Explanation

Many ordered or disordered micro grooves visible to the naked eye on the surface or inside of macromolecule surface of materials under the action of stress or solvent are silvery white under the action of light, which is a unique crack of macromolecule. It can only be formed under tensile stress, and the surface is always perpendicular to the direction of tensile stress. Under the action of tensile stress, microdefect in macromolecule form stress concentration, which leads to the formation of micropores and further nucleation. On the plane perpendicular to the tensile stress, flat wedge-shaped micro fiber bundles are formed. It is composed of substance and cavity. The substance is a highly orientation macromolecule microfiber. Voids are connected. Quality has a certain mechanical strength and viscoelasticity. Therefore, it can bear a certain load, and can disorientation and disappear above the glass transition temperature, which is called self healing. Solvents can accelerate initiation and growth, leading to accelerated destruction of macromolecule. The initiation and growth mechanism of the study is very important for understanding the fracture, toughening, environmental stress cracking and fatigue failure of macromolecule.

Classification