author
Bobby Brown
Post 2016-02-19
PP Material Characterization

Contents


What is PP (Polypropylene) ?

Polypropylene (PP) is a semi-crystalline thermoplastic polymer known for its high impact resistance, robust mechanical properties, and resistance to various organic solvents, acids, and alkalis. This versatile material finds extensive applications across multiple industries due to its unique properties.


Properties

Structure and Performance

Polypropylene (PP) and polyethylene (PE) have very similar molecular structures, which results in many similar properties, particularly in their behavior in solutions and electrical characteristics. The presence of a methyl side group in the molecular structure of polypropylene significantly enhances its mechanical properties and thermal performance. However, this structural feature also makes polypropylene more susceptible to oxidative degradation when exposed to ultraviolet (UV) light and heat, resulting in relatively reduced chemical resistance.

Mechanical and Thermal

Polypropylene (PP) exhibits outstanding chemical stability and heat resistance. Its inherent properties are similar to those of high-density polyethylene (HDPE), but with slightly lower crystallinity, resulting in a generally translucent appearance and comparable hardness to HDPE. The properties of PP are mainly influenced by factors such as molecular weight and molecular weight distribution, crystallinity, the proportion of comonomers, and isotacticity.

Melting Point and Thermal Expansion

Polypropylene (PP) has a melting point range that is typically determined by differential scanning calorimetry (DSC) to find its peak temperature. Perfect isotactic PP has a melting point of 171°C, while commercial grades of PP typically have melting points ranging from 160°C to 166°C, depending on the proportion of atactic material and the degree of crystallinity. Syndiotactic polypropylene has a melting point of approximately 130°C and a crystallinity of around 30%.

PP Chemical resistance chart

How to read the chart

  • Meaning of symbol: OK:Recommended. △:Must confirm if usable by testing in advanced. X:Not recommended. N/A:Not Applicable
  • This chart only provides the result of a single chemical to material, if a client uses more than one kind of chemical at the same time, please choose material by experience.
  • This chart is for reference only which is not applicable to all working environments. Please refer to design equipment according to practical experience.
Category Chemical PP
Organic acids Acetic acid OK (20%)
Acetic acid, glacial N/A
Acetic anhydride N/A
Citric acid N/A
Organic compound Acetaldehyde OK (20˚C)
Acetone △ (20˚C)
Methyl alcohol N/A
Aniline N/A
Benzaldehyde OK (70˚C)
X (100˚C)
Benzene OK (20˚C)
X (70˚C)
Benzyl alcohol OK
Benzyl chloride N/A
Corn oil N/A
Ethanol OK (96% @ 70˚C)
Ethylene glycol OK
Fatty acid N/A
Formaldehyde OK (10%)
OK (40%)
Formic acid N/A
Hexane X (20˚C)
Lactic acid N/A
Methanol OK (20˚C)
Paraffin oil N/A
Petroleum N/A
Phenol N/A
Propane, liq N/A
Propanol N/A
Stearic acid N/A
Tannic acid N/A
Tartaric acid N/A
Toluene X
Urea N/A
Inorganic compound Ammonia N/A
Ammonium chloride N/A
Ammonium hydroxide N/A
Ammonium nitrate N/A
Ammonium sulfate N/A
Aqua regia N/A
Barium chloride N/A
Barium hydroxide N/A
Brine N/A
Calcium Chloride N/A
Calcium hydroxide N/A
Carbonic acid N/A
Chloric acid N/A
Chlorine OK (10%)
△ (30%)
Detergent N/A
Hydrobromic acid N/A
Hydrochloric acid N/A
Hydrofluoric acid OK (20˚C)
Hydrogen peroxide N/A
Nitric acid OK (20˚C)
Phosphoric acid OK (70˚C)
Potassium hydroxide N/A
Potassium nitrate N/A
Potassium sulfate N/A
Sodium carbonate N/A
Sodium hydroxide OK (50%)
Sodium nitrate N/A
Sulfuric acid OK (30% @ 70˚C)
△ (30% @ 100˚C)
OK (100% @ 20˚C)
△ (100% @ 70˚C)
Sulfur dioxide N/A 

Reference

  1. ^ Polypropylene - Wikipedia
Products you may also like
Related articles
Bobby Brown    2023-8-8
Bobby Brown    2023-8-8

Contact Us