How To Identify Common Rubber Materials Using The Burning Method

1. Natural Rubber (NR):

• Appearance: Pale yellow and semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: Produces black smoke, a dark yellow flame, and becomes soft.

• Residue Odor: Smells like rubber with non-sticky residue.

2. Isoprene Rubber (IR):

• Appearance: Pale yellow and semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: Black smoke, dark yellow flame, becomes soft.

• Residue Odor: Smells like rubber with non-sticky residue.

3. Butadiene Rubber (BR):

• Appearance: Pale yellow and semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: Black smoke, dark yellow flame, becomes soft.

• Residue Odor: Non-sticky residue.

4. Styrene-Butadiene Rubber (SBR):

• Appearance: Pale yellow or light brown-red, semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: Black smoke, dark yellow flame, becomes soft.

• Residue Odor: Smells like styrene, slightly expands, non-sticky residue.

5. Nitrile Rubber (NBR):

• Appearance: Pale yellow to light brown, semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: Black smoke, dark yellow flame, becomes soft.

• Residue Odor: Smells like burning protein, non-sticky residue.

6. Butyl Rubber (IIR):

• Appearance: Colorless, transparent to semi-transparent.

• Burning Characteristics: Burns easily.

• Flame Characteristics: No smoke, dispersed flame.

• Residue Odor: Melts, sweet-smelling.

7. Ethylene Propylene Diene Monomer (EPDM):

• Appearance: White, opaque.

• Burning Characteristics: No smoke, dispersed flame, purple flame.

• Residue Odor: Smells like paraffin.

8. Chloroprene Rubber (CR):

• Appearance: Pale yellow to light brown, opaque.

• Burning Characteristics: Difficult to burn.

• Flame Characteristics: Flame appears green.

• Residue Odor: Expansion, smells like hydrochloric acid.

9. Silicone Rubber (Q):

• Appearance: White, semi-transparent to opaque.

• Burning Characteristics: Moderately flammable.

• Flame Characteristics: White smoke, bright white flame.

• Residue Odor: White ash, minimal odor.

10. Fluoroelastomer (FKM):

• Appearance: White, opaque.

• Burning Characteristics: Extremely difficult to burn.

• Flame Characteristics: Self-extinguishing, green flame.

• Residue Odor: Softens, emits toxic gases.

1. Polyurethane rubber: Highly flammable, blue at the base of the flame, bubbling without smoke, dripping.

2. Propionic acid resin: Flammable, does not self-extinguish, blue base of the flame, bubbles and crackling during burning.

3. Polysulfide rubber: Highly flammable, blue-purple flame, outer layer is brick red, produces hydrogen sulfide odor.

Using analytical instruments (such as infrared spectroscopy, nuclear magnetic resonance, etc.) to identify rubber products is the most reliable method. However, due to expensive equipment and complex processes, there are limitations. For a quick and simple result, differentiating rubber varieties can be done through the following methods:

1. Burning method: Observing the burning characteristics, flame features, surface status, and gas odors while slowly bringing the sample towards the flame. Different rubber types have distinct burning characteristics, such as black smoke and sparks for unsaturated or benzene-containing rubbers, difficulty in burning or self-ignition for chlorine-containing rubbers, etc.

2. Chemical reagent color method: Using hot metal rods on the rubber sample to produce smoke, and exposing the fumes to test paper soaked in specific chemical reagents to determine the color change for identifying the rubber type.

This method is a simple way to distinguish various rubber types. For a more reliable identification, the use of instruments like infrared spectroscopy and nuclear magnetic resonance is recommended, although they might be expensive and technically intricate.