A novel thermosetting resin system for superabrasives based on novolak and bismaleimide （BMI） was developed. The novolak resin was allylated and then copolymerized with BMI. The structure of allyl novolak and reacti...A novel thermosetting resin system for superabrasives based on novolak and bismaleimide （BMI） was developed. The novolak resin was allylated and then copolymerized with BMI. The structure of allyl novolak and reaction mechanism were analyzed by FFIR. Thermal and mechanical properties were characterized by using com- prehensive thermal analyzer （DSC-TG） and strength tester, respectively. The results showed that high molecular weight of novolak was advantageous for heat-resistance, but was unfavorable for the bending strength. High allyl content improved the heat-resistance but lowered the bending strength. When the molecular weight of novolak was 450 and allyl content was 50%, the best resin system with good heat-resistance and bending strength was obtained. It was suitable for the manufacturing of superabrasive tools.展开更多
Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified dip...Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerize and modify once more. The system was applied in composites. Their properties were investigated and found that they met the requirements as a heat-resisting adhesive.展开更多
This article describes the efforts that led to the development of surface-loaded preforms that may be used to significantly improve the compression-after-impact strength of high-temperature composites and correspondin...This article describes the efforts that led to the development of surface-loaded preforms that may be used to significantly improve the compression-after-impact strength of high-temperature composites and correspondingly to dramatically reduce the area of damage because of impact.Moreover,by matching the toughening polymer surface-loaded and design of the surface pattern,in-plane mechanical properties are unaffected or even improved over laminates made from the identical materials.The proprietary preforms,so-called ESTM-Fabrics,may be handled and infused with the high-temperature RTMable resins such as bismaleimide and polyimide in exactly the same manner as traditional fabrics without surface modification.The RTM conditions for the preform-based toughening is fully compatible with the traditional process procedure,making the technology cost-effective in production.This technology represents a key enabler for the use of low-cost RTM processes for high-temperature resins to supplant prepreg as the building-block material of choice for aeronautical composite structures.展开更多
文摘A novel thermosetting resin system for superabrasives based on novolak and bismaleimide （BMI） was developed. The novolak resin was allylated and then copolymerized with BMI. The structure of allyl novolak and reaction mechanism were analyzed by FFIR. Thermal and mechanical properties were characterized by using com- prehensive thermal analyzer （DSC-TG） and strength tester, respectively. The results showed that high molecular weight of novolak was advantageous for heat-resistance, but was unfavorable for the bending strength. High allyl content improved the heat-resistance but lowered the bending strength. When the molecular weight of novolak was 450 and allyl content was 50%, the best resin system with good heat-resistance and bending strength was obtained. It was suitable for the manufacturing of superabrasive tools.
文摘Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerize and modify once more. The system was applied in composites. Their properties were investigated and found that they met the requirements as a heat-resisting adhesive.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB631100)
文摘This article describes the efforts that led to the development of surface-loaded preforms that may be used to significantly improve the compression-after-impact strength of high-temperature composites and correspondingly to dramatically reduce the area of damage because of impact.Moreover,by matching the toughening polymer surface-loaded and design of the surface pattern,in-plane mechanical properties are unaffected or even improved over laminates made from the identical materials.The proprietary preforms,so-called ESTM-Fabrics,may be handled and infused with the high-temperature RTMable resins such as bismaleimide and polyimide in exactly the same manner as traditional fabrics without surface modification.The RTM conditions for the preform-based toughening is fully compatible with the traditional process procedure,making the technology cost-effective in production.This technology represents a key enabler for the use of low-cost RTM processes for high-temperature resins to supplant prepreg as the building-block material of choice for aeronautical composite structures.
