Polymers: Giant Molecules
Polymers are large, long-chain molecules built from repeated subunits called monomers. They are omnipresent in nature as proteins, cellulose, and DNA, and synthetically as plastics, nylon, and silicone.
Monomers Joining Forces
Monomers can connect in various ways. A dehydration reaction, or condensation polymerization, links them by removing water. Alternatively, addition polymerization involves radicals to add monomers without byproducts.
Polymer Structure Complexity
Polymers exhibit diverse structures: linear, branched, or cross-linked. Linear and branched polymers are thermoplastic, softening on heating, while cross-linked polymers are thermosetting, maintaining their strength at high temperatures.
Crystallinity and Polymers
Polymers can be amorphous or semi-crystalline. Amorphous polymers are random and entangled, while semi-crystalline polymers have ordered regions, affecting their transparency, density, and melting points.
Copolymers: Mixed Monomers
Copolymers contain two or more different types of monomers. The arrangement of these monomers (random, alternating, block, or graft) significantly alters the material's properties, leading to applications from adhesives to textiles.
Living Polymerization
Living polymerization is a method where the active growth of a polymer chain endures without termination. This precision leads to polymers with uniform molecular weight and architecture, critical for advanced applications in medicine and engineering.
Environmental Impact
The durability of synthetic polymers poses environmental challenges. Biopolymers and biodegradable plastics, derived from renewable resources, offer sustainable alternatives to traditional petroleum-based polymers.
What are polymers built from?
Single-unit materials
Repeated subunit monomers
Condensed water molecules
Company