Polystyrene (PS) and polyvinyl chloride (PVC) are both common plastic materials, but they have significant differences in structure, performance, use and safety:
I. Comparison of basic properties
| Item | Polystyrene (PS) | Polyvinyl chloride (PVC) |
| Full name | Polystyrene | Polyvinyl Chloride |
| Chemical structure | Styrene polymer | Polyvinyl chloride-containing polymer |
| Common appearance | Transparent, brittle, light | Opaque, tough, adjustable soft or hard |
| Density | About 1.05 g/cm³ | About 1.35–1.45 g/cm³ |
| Heat deformation temperature | About 90℃ | About 60–80℃ (variable with additives) |
| Whether it contains chlorine | No | Yes (containing chlorine element) |
| Flammability | Flammable | Good flame retardancy, releases chlorine when burning |
| Processing method | Injection molding, foaming, extrusion, etc. | Blow molding, injection molding, extrusion, calendering, etc. |
- Comparison of performance characteristics
| Performance | PS | PVC |
| Rigidity | High, hard but brittle | Medium, softness can be adjusted according to the formula |
| Toughness | Poor, easy to break | Good, strong plasticity |
| Transparency | Highly transparent (such as GPPS) | Usually opaque (adjustable transparency) |
| Heat resistance | General, not resistant to high temperature | General, can be slightly improved after adding stabilizers |
| Chemical resistance | General acid and alkali resistance | Strong acid and alkali resistance and corrosion resistance |
| Electrical insulation | Very good | Excellent |
- Differences in common uses
| Application areas | Uses of PS | Uses of PVC |
| Packaging materials | Foam boxes, fast food boxes, CD boxes, transparent packaging boxes | Food cling film, plastic bottles |
| Construction industry | Rarely used | Water pipes, window frames, cable sheaths, floor leather |
| Medical supplies | Disposable items such as culture dishes and test kits | Infusion tubes, blood bags (using soft PVC) |
| Industrial parts | Electronic housings, toys, home appliance parts | Pipes, valves, industrial anti-corrosion coatings |
| Stationery and crafts | Pen cases, photo frames, sign boards | Book covers, table mats, advertising films |