The physical and mechanical behavior of polymer materials results from the interplay between chain flexibility, interchain interactions, crystallinity, and molecular weight distribution. Common properties include low density, chemical resistance, electrical insulation, and ease of processing. By adding fillers, plasticizers, crosslinkers, or reinforcing agents such as carbon fibers or glass fibers, the performance of polymers can be tailored for specific uses. Thermoplastic polymers (e.g., polyethylene, polypropylene, PET) can be melted and reshaped repeatedly, while thermosetting polymers (e.g., epoxy, phenolic) cure irreversibly and form highly rigid networks. Elastomers such as natural rubber, silicone, and polyurethane provide elasticity and resilience.
Applications span an extensive range of industries. In packaging, high-density polyethylene and PET offer lightweight, durable, and recyclable solutions. In the automotive sector, polymer composites contribute to weight reduction and crash safety. Electronics rely on polymers for insulation, protective casings, and flexible displays. Medical devices and biomedical implants use biocompatible polymers like poly(lactic acid) and poly(glycolic acid). Emerging fields such as additive manufacturing increasingly depend on specialty polymers that can be precisely extruded or photopolymerized.
Environmental considerations are critical in modern polymer use. The non-biodegradability of many conventional plastics leads to long-term waste accumulation. Consequently, research focuses on developing bio-based polymers, improving recycling pathways, and incorporating biodegradable additives. Legislative measures, such as extended producer responsibility schemes and bans on single-use plastics, shape market trends and drive innovation toward more sustainable polymer solutions.