Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| 1 % | D | D | corrected, see below |
| 30 % | D | D | corrected, see below |
| 45 % | D | D | corrected, see below |
| 50 % | D | D | corrected, see below |
| 60 % | D | D | corrected, see below |
| concentrated | D | D | corrected, see below |
Corrected and disputed values
- PVDF (1 %): source value 1/1, shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
- PVDF (30 %): source value (2), shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
- PVDF (45 %): source value (2), shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
- PVDF (50 %): source value 3/3, shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
- PVDF (60 %): source value (2), shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
- PVDF (concentrated): source value (2), shown as 4/4. The resin manufacturer lists PVDF homopolymer as not recommended for sodium hydroxide at every concentration, and two further charts rate it D. The source rates it A to C, mostly as an estimate. [1] [2] [3]
Source values use the scale 1 (very good) to 4 (not resistant); 1 = A, 4 = D.
Material comparison at 20 °C
Resistance overview
PVDF maintains a consistent rating of D across all 6 tested concentrations (1 %, 30 %, 45 %, 50 %, 60 %, concentrated) of Sodium Hydroxide (Caustic Soda) at 20 °C. The fact that the rating does not change with concentration within the tested range simplifies material selection, though the boundary conditions beyond this range remain untested. The rating remains stable between 20 °C and 50 °C, which means this material can also handle moderately elevated process temperatures without additional risk.
Application context
Sodium Hydroxide (Caustic Soda) is commonly encountered in textile processing and pulp and paper. PVDF (Polyvinylidene fluoride) is a fluoropolymer typically used for seals, gaskets, valve seats and lined equipment. Because Sodium Hydroxide (Caustic Soda) is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
PVDF is not recommended for use with Sodium Hydroxide (Caustic Soda). The D rating indicates that the material will suffer rapid and severe degradation, which may include cracking, dissolution, severe swelling, or complete structural failure. Using this combination risks equipment damage, leaks, and potential safety incidents. Consider using HDPE, LDPE, Nylon (PA) instead, which are rated A for this chemical and offer reliable long-term performance.
Did you know?
When choosing between fluoropolymers for Sodium Hydroxide (Caustic Soda) service, engineers consider not just the resistance rating but also factors such as permeation rate, creep resistance, and weldability.
Materials rated A or B at 20 °C
Based on the row for 60 %, 20 °C.
- Thermoplastics
- HDPE A, PP A, LDPE A, Nylon (PA) A, Polystyrene A, Polysulfone A, PMP A
- Fluoropolymers
- PTFE A
- Elastomers
- EPDM A, NBR B
- Metals
- SS 316 A, SS 304 A
About PVDF
PVDF resists acids, halogens and hydrocarbons. Strong bases, amines, ketones and esters attack it. Service temperature is up to about 150 °C.
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
About this data
The ratings come from the chemical resistance list published by Bürkle GmbH, which compiled them from raw-material manufacturers’ data. They describe laboratory tests on the raw material at 20 °C and 50 °C.
A finished part also sees pressure, mechanical stress, welds and mixtures that a laboratory test does not. Treat the rating as a first filter and test under your own conditions before relying on it.