The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform

Jinming Wang - One of the best experts on this subject based on the ideXlab platform.

  • effect of quantitative characteristic structure of Resole Phenolic prepolymer Resin on thermal stability pyrolysis behaviors and ablation properties
    Journal of Thermal Analysis and Calorimetry, 2021
    Co-Authors: Ying Zhang, Liang Liu, Yunhua Yang, Jinming Wang
    Abstract:

    The chemical structure of Resole Phenolic prepolymer Resin is difficult to be accurately described because it is a mixture composed of different polymerization degree structures. Limited by the knowledge of prepolymer Resin structure, the cross-linking degree (CLD) of cured Resin and the effects of structure on the ablation properties remain unclear. The objective of this work is to understand the relationship between prepolymer Resin structure, CLD of cured Resin, and performance. The quantitative characteristic structure of Resole prepolymer and CLD of curing Resin was proposed in this work based on the full understanding of the chemical structure. A fast and accurate identification method was provided for the quality conformity identification of mass production of Resole prepolymer Phenolic Resin. A novel CLD characterization method for high cross-linking Resole Phenolic Resin was proposed. The results showed that the ablation properties of Resole Phenolic Resin are optimum when formaldehyde/phenol value of prepolymer is in the range of 1.20–1.46. This study may provide meaningful information to the understanding of the ablation mechanism of Resole Phenolic Resin, which is a benefit for developing novel anti-ablation Resin.

Charles U Pittman - One of the best experts on this subject based on the ideXlab platform.

  • Phenolic Resin trisilanolphenyl polyhedral oligomeric silsesquioxane poss hybrid nanocomposites structure and properties
    Polymer, 2006
    Co-Authors: Yudong Zhang, Sang Ho Lee, Mitra Yoonessi, Kaiwen Liang, Charles U Pittman
    Abstract:

    Abstract The structure and properties of organic–inorganic hybrid nanocomposites prepared from a Resole Phenolic Resin and a POSS mixture containing >95 wt% trisilanolphenyl POSS was investigated by POM (polarized optical microscopy), SEM, TEM, WAXD, FT-IR, DSC, and TGA techniques. Composites with 1.0–10.4 wt% of POSS were prepared by dissolving the POSS and the Phenolic Resin into THF, followed by solvent removal and curing. Both nano- and micro-sized POSS filler aggregates and particles were shown to be heterogeneously dispersed in the cured matrix by POM, TEM, SEM, and X-EDS. POSS was found everywhere, including in both dispersed phase domains and in the matrix. The nanocomposite morphology appears to form by a multi-step POSS aggregation during the process of phase separation. Both the matrix and dispersed ‘particulate’ phase domains are mixtures of Phenolic Resin and POSS. POSS micro-crystals act as the core of the dispersed phase. The bigger dispersed domains consist of smaller particles or aggregates of POSS molecules that exhibit some order but regions of matrix Resin are interspersed. A WAXD peak at 2θ∼7.3° indicates crystalline order in the POSS aggregates. This characteristic peak's intensity increases with an increase in POSS loading, suggesting that more POSS molecules have aggregated or crystallized. FT-IR spectra confirm that hydrogen bonding exists between the Phenolic Resin and POSS Si–OH groups. This increases their mutual compatibility, but H-bonding does not prevent POSS aggregation and phase separation during curing. TGA measurements in air confirmed the temperature for 5% mass loss in increases with increase of POSS loading and at T>550° the thermal stability increases more sharply with POSS loading. The nanocomposite glass transition temperatures (Tg) are only slightly be affected by the POSS filler.

Ying Zhang - One of the best experts on this subject based on the ideXlab platform.

  • effect of quantitative characteristic structure of Resole Phenolic prepolymer Resin on thermal stability pyrolysis behaviors and ablation properties
    Journal of Thermal Analysis and Calorimetry, 2021
    Co-Authors: Ying Zhang, Liang Liu, Yunhua Yang, Jinming Wang
    Abstract:

    The chemical structure of Resole Phenolic prepolymer Resin is difficult to be accurately described because it is a mixture composed of different polymerization degree structures. Limited by the knowledge of prepolymer Resin structure, the cross-linking degree (CLD) of cured Resin and the effects of structure on the ablation properties remain unclear. The objective of this work is to understand the relationship between prepolymer Resin structure, CLD of cured Resin, and performance. The quantitative characteristic structure of Resole prepolymer and CLD of curing Resin was proposed in this work based on the full understanding of the chemical structure. A fast and accurate identification method was provided for the quality conformity identification of mass production of Resole prepolymer Phenolic Resin. A novel CLD characterization method for high cross-linking Resole Phenolic Resin was proposed. The results showed that the ablation properties of Resole Phenolic Resin are optimum when formaldehyde/phenol value of prepolymer is in the range of 1.20–1.46. This study may provide meaningful information to the understanding of the ablation mechanism of Resole Phenolic Resin, which is a benefit for developing novel anti-ablation Resin.

Yudong Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Phenolic Resin trisilanolphenyl polyhedral oligomeric silsesquioxane poss hybrid nanocomposites structure and properties
    Polymer, 2006
    Co-Authors: Yudong Zhang, Sang Ho Lee, Mitra Yoonessi, Kaiwen Liang, Charles U Pittman
    Abstract:

    Abstract The structure and properties of organic–inorganic hybrid nanocomposites prepared from a Resole Phenolic Resin and a POSS mixture containing >95 wt% trisilanolphenyl POSS was investigated by POM (polarized optical microscopy), SEM, TEM, WAXD, FT-IR, DSC, and TGA techniques. Composites with 1.0–10.4 wt% of POSS were prepared by dissolving the POSS and the Phenolic Resin into THF, followed by solvent removal and curing. Both nano- and micro-sized POSS filler aggregates and particles were shown to be heterogeneously dispersed in the cured matrix by POM, TEM, SEM, and X-EDS. POSS was found everywhere, including in both dispersed phase domains and in the matrix. The nanocomposite morphology appears to form by a multi-step POSS aggregation during the process of phase separation. Both the matrix and dispersed ‘particulate’ phase domains are mixtures of Phenolic Resin and POSS. POSS micro-crystals act as the core of the dispersed phase. The bigger dispersed domains consist of smaller particles or aggregates of POSS molecules that exhibit some order but regions of matrix Resin are interspersed. A WAXD peak at 2θ∼7.3° indicates crystalline order in the POSS aggregates. This characteristic peak's intensity increases with an increase in POSS loading, suggesting that more POSS molecules have aggregated or crystallized. FT-IR spectra confirm that hydrogen bonding exists between the Phenolic Resin and POSS Si–OH groups. This increases their mutual compatibility, but H-bonding does not prevent POSS aggregation and phase separation during curing. TGA measurements in air confirmed the temperature for 5% mass loss in increases with increase of POSS loading and at T>550° the thermal stability increases more sharply with POSS loading. The nanocomposite glass transition temperatures (Tg) are only slightly be affected by the POSS filler.

Liang Guozheng - One of the best experts on this subject based on the ideXlab platform.

  • effect of different catalysts on the structure and properties of Resole Phenolic Resin
    Thermosetting Resin, 2011
    Co-Authors: Liang Guozheng
    Abstract:

    The three Resole Phenolic Resins were synthesized using ammonia,triethylamine and sodium hydroxide as catalyst,respectively.The catalytic reaction mechanism of three catalysts and the effect of different catalysts on the molecular weight and its distribution and the Resin structure were investigated by the testing of pH value,gel chromatography and infrared spectroscopy.The Phenolic Resin laminates were prepared from three Resole Resins using dipping and hot pressing process and the bending properties of the laminates were tested.The results showed that the catalytic efficiency was NaOH triethylamine ammonia.The Resins catalyzed with different catalysts had similar chemical structure.The laminate based on the triethylamine catalyzed Resin had the best processing characteristics and mechanical properties.