Aliphatic Polyamide Properties
• Aliphatic polyamides are semi-crystalline as they consist of crystalline and amorphous phases.
• Crystallinity results from the polar amide groups, which undergo hydrogen bonding between the carbonyl and NH groups in adjacent sections of the PA chains.
• The regular spatial alignment of amide groups allows a high degree of hydrogen bonding to develop when chains are aligned together.
• The more random amorphous regions have a much lower degree of hydrogen bonding.
• A semi-crystalline structure gives rise to a good balance of properties.
• The crystalline regions contribute to the hardness, yield strength, chemical resistance, creep resistance and temperature stability.
• The amorphous areas contribute to the impact resistance and high elongation.