Modified fiber: Strengthening molecular structure, improving performance and application potential

1. Preparation principle of modified fiber
The preparation of modified fiber is mainly based on two strategies: chemical modification and physical modification. Chemical modification usually involves introducing new functional groups, polymer segments on the surface or inside of the fiber, or forming a new network structure through cross-linking reaction, so as to change the original molecular arrangement and interaction force of the fiber. For example, through chemical reactions such as esterification and amidation, hydrophobic groups can be introduced into cellulose fibers to improve the water resistance and anti-aging properties of the fiber. Physical modification focuses on using mechanical force, thermal energy, radiation and other means to change the crystallinity, orientation or surface morphology of the fiber without changing its chemical composition. For example, through stretching treatment, the fiber molecular chain can be arranged more tightly and orderly along the axial direction, thereby improving its strength and modulus.

2. Performance improvement mechanism
The strength and toughness of the modified fiber are significantly improved, mainly due to the following aspects:
Reinforcement of molecular chains: Chemical modification enhances the interaction between molecular chains by introducing strong bonds or forming a network structure, making the fiber less likely to break when subjected to external forces.
Optimization of crystallinity: Physical modification adjusts the crystallinity of the fiber to form more orderly arranged crystal regions inside the fiber, which can effectively resist the damage of external forces.
Improvement of surface properties: Whether chemical or physical modification, it helps to improve the surface smoothness and interfacial bonding of the fiber, and reduce the performance degradation caused by friction and wear during use.
Functional expansion: Modified fibers can also introduce specific functional groups according to needs, such as antibacterial, flame retardant, antistatic, etc., to further broaden their application scope.
3. Application fields and prospects
Modified fibers have great application potential in many fields due to their excellent physical and mechanical properties and diverse functional characteristics:

Textile industry: Clothing and home textile products made of modified fibers are not only more durable, but also meet specific functional requirements, such as quick drying, warmth preservation, antibacterial, etc.
Building materials: Adding modified fibers to concrete and gypsum boards can significantly improve the crack resistance, toughness and durability of the materials, which is particularly suitable for buildings in earthquake-prone areas.
Automobile manufacturing: Modified fiber composite materials are widely used in the manufacture of automobile bodies and interior parts due to their light weight, high strength and impact resistance, which helps to reduce vehicle weight and improve fuel efficiency.
Aerospace: In extreme environments, modified fiber materials can maintain good mechanical properties and stability, making them an ideal choice for manufacturing aircraft, satellites and other spacecraft structural parts.