This topic will cover the basic definition of polymers, their classification, molecular structure, and the importance of polymers in various industries.
Introduction to Polymers – Study Notes
| Category | Source | Typical Examples | Notable Features |
|---|---|---|---|
| Natural Polymers | Biological origin | Cellulose, DNA, proteins, silk, rubber | Biodegradable, often functional in living systems |
| Synthetic Polymers | Man‑made (petrochemical feedstock) | Polyethylene (PE), Polystyrene (PS), Polyvinyl chloride (PVC), Nylon, Teflon (PTFE) | Tailorable properties, mass‑produced |
| Biopolymers (bio‑based & biodegradable) | Renewable resources (e.g., corn, sugarcane) | Polylactic acid (PLA), Polyhydroxyalkanoates (PHA) | Reduced environmental impact |
| Thermoplastics vs. Thermosets | Based on thermal behavior | Thermoplastics: PE, PP, PVC (melt & reshape) Thermosets: Epoxy, Phenolic resin (cure into a rigid network) |
Recyclability vs. dimensional stability |
| Mechanism | Process Overview | Typical Monomers | Example Products |
|---|---|---|---|
| Addition (Chain‑Growth) Polymerization | Initiator creates a reactive site; monomers add one by one without by‑products. | Vinyl monomers (CH₂=CHX) | Polyethylene, Polystyrene, Poly(methyl methacrylate) |
| Condensation (Step‑Growth) Polymerization | Monomers with two functional groups react, releasing a small molecule (e.g., water, HCl). | Diols & diacids, diamines & diacids | Polyesters (PET), Polyamides (Nylon), Polyurethanes |
| Ring‑Opening Polymerization | Cyclic monomers open and link, often giving polymers with fewer side groups. | Lactides, epoxides | Polylactic acid (PLA), Polycaprolactone |
| Copolymerization | Two or more different monomers are polymerized together, creating tailored sequences. | Any compatible monomers | Styrene‑butadiene rubber (SBR), ABS (acrylonitrile‑butadiene‑styrene) |
| Property | What It Describes | Influencing Factors |
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