Polyamide Hydrolysis Mechanisms and Glass Fiber Matrix Interphase Degradation Kinetics
Polyamide hydrolysis breaks backbone bonds while fluid wicking degrades glass interphases, requiring strict sizing specs and acid end-group tracking.
Capillary Wicking
Meaning
Spontaneous movement of liquid through narrow spaces in a porous solid driven by molecular attraction and surface tension. Capillary wicking occurs when the adhesion of the liquid to the wall exceeds the internal cohesion of the fluid. The process continues until the gravitational head of the liquid column matches the capillary pressure.
Fluid Dynamics
Molecular forces at the liquid-solid interface drive the liquid forward into dry spaces. The rate of flow depends on the diameter of the pores. Smaller channels generate higher pressure but also increase the frictional resistance.
Viscosity of the fluid and the wettability of the solid surface determine the speed of penetration.
Measurement Metric
Standard procedures often involve dipping a vertical strip of textile or porous plastic into a reservoir of colored dye. Technicians record the height reached by the liquid over a specific time interval. The resulting data determine how effectively a garment or filter pulls moisture away from a surface.
Comparison between different materials requires identical temperature and humidity conditions.
Saturation Barrier
Movement stops when the resistance within the material counteracts the driving surface tension. Evaporation at the dry end can also limit the final reach of the fluid. Highly viscous liquids or hydrophobic surface treatments prevent the process from starting.
Mechanical compression of the porous structure alters the pore geometry and restricts flow.