Chemical Resistance of Plastics
Plastics are polymers that encompass a large variety of synthetic or semi-synthetic materials. They can be moulded, extruded or pressed into solid objects of various shapes and have been adapted to make use of their properties including being lightweight, durable, flexible, and inexpensive to produce. Plastics can be affected by their environment and it is important to know their limitations and stability when in contact with extreme cold or heat, radiation and other chemicals.
Table 1. Physical Properties of Plastics
* Mind the chemical and temperature suitability.
** Caution necessary when used in a microwave oven: Heating can release amounts of melamine and formaldehyde that can be harmful to health.
The chemical stability of plastics when in contact with various substances are classified as follows:
| ✓ |
Very good chemical resistance |
| ! | Good to limited chemical resistance Within 7‐30 days, continuous exposure to media causes minor and reversible damage (e.g. swelling, softening, loss of mechanical strength, discolouration). |
| ✕ | Poor chemical resistance Not suitable for exposure to media as immediate damage may occur (e.g. loss of mechanical strength, deformation, discolouration, cracking, liquefaction). |
Table 2. Chemical Resistance of Plastics to Various Substance Classes
Table 3. Chemical Stability of Plastics
Plastics Key
| EPDM | Ethylene Propylene Diene Monomer | PFA | Perfluoroalkoxy |
| ETFE | Ethylene Tetrafluoroethylene | PMMA | Polymethyl Methacrylate |
| FEP | Fluorinated Ethylene Propylene | PMP | Polymethylpentene |
| FKM | Fluoroelastomer (Viton) | POM | Polyoxymethylene (Acetal) |
| HDPE | High-Density Polyethylene | PP | Polypropylene |
| LDPE | Low-Density Polyethylene | PS | Polystyrene |
| MF | Melamine Formaldehyde | PTFE | Polytetrafluoroethylene |
| NR | Natural Rubber | PVC | Polyvinyl Chloride |
| PA | Polyamide (Nylon) | SAN | Styrene Acrylonitrile |
| PC | Polycarbonate | SI |
Silicone |
| PET | Polyethylene Terephthalate |