Kinetics for the degradation of nylon and Kevlar parachute materials

Conference · Tue Dec 31 23:00:00 EST 1985

OSTI ID:5473320

Auerbach, I

The degradation of nylon 66 and Kevlar 29 yarns at elevated temperatures and over a broad range of humidities was studied and a rate relationship developed which models the degradation and permits computation of rate constants. The degradation rates are slow initially due to the presence of an inhibitor but increase rapidly as the inhibitor is depleted. The effect of relative humidity (RH) can be very large especially at values in the 100% range. An exponential relationship exists for nylon between the rate constant and RH. Kinetic parameters were evaluated and the rate constants at 25/sup 0/C calculated. These values showed that the tensile strength of nylon 66 will remain at a safe level over a 25-year period if the humidity is maintained at the 10% range or less. Kevlar 29 is more resistant and can tolerate humidity levels in the range of 90% or less. Degradation is governed by thermal-oxidative and moisture induced mechanisms. At the very high humidities the moisture induced degradation predominates. A relationship is developed which predicts the degradation rate over a very broad range of temperatures and humidities.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA). Aerodynamics Dept.
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5473320
• Report Number(s): SAND-86-0853C; CONF-861050-3; ON: DE86014290
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360405* -- Materials-- Polymers & Plastics-- Degradation & Erosion-- (-1987)
ARAMIDS
HIGH TEMPERATURE
HUMIDITY
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
NYLON
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PARACHUTES
PERFORMANCE
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYAMIDES
POLYMERS
SERVICE LIFE
SYNTHETIC MATERIALS
TENSILE PROPERTIES
TESTING
TEXTILES