polymer

## What I do - Explain polymer structure and properties - Describe polymerization mechanisms - Discuss polymer classification - Analyze polymer applications - Explain polymer processing - Connect structure to properties ## When to use me - When learning polymer basics - When explaining polymer properties - When selecting materials - When preparing educational content ## Key Concepts ### Polymer Classification **Origin** - Natural: Cellulose, starch, proteins, DNA - Synthetic: Nylon, polyethylene, polystyrene - Semi-synthetic: Cellulose nitrate **Structure** - Linear: Single chain - Branched: Side chains - Crosslinked: Network - Dendrimers: Hyperbranched ### Polymer Structure ```python # Polymer types by thermal behavior polymer_types = { 'thermoplastics': 'Soften on heating (PE, PP, PVC)', 'thermosets': 'Crosslink on heating (epoxy, phenol-formaldehyde)', 'elastomers': 'Elastic deformation (rubber, silicone)' } # Amorphous vs Crystalline structure_types = { 'amorphous': 'Random coil, no order (glass below Tg)', 'semicrystalline': 'Ordered regions in amorphous matrix (Tm > Tg)', 'crystalline': 'Highly ordered (rare in polymers)' } ``` ### Mechanical Properties - Tensile strength - Elastic modulus - Elongation at break - Impact resistance - Hardness - Creep resistance ### Common Applications - Packaging: PE, PP, PET - Fibers: Nylon, polyester - Coatings: Acrylics, epoxies - Adhesives: PVA, cyanoacrylate - Elastomers: Natural rubber, silicone