The Experts below are selected from a list of 7548 Experts worldwide ranked by ideXlab platform

Mojun Liu - One of the best experts on this subject based on the ideXlab platform.

  • morphology effect on water sorption behavior in a thermoplastic modified Epoxy Resin System
    Polymer, 2004
    Co-Authors: Mojun Liu
    Abstract:

    Abstract Water sorption behavior in polyetherimide (PEI) modified diglycidyl ether bisphenol-A/4,4′-diaminodiphenyl sulfone (DGEBA/DDS) Systems was investigated by gravimetric analysis, positron annihilation lifetime spectroscopy and scanning electron microscopy. The equilibrium water uptake showed strong composition-dependent, which suggested that hydrophilic groups rather than free volume were more significant in determining ultimate water sorption. While besides the number of hydrophilic groups and fractional free volume, morphology induced by phase separation was another key factor that decided the value of diffusion coefficient, which was chiefly responsible for the anomalous diffusion behavior observed at the beginning of co-continuous phase. In addition, morphology not only had the function of decreasing fractional free volume, but also changed the number of hydrophilic groups in Epoxy rich regions, which obviously distinguished water sorption behavior in the blends from that in single component Systems.

Jue Cheng - One of the best experts on this subject based on the ideXlab platform.

  • study on curing kinetics of diglycidyl 1 2 cyclohexane dicarboxylate Epoxy episulfide Resin System with hexahydro 4 methylphthalic anhydride as a curing agent
    Journal of Thermal Analysis and Calorimetry, 2015
    Co-Authors: Chongfeng Zhang, Xiaodong Liu, Jue Cheng, Junying Zhang
    Abstract:

    The curing kinetics of the hexahydro-4-methylphthalic anhydride (MHHPA)/diglycidyl 1,2-cyclohexane dicarboxylate (CY184) Epoxy Resin System and MHHPA/CY184 Epoxy/episulfide Resin System (containing 2 mass% DMP-30 as an accelerator) was comparatively investigated by non-isothermal differential scanning calorimetry with a model-fitting Malek method and a model-free advanced isoconversional method of Vyazovkin, and the curing behavior was discussed based on the proposed curing mechanism. The results indicated that both of the MHHPA/CY184 Epoxy Resin System and MHHPA/CY184 Epoxy/episulfide Resin System fitted Sestak–Berggren model. The activation energy of MHHPA/CY184 Epoxy/episulfide Resin System was lower than that of MHHPA/CY184 Epoxy Resin System, suggesting that the episulfide Resin has higher reactivity and can accelerate the reaction. The value of m in the kinetic model equation in MHHPA/CY184 Epoxy/episulfide Resin System is much smaller than that in MHHPA/CY184 Epoxy Resin System, indicating, unlike the MHHPA/CY184 Epoxy Resin System, MHHPA/CY184 Epoxy/episulfide Resin System has much less autocatalytic effect.

  • curing kinetics and shape memory behavior of an intrinsically toughened Epoxy Resin System
    Journal of Thermal Analysis and Calorimetry, 2015
    Co-Authors: Mengjin Fan, Junying Zhang, Jue Cheng
    Abstract:

    A diglycidylether of propoxylated bisphenol-A with two oxypropylene units (DGEBAPO-2) was prepared, and the structure was characterized by FTIR, 1H NMR, and ESI–MS, and a flexible curing agent 2-methyl-1,5-pentanediamine (MPDA) was used to obtain an intrinsically toughened network for potential shape-memory application. The curing kinetics of DGEBAPO-2/MPDA was Systematically investigated by using both non-isothermal and isothermal DSC methods; in addition, the dynamic mechanical property, mechanical property, and shape-memory property were investigated by DMA, tensile experiment, and quantitative shape-memory evaluation method. The results showed that Sestak-Berggren model and Kamal model were able to well describe the non-isothermal curing reaction rate and isothermal curing reaction rate, respectively. Tensile test at 49 °C indicated that the cured DGEBAPO-2/MPDA combined a relatively large elongation at break of 95.53 ± 2.27 % with a relatively large tensile stress of 6.33 ± 0.11 MPa. Quantitative shape-memory evaluation revealed good shape-memory properties of cured DGEBAPO-2/MPDA with shape fixity of 98.88 ± 0.04 % and shape recovery of 96.67 ± 6.91 %.

Colette Lacabanne - One of the best experts on this subject based on the ideXlab platform.

  • Polymerization study and rheological behavior of a RTM6 Epoxy Resin System during preprocessing step
    Journal of Thermal Analysis and Calorimetry, 2015
    Co-Authors: Nicolas Causse, Stephanie Benchimol, Lilian Martineau, Mathieu Fogel, Delphine Carponcin, Jany Dandurand, Antoine Lonjon, Eric Dantras, Colette Lacabanne
    Abstract:

    Curing process and rheological behaviors of a monocomposant Epoxy Resin used in structural aeronautic applications are investigated. This study helped settle the basic parameters in order to optimize the infusion process of carbon fibers in an Epoxy matrix. The effect of carbon nanotube dispersion during the preinjection step is also studied to improve electrical behavior of composite parts. The curing process has been analyzed at isothermal temperature using differential scanning calorimetry technique. Viscosity measurements were achieved with a Couette geometry, suitable for low viscosity Resin. A shear-thinning effect caused by adding CNTs in the Epoxy matrix is detected. It is more pronounced at high temperature for increasing CNT mass content.

G N Dayananda - One of the best experts on this subject based on the ideXlab platform.

  • characterization of shape memory behaviour of ctbn Epoxy Resin System
    Journal of Polymer Research, 2012
    Co-Authors: A Revathi, Sandhya Rao, Shylaja Srihari, G N Dayananda
    Abstract:

    Novel Epoxy based shape memory polymers (SMPs) were prepared by blending bifunctional Epoxy Resin with varying content (0, 5, 10 and 15 wt %) of Carboxyl-Terminated Butadiene Acrylonitrile (CTBN) rubber and cured with a cyclo-aliphatic amine hardener. The Epoxy/CTBN blends were chemically characterized by Epoxy content and gel time measurements. Neat Resin castings were prepared for conducting shape memory tests. The glass transition temperature (Tg) of the test sample was measured in order to fix the deformation temperature (Ttrans). Shape memory (SM) cyclic tests were conducted on both unmodified and CTBN modified Epoxy samples in order to comparatively assess their SM behavior. Compared to unmodified Epoxy SMPs, the CTBN modified Epoxy SMPs exhibited a significant increase in the number of SM cycles, which is attributed to the toughening effect of the CTBN phase.

Mengjin Fan - One of the best experts on this subject based on the ideXlab platform.

  • curing kinetics and shape memory behavior of an intrinsically toughened Epoxy Resin System
    Journal of Thermal Analysis and Calorimetry, 2015
    Co-Authors: Mengjin Fan, Junying Zhang, Jue Cheng
    Abstract:

    A diglycidylether of propoxylated bisphenol-A with two oxypropylene units (DGEBAPO-2) was prepared, and the structure was characterized by FTIR, 1H NMR, and ESI–MS, and a flexible curing agent 2-methyl-1,5-pentanediamine (MPDA) was used to obtain an intrinsically toughened network for potential shape-memory application. The curing kinetics of DGEBAPO-2/MPDA was Systematically investigated by using both non-isothermal and isothermal DSC methods; in addition, the dynamic mechanical property, mechanical property, and shape-memory property were investigated by DMA, tensile experiment, and quantitative shape-memory evaluation method. The results showed that Sestak-Berggren model and Kamal model were able to well describe the non-isothermal curing reaction rate and isothermal curing reaction rate, respectively. Tensile test at 49 °C indicated that the cured DGEBAPO-2/MPDA combined a relatively large elongation at break of 95.53 ± 2.27 % with a relatively large tensile stress of 6.33 ± 0.11 MPa. Quantitative shape-memory evaluation revealed good shape-memory properties of cured DGEBAPO-2/MPDA with shape fixity of 98.88 ± 0.04 % and shape recovery of 96.67 ± 6.91 %.