Temperature and frequency‐dependent creep and recovery studies on PVDF‐HFP/organo‐modified layered double hydroxides nanocomposites

An eco-friendly flame retardant unsaturated polyester resin (UPR) material was prepared by combination organic magnesium hydroxide (OMH) and expandable graphite (EG). Different from direct addition of magnesium hydroxide (MH) in UPR matrix-like traditional method, OMH as a reactive monomer participates in the polycondensation reaction of UPR was more effective in improving the compatibility of flame retardant with matrix. Interestingly, the flame retardant UPR composites exhibited a more satisfactory flame retardant effect when a certain amount of 8 wt % EG was added into UPR/OMH matrix because of the synergistic effect between OMH and EG, resulted in the limited oxygen index from 21.7 to 28.5% and UL-94 test passed V-0 rating. Moreover, the peak heat release rate, total heat release, and smoke production rate of flame retardant UPR composites significantly reduced. The excellent flame retardancy was due to the formation of a dense and continuous carbon layer in the later stages of combustion.

Section: Resultssupporting

confidence: 69%

Influence of expandable graphite on flame retardancy and thermal stability property of unsaturated polyester resins/organic magnesium hydroxide composites

Zeng

Shi

et al. 2019

“…As the temperature and tension went up, the creep strain and recovery strain of PET harness cord gradually increased. The literatures also presented the similar results. For instance, under the conditions of 5, 10, and 15% BF, the creep strain and recovery strain of PET harness cord displayed an increment of 185.7 and 331.1%, 133.0 and 353.8%, 80.2 and 258.9%, respectively, on increasing the temperature from 40 to 100 °C.…”

Section: Resultssupporting

confidence: 77%

“…Lorandi studied the creep behavior of carbon/epoxy non‐crimp fabric composites by using Burger's model. Mahdavi and Shojaei used the burgers model to explore and analyze the temperature dependence of viscoelastic properties of the nanocomposites. The materials of the above researches were mostly fibers, filaments, yarns, and composites.…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature on tensile and creep‐recovery properties of braided polyester harness cord

Xie

Shen

2019

Tensile and creep‐recovery properties of braided polyester (PET) harness cord under various temperature and tension were studied by using an Instron universal tester. The study reveals that the tensile properties are highly related to the temperature, with a decrease of 29.6, 50.0, and 33.8% in initial modulus, yield force, and breaking force (BF), respectively, as increasing the temperature from 25 to 100 °C. Under the condition of 5% BF, the creep and recovery strain of harness cord increased by 185.7 and 353.8% separately, when the temperature increased from 40 to 100 °C, indicating the significant effect of temperature and tension on the creep‐recovery properties. The similar tendencies were also observed under the conditions of 10 and 15% BF. These results could be well described by Burgers four‐element model. During the 1.5 h creep test, only instant elastic and retarded elastic deformation could be observed and accounting for 56.1–84.3% and 15.2–43.4% of the total creep deformation, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47864.

“…29,30 The calculations were done using reference temperature (T ref ) of 30 C on studied samples shown in Figure 7(d,f ). 29,30 The calculations were done using reference temperature (T ref ) of 30 C on studied samples shown in Figure 7(d,f ).…”

Section: Creep and Recovery Analysismentioning

confidence: 99%

Disclosing the role of surface and bulk erosion on the viscoelastic behavior of biodegradable poly(ε‐caprolactone)/poly(lactic acid)/hydroxyapatite nanocomposites

Shojaei

Nikuei

Goodarzi

et al. 2018

Self Cite

In this study, biodegradable polymer blends and their nanocomposites were prepared using poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) as blending components and hydroxyapatite (HA) nanoparticles as reinforcement. X-ray diffraction spectra showed that the presence of HA nanoparticles enhanced the intensity of the peaks (100) and (200) corresponding to the PCL's crystalline planes. The transmission electron microscopy images confirmed the high tendency of HA nanoparticles to locate in the PLA phase. The water uptake values of samples measured at pH 4 were more than those measured at other pH values. The weight loss behavior of blends in acidic medium was completely different from that in basic and neutral media. The Williams-Landel-Ferry equation and time-temperature superposition principle were applied to the creep compliance of the samples and their master curves were determined at reference temperature of 30 C, and the mechanical properties of samples were predicted in other conditions. The effect of pH on the creep-recovery response of studied samples was analyzed. From this analysis, it could be found that at pH 4, the creep stain increased, while, at pH 7, there was no a significant change in the viscoelastic property.