Thermal‐oxidative aging effects on the properties of long glass fiber reinforced polyamide 10T composites

Abstract

The results of thermal‐oxidative aging effects on the properties of long glass fiber reinforced polyamide 10T (LGF/PA10T) composites were investigated. The composite samples were aged at 240°C in a heat‐blast oven. The aging times were 10, 20, 30, 40, and 50 days. The thermal‐oxidative aging resulted in decline of crystallization behavior, dynamic and static mechanical properties of the LGF/PA10T composites. These observations can be attributed to the decomposition of the molecular chain of PA10T resin, carbonization of the matrix and interfacial debonding between the glass fibers and matrix, as illustrated by scanning electron microscopy and FTIR spectra. At the initial stage of aging, the storage modulus and glass transition temperature first increased and then reduced, which indicated that there was slight crosslinking between the molecular chains. After aging for 50 days, the retention rates of tensile strength, flexural strength, and notch impact strength of the composite samples were 4.9, 6.3, and 9.4% lower, respectively, than that of the unaged samples; thus, it can be concluded that molecular degradation dominated and caused deterioration of interfacial adhesive strength between the fiber and the resin during the whole aging process. Therefore, the LGF/PA10T resin cannot serve for a long‐time at 240°C. POLYM. COMPOS., 39:2117–2125, 2018. © 2016 Society of Plastics Engineers

Thermo-oxidative ageing effect on mechanical properties and morphology of short fibre reinforced polyamide composites – comparison of carbon and glass fibres

“…24,25 In previous publications, research on the thermo-oxidative ageing effect on mechanical properties of glass bre (GF) reinforced polyamide composites were studied. [26][27][28] Song et al investigated thermal-oxidative ageing effects on the thermal and dynamic mechanical properties of long glass bre (LGF) reinforced polyamide 10T composites. 26 Zuo et al 27 studied long-term thermo-oxidative ageing on the ammability and degradation kinetics of PA6/LGF composites which was aged at 160 C. As increasing attention on CF applied in automotive industry, it is important to evaluate ageing behavior of CF reinforced PA composites.…”

“…[26][27][28] Song et al investigated thermal-oxidative ageing effects on the thermal and dynamic mechanical properties of long glass bre (LGF) reinforced polyamide 10T composites. 26 Zuo et al 27 studied long-term thermo-oxidative ageing on the ammability and degradation kinetics of PA6/LGF composites which was aged at 160 C. As increasing attention on CF applied in automotive industry, it is important to evaluate ageing behavior of CF reinforced PA composites. Furthermore, limited studies focused on the relationship between morphology and mechanical performance of short bre reinforced composites (especially for carbon bre) under long-term thermo-oxidative ageing condition.…”

Synthesis and application of new macromolecular hindered phenol antioxidants of polyamide 6

“…The loss modulus ( E ″) signifies the energy degraded or lost as heat in accordance with the cycle of sinusoidal distortion. This is the visco‐elasticity properties of the material, which is more sensitive to the molecular motions and is a function of temperature 38 . Figure 11 and Table 2 show that the E ″ peak decreased, and the E ″ peak flattened with increasing aging time.…”

“…This is the visco-elasticity properties of the material, which is more sensitive to the molecular motions and is a function of temperature. 38 Figure 11 and Table 2 show that the E 00 peak decreased, and the E 00 peak flattened with increasing aging time. The width of E 00 peak represents the movement degree of PA6 chains relative to each other, and it is expected to increase if the internal molecular bonds are broken, such as hydrogen bonds and van der Waals forces.…”

Influence of thermo‐oxidative aging on the dynamical mechanical properties and thermal degradation kinetics of glass fiber‐reinforced PA10T composites

“…However, in the PA polymers, the poor impact strength and the tendency to absorb moisture (existence of polar amide groups) lead to an inferior dimensional stability and limit the applications . Nevertheless, poly(decamethyleneterephthalamide) (PA10T) is a new type of high temperature resistant semi‐aromatic PA, and its low water absorption property and dimensional stability are much better than other aliphatic PAs . Amide groups in PAs form hydrogen bonds between polymeric chains that contribute considerably to its mechanical properties and crystallization behaviors.…”