Thermoplastic comparison
PVC, rigid (uPVC) vs PVC, plasticized (flexible, PVC-P)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
Which to choose
Identical polymer, different plasticiser content: adding plasticiser drops the glass transition below room temperature and turns a rigid pipe material into a flexible one. Rigid PVC is stiff and strong for pipe, window frames and cladding; flexible PVC is for hose, cable insulation and sheeting — at the cost of plasticiser that can migrate out over time.
| Property | PVC, rigid (uPVC) | PVC, plasticized (flexible, PVC-P) | Difference |
|---|---|---|---|
| Density | 1.4 g/cm³ | 1.4 g/cm³ | identical |
| Young's modulus E | 3 GPa | 1.4 GPa | PVC, rigid (uPVC) — 2.1× higher |
| Tensile strength | 48 MPa | 16 MPa | PVC, rigid (uPVC) — 3.0× higher |
| Glass transition Tg | 82 °C | 75 °C | PVC, rigid (uPVC) — 7 °C higher |
Where these numbers come from
- Callister & Rethwisch, Materials Science and Engineering, 10th ed.
- MakeItFrom.com materials database — typical grade values
Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.