Dynamic Mechanical Properties of PPESK/Silica Hybrid Materials

Qin

et al. 2016

Polymer Composites

Long glass fibers reinforced thermoplastic polyurethane and poly(butylene terephthalate) with the compatibilizer of poly(ethylene-butylacrylate-glycidyl methacrylate copolymer) (LGF/TPU/PBT/PTW) composites were prepared by using self-designed impregnation device. Various rheological plots including viscosity curve, storage modulus, loss modulus, loss angle, Cole-Cole plot, and relaxation spectrum were used to characterization of rheological properties. Dynamic mechanical thermal analysis (DMA) results indicated that "double tan d behavior" of composites is observed. The activation energies of a and b-relaxation process of loss modulus and tan d of the LGF/TPU/PBT/ PTW composites gradually increased with long glass fibers content. Moreover, activation energies for the glass transition relaxation determined from loss tangent peaks are more reliable than using loss modulus criterion. Thermal properties of composites are studied by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). Mechanical properties of composites are studied. POLYM. COMPOS., 39:794-806, 2018.

Section: Resultsmentioning

confidence: 87%

Rheology characterization, dynamic mechanical, thermal, and mechanical properties of LGF/TPU/PBT/PTW composites

Qin

et al. 2016

Polymer Composites

“…A similar increase in storage modulus of the polymer composites because of the increasing test frequencies were also reported by some researchers. 21,23,24 From Table 1, the storage modulus of LGF/PBT composites rstly increases and then decreases with the length of the original glass ber increase.…”

Section: Dma Analysis Of Lgf/pbt Compositesmentioning

confidence: 98%

Effect of fiber length and dispersion on properties of long glass fiber reinforced thermoplastic composites based on poly(butylene terephthalate)

Qin

et al. 2017

RSC Adv.

Long glass fiber reinforced poly(butylene terephthalate) (LGF/PBT) composites with different original glass fiber lengths were prepared using a impregnation device designed by the authors. The influence of fiber length and fiber distribution on the properties of the LGF/PBT composites were studied. The results showed that the length of the residual glass fibers increased with the original glass fiber length increase of LGF/PBT composites. Scanning electron microscopy results indicated that the glass fibers of LGF/PBT composites (16 nm and 20 mm) were unevenly dispersed and this is a phenomenon of their reunion in the resin matrix. Various rheological plots including viscosity curve, storage modulus, loss modulus, and loss angle, were used to characterization the rheological properties of the pristine matrix and the LGF/PBT composites. Dynamic mechanical thermal analysis results indicated that the storage and loss modulus of the LGF/PBT composites firstly increase and then decrease with original glass fiber length. The storage and loss modulus, glass transition temperatures of the pristine matrix and LGF/PBT composites increase with test frequencies increase. The activation energies of glass transition relaxation for the activation energies for loss tangent (tan d) and loss modulus (E 00 ) peaks were calculated. Furthermore, the glass transition relaxation determined from the tan d peaks were more reliable than using the E 00 criterion. Differential scanning calorimetry analysis indicated that the crystallization temperature (T c ), percentage crystallinity (X c ) and melting point of the LGF/PBT composites firstly increased and then slightly decreased with the increase of the original glass fiber length. Thermogravimetry (TG) and differential thermal gravimetric analysis curves of the LGF/thermoplastic polyurethane (TPU)/PBT/polyethylene-butylacrylate-glycidyl methacrylate (PTW) composites were shifted to higher temperatures with the increase of the LGF content.Thermogravimetric analysis results showed that the TG curves of the LGF/TPU/PBT/PTW composites firstly shifted to higher temperatures and then shifted to lower temperatures as the original glass fiber length increased. The limiting oxygen values of the pristine matrix and LGF/PBT composites showed little change, which indicated that the effect of the original glass fiber length on the combustion behavior of LGF/PBT composites was not obvious. The tensile strength, notched Izod impact strength, flexural strength and modulus of the LGF/PBT composites firstly increase and then decrease with the original glass fiber length.When the original glass fiber length was 12 mm, the mechanical properties of LGF/PBT composites were optimal.

“…The α-relaxation is related to the Brownian motion of the main chain associated with the glass transition and its relaxation of segments associated with it. In the glass transition region, α-relaxation time of the composites was investigated by measuring at defined frequency response of the composites [16,17]. The temperature dependence of the tan σ determined from the DMA curves of the asprepared LGF/ER/TPU/PMMA composites is shown in Figure 3, when the scanning frequency of the LGF/ER/ TPU/PMMA composites is 1 Hz.…”

Section: Dma Of the Lgf/er/tpu/pmma Compositesmentioning

confidence: 99%

Preparation and properties of LGF/ER/TPU/PMMA composites

Guo

Science and Engineering of Composite Materials

Shao

et al. 2015

A series of long glass fiber (LGF)-reinforced epoxy resin (ER), thermoplastic polyurethane (TPU) elastomers, and poly(methyl methacrylate) (PMMA) composites were prepared by using self-designed impregnation device. Dynamic mechanical properties of the LGF/ER/ TPU/PMMA composites have been investigated by using dynamic mechanical thermal analysis (DMA). The results indicated that the content of PMMA and TPU and scanning frequency had important influence on dynamic mechanical properties and glass transition of the LGF/ER/ TPU/PMMA composites. In addition, the Arrhenius relationship has been used to calculate the activation energy of α-transition of the LGF/ER/TPU/PMMA composites. The thermal properties of the LGF/ER/TPU/PMMA composites were studied by thermogravimetric analysis (TGA). Morphology and mechanical properties of the composites are investigated by scanning electron microscopy (SEM), a universal testing machine, and a ZBC-4 Impact Pendulum.