Polymers do indeed degrade over time, though the rate and mechanism of degradation vary widely among different types of polymers. Factors such as exposure to sunlight (UV radiation), air (oxidation), moisture, and even mechanical stress can contribute to the breakdown of polymer chains, leading to changes in the material's properties, such as reduced strength, flexibility, or color fading. Some polymers, designed to be biodegradable, can decompose quickly under certain conditions, whereas others, like various plastics, can take centuries to break down in the environment. The degradation process is an important consideration in applications ranging from biomedical devices to packaging, influencing both the useful life of polymer products and their environmental impact. Strategies to mitigate degradation include adding stabilizers, developing more stable polymer structures, and promoting recycling and biodegradable alternatives.

To stop ink from smearing, important steps can be taken both before and after the ink is applied. Firstly, using the right type of ink and paper is crucial; for example, waterproof, smudge-proof inks and smoother, higher-quality paper help reduce smearing. For inkjet printers, consider using ink specifically designed for your printer as it's formulated to dry quickly on contact with paper. After writing or printing, allow the ink sufficient time to dry fully. For handwritten documents, you might also try placing a blotter sheet on top of the fresh ink to absorb excess. Additionally, a fixative spray can be applied to the final document to set the ink. Keep in hands-free as much as possible to avoid oil from your skin transferring to the paper and causing smears.

Sanding epoxy can indeed be tough on sanding belts, primarily because epoxy is a plastic that can generate a lot of heat when being sanded. This heat can cause the epoxy to become sticky, potentially clogging the sanding belt and reducing its effectiveness. Moreover, the abrasiveness of the epoxy can wear down the grit on the belt more quickly than wood or other traditional materials. To minimize damage, it’s recommended to use belts specifically designed for harder materials and to keep the epoxy cool during sanding, perhaps by using a slower belt speed or by applying water if the belt material allows.