wt% POSS0.5-PU/EP was increased by 115.3 % without compromising the tensile strength and Tg. The unnotched impact strength, interlaminar shear strength (ILSS), and flexural strength of the CFRPs prepared from the modified EP were increased by 73.5 %, 7.5 %, and 42.4 %, compared to CF/EP. Additionally, the mechanical properties of CFRPs maintained a substantial improvement under low-temperature, and the CF/7.5 wt% POSS0.5-PU/EP was increased by 72.9 % (impact strength) and 21.7 % (ILSS), compared to those of CF/EP. Compared to the improvement in the toughness of CFRPs at room temperature, the retention rate of toughness enhancement at low temperature was approximately 100 %. CFRPs prepared by POSSx-PU/EP offered outstanding mechanical properties and hence showed great potential for future industrial applications. [Display omitted] •POSS-PU was prepared by in-situ polymerization, and uniformly dispersed in EP by physical blending.•POSS-PU greatly improved the toughness of the EP (115.3 %) without sacrificing strength and Tg.•Compared to CF/EP, ILSS and impact strength of CF/7.5 wt% POSS0.5-PU/EP increased by 7.5 % and 73.5 %.•CF/7.5 wt% POSS0.5-PU/EP possessed the most outstanding cryogenic strength and toughness.•POSSx-PU/EP has excellent processability since its low consistency coefficient.