When winter comes, we all know that plastic will become very brittle in winter. What's the reason?
The main component of plastics is macromolecular aggregates. Macromolecules are characterized by slow movement at low temperature and fast movement at high temperature. In winter, the molecular motion is slow. When the plastic is subjected to external force, the object deforms. Due to the slow molecular motion, the external force is not easy to transfer (internal stress) or consume (molecular chain friction), so it is easy to produce internal stress concentration. When the internal stress is large to a certain extent, the macromolecule will break and cause cracks. The cracks will lead to internal stress concentration and propagation, and the plastic will break.
Treatment: generally, injecting a small amount of water into the bag can reduce the fracture
