In plastic material selection, PPH (homopolymer polypropylene) and PPC (copolymer polypropylene) from the polypropylene (PP) family frequently capture the attention of engineering designers and procurement professionals. Despite their similar names, their performance characteristics and suitable applications each have distinct advantages. This article will provide a detailed analysis of the fundamental differences between these two materials from a practical application perspective.
Chemical Structure Differences: The Fundamental Determinant of Properties
PPH is the polymerization product of pure propylene monomers, featuring a highly ordered molecular chain arrangement and high crystallinity. This structure resembles “neatly aligned soldiers in formation,” endowing the material with excellent rigidity and heat resistance.
PPC, however, is a copolymer of propylene and a small amount of ethylene (typically 1-7%). Its molecular chains feature irregular arrangements, resembling a “flexible, interwoven network.” This structure significantly enhances the material's toughness and impact resistance.
Performance Characteristics Comparison: Understanding the Differences at a Glance
Mechanical Properties
PPH: Excels in rigidity and strength. Its tensile strength reaches 35-40 MPa, with a high flexural modulus, making it suitable for sustained load-bearing applications.
PPC: Its primary advantage lies in toughness and impact resistance. PPC maintains good impact performance even at -10°C, whereas PPH may become brittle under the same conditions.
Thermal Performance
PPH: Features a higher heat deflection temperature (100-110°C), making it more suitable for high-temperature applications.
PPC: Has a slightly lower heat deflection temperature (90-100°C) but offers better adaptability to temperature fluctuations and a wider processing window.
Chemical Stability
Both exhibit good chemical resistance, but PPH demonstrates superior tolerance in strong acid and alkali environments, making it more suitable for chemical equipment applications.
