Polyamide Resin Composition with Reactive Modifier for Fatigue Resistance

The patent uses a composite material system consisting of polyamide resin (A) as the continuous phase and modifying polymer (C) as the dispersed phase. The modifying polymer contains functional groups that react with the polyamide resin to form an interpenetrating network structure, creating a composite material that combines the excellent chemical resistance and heat resistance of polyamide with the improved impact and fatigue resistance provided by the modifying polymer.

The patent changes the chemical parameters of the system by introducing functional groups (such as carboxyl groups, hydroxyl groups, amino groups, or isocyanate groups) into the modifying polymer. These functional groups react with the polyamide resin to form chemical bonds, fundamentally changing the interfacial properties and creating a more robust composite structure that simultaneously improves impact resistance and fatigue resistance.

The modifying polymer acts as an intermediary between the polyamide resin matrix and the dispersed phase. The functional groups on the modifying polymer react with the polyamide resin to create strong interfacial adhesion, while the elastomeric nature of the modifying polymer provides impact resistance. This intermediary structure prevents interfacial failure under dynamic strain, thereby improving both impact resistance and fatigue resistance simultaneously.

The patent changes the chemical composition of the modifier by incorporating specific functional groups that react with polyamide resin. This chemical modification transforms the interface from a weak physical blend to a strong chemical bond, enabling the modifier to effectively transfer and distribute stress under dynamic loading, thus improving fatigue resistance while maintaining impact resistance.

The modifying polymer with functional groups serves as a chemical intermediary that forms strong bonds between the polyamide resin matrix and the dispersed phase. The functional groups (carboxyl, hydroxyl, amino, or isocyanate) react with the polyamide resin to create a chemically bonded interface that can withstand large loads during extension and flexing, preventing interfacial failure and significantly improving flexing fatigue resistance.

The patent fundamentally changes the interfacial properties by introducing chemical reactivity through functional groups. This chemical modification increases the interfacial strength from a weak physical interface to a strong chemical bond, enabling the composite to withstand the large cyclic loads encountered during extension and flexing without interfacial failure.