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Chenchi M - One of the best experts on this subject based on the ideXlab platform.

  • preparation and characterization of novolac type Phenolic Resin blended with poly dimethylsiloxane adipamide
    Journal of Applied Polymer Science, 2002
    Co-Authors: Albert Y Hung, Fengyih Wang, Chenchi M, Yihmin Sun
    Abstract:

    Phenolic Resin/poly(dimethylsiloxane adipamide) (PDMSA) blends, which have been prepared, show miscibility due to intermolecular H-bonding existing between Phenolic Resin and the PDMSA. The specific H-bonding of novolac type Phenolic/PDMSA blends was characterized by means of glass transition temperature behavior and Fourier Transform Infrared Spectroscopy (FTIR). The strength of intermolecular H-bonding within the Phenolic blend is a function of the H-bonded group of the PDMSA modifier and corresponds to the deviation glass transition temperature (ΔTg). Phenolic/PDMSA blends were completely miscible, as confirmed by the Tg study. The FTIR result is in good agreement with the inference from Tg behavior. The char yield of Phenolic/PDMSA corresponds to the Phenolic Resin content. The molecular mobility of Phenolic/PDMSA blends increases with PDMSA content in the Phenolic-rich region. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 984–992, 2002

  • carbon carbon composites derived from poly ethylene oxide modified novolac type Phenolic Resin microstructure and physical and morphological properties
    Journal of Applied Polymer Science, 2002
    Co-Authors: Albert Y Hung, Fengyih Wang, Shangru Yeh, Weijen Chen, Chenchi M
    Abstract:

    A poly(ethylene oxide) (PEO) novolac-type Phenolic Resin blend was prepared by the physical blending method. The modified novolac-type Phenolic Resin with various PEO contents was used as a matrix precursor to fabricate carbon/carbon composites. The effect of the PEO/Phenolic Resin mixing ratio on the change of the density and of the porosity was studied. The flexural strength and interlaminar shear strength of the PEO/Phenolic Resin blend-derived carbon/carbon composites were also investigated. The results show that the density of the PEO/Phenolic Resin blend-derived carbon/carbon composites decreases with the PEO content. The X-ray diffraction and Raman spectra studies showed that the carbon fiber in the samples will affect the growth of the ordered carbon structure. From SEM morphological observation, it is shown that the fracture surface of specimens is smooth. Also, there is less fiber pull-out and fiber breakage on the fracture surface.

  • thermal mechanical and morphological properties of novolac type Phenolic Resin blended with fullerenol polyurethane and linear polyurethane
    Journal of Polymer Science Part B, 2001
    Co-Authors: Chenchi M, Fengyih Wang, Shangchin Sung, Long Y Chiang, Lee Y Wang, Chinlung Chiang
    Abstract:

    Fullerenol polyurethane (C60-PU) and linear polyurethane (linear-PU) modified Phenolic Resins were prepared in this study. Phenolic Resin/C60-PU and Phenolic Resin/linear-PU blends show good miscibility as a result of the intermolecular hydrogen bonding existing between Phenolic Resin and PU modifiers. DSC and thermogravimetric analysis methods were used to study the thermal properties of Phenolic Resin blended with different types of PUs. The intermolecular hydrogen bonding that existed between Phenolic Resin and C60-PU was investigated by Fourier transform infrared spectroscopy. The morphology and mechanical properties of Phenolic Resin/C60-PU and Phenolic Resin/linear-PU blends were also investigated. The char yield of the modified Phenolic Resins decreased with increasing PU modifier content. Significant improvement in the toughness of the modified Phenolic Resins was observed. The improvements of impact strength were 27.4% for the Phenolic Resin/linear-PU system and 54.3% for the Phenolic Resin/C60-PU system, respectively, both with 3 phr linear-PU and C60-PU content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2436–2443, 2001

  • kinetic parameters of thermal degradation of polyethylene glycol toughened novolac type Phenolic Resin
    Journal of Applied Polymer Science, 2001
    Co-Authors: Fengyih Wang, Chenchi M
    Abstract:

    The miscibility and thermal degradation of poly(ethylene glycol) (PEG)-toughened novolac-type Phenolic Resin were investigated. Differential scanning calorimetry (DSC) results confirmed that the Phenolic Resin/PEG blend was blended completely. Infrared spectra show that hydrogen bonding existed in the blends. Thermal degradation of PEG blended with novolac-type Phenolic Resin was studied utilizing a dynamic thermogravimetric technique in a flowing nitrogen atmosphere at several heating rates (i.e., 5, 10, 20, 40°C/min). Thermal degradation of Phenolic Resin/PEG blends takes place in multiple steps. The thermal behavior and the thermal stability affected the thermal degradation, which coincided with the data from the thermal degradation of novolac-type Phenolic Resin/PEG blends by thermogravimetric analysis (TGA).

  • thermal degradation of polyethylene oxide blended with novolac type Phenolic Resin
    Journal of Materials Science, 2001
    Co-Authors: Fengyih Wang, Chenchi M
    Abstract:

    The miscibility and thermal degradation of poly(ethylene oxide) (PEO) toughened novolac type Phenolic Resin were investigated. Differential scanning calorimetry (DSC) results confirmed that Phenolic Resin/PEO blend was blended completely. Infrared spectra show that hydrogen bonding existed in the blends. Thermal degradation of poly(ethylene oxide) blended with novolac type Phenolic Resin has been studied utilizing a dynamic thermogravimetric technique in a flowing nitrogen atmosphere at several heating rates (i.e. 5, 10, 20, 40°C/min). Thermal degradation of Phenolic Resin/PEO blends takes place in multiple steps. Chemical structure and components of blends affected thermal degradation, which coincided with the data from thermal degradation of novolac type Phenolic Resin/PEO blends by thermogravimetric analysis (TGA).

In Jae Chung - One of the best experts on this subject based on the ideXlab platform.

  • mechanical and thermal properties of Phenolic Resin layered silicate nanocomposites synthesized by melt intercalation
    Journal of Applied Polymer Science, 2003
    Co-Authors: Min Ho Choi, In Jae Chung
    Abstract:

    Phenolic Resin–layered silicate nanocomposites (PLSNs) were synthesized by melt intercalation with linear novolac Resin (P1) and organosilicates such as montmorillonite modified by benzyldimethyloctadecylammonium (C18BM) and by bis(2-hydroxy-ethyl)methyl tallow ammonium (THEM). The PLSNs were prepared by a sequential process (IC) in which Phenolic Resin was melt-intercalated into organosilicate and subsequently cured with hexamethylenetetramine (HMTA). It was found from X-ray diffraction measurements that P1THEMIC nanocomposites showed better silicate dispersion than did P1C18BMIC nanocomposites, even though both systems had intercalated morphologies. The larger silicate gallery expansion in P1THEMIC nanocomposites was attributed to the strong hydrogen-bonding interaction between the Phenolic Resin and hydroxyl groups of the organic modifier of THEM. As they had better silicate dispersion, the P1THEMIC nanocomposites showed better mechanical properties than the P1C18BMIC nanocomposites. The thermal stability of the P1THEMIC nanocomposites was slightly increased or decreased, depending on the silicate content, relative to the neat Phenolic Resin. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2316–2321, 2003

  • synthesis and characterization of resol type Phenolic Resin layered silicate nanocomposites
    Chemistry of Materials, 2001
    Co-Authors: Ho Yun Byun, Min Ho Choi, In Jae Chung
    Abstract:

    Resol type Phenolic Resin/layered silicate nanocomposites (RPLSNs) are prepared by melt intercalation using various layered silicates such as sodium montmorillonite (MMT) and ω-amino acid modified montmorillonites (C3M, C6M, and C12M). The most hydrophilic MMT is the most compatible with the resol type Phenolic Resin (KL) at the beginning of cure due to the initial hydrophilicity of KL with many methylol groups. However, KL is deintercalated out of extragallery of MMT during the cure since the KL lose hydrophilicity by the depletion of methylol groups. It is found that the C6M has the best miscibility with KL at the entire cure stage. The KLC6M system has the best mechanical properties, due to the end-tethered structure formed by the reaction between the organic modifier (carboxylic acid) of C6M and the methylol group of KL, as well as the excellent dispersion of silicate layers. RPLSNs have similar thermal stability to the neat Phenolic Resin.

  • morphology and curing behaviors of Phenolic Resin layered silicate nanocomposites prepared by melt intercalation
    Chemistry of Materials, 2000
    Co-Authors: Min Ho Choi, In Jae Chung, Jong Doo Lee
    Abstract:

    The melt intercalation and curing behavior of Phenolic Resin (P1) were investigated by use of layered silicates, such as pristine montmorillonite (PM), dodecylammonium-modified montmorillonite (C12M), octadecylammonium-modified montmorillonite (C18M), benzyldimethyloctadecylammonium-modified fluorohectorite (C18BH), and hexamethylenetetramine (HMTA), as curing agents. It was found by X-ray diffraction that the uncured Phenolic Resin was intercalated into PM, C18M, and C18BH. Cured Phenolic Resin-layered silicate nanocomposites were prepared by two methods:  one was the sequential process of intercalation and curing (IC, the suffix of sample code), and the other was the simultaneous process of mixing and curing (MC). The intercalated structures were preserved in cured P1C18BH but not in cured P1C18M, i.e., the Phenolic Resin intercalated in C18M was deintercalated when it was cured. It was suggested that the intercalated structure of P1C18BH was more stable in the curing process than that of P1C18M due to ...

  • the effect of coupling agent on electrical and mechanical properties of carbon fiber Phenolic Resin composites
    Polymer, 2000
    Co-Authors: Min Ho Choi, Byoung Ho Jeon, In Jae Chung
    Abstract:

    Abstract Carbon fiber/Phenolic Resin composites were prepared by changing the content (5–10 wt%) of short carbon fibers. To investigate the effect of carbon fiber treatment on the electrical and mechanical properties of the composites, three specimens were prepared: the short carbon fiber treated to remove size (called USCF); the carbon fiber oxidized with nitric acid (called NAOCF); and the fiber oxidized with nitric acid and treated with coupling agent glutaric dialdehyde (called GTDACF). The GTDACF composite had higher electrical conductivity and better mechanical property than the other composites with the same content of carbon fibers. The surface treatment methods affected the dielectric behaviors of the composites with short carbon fibers while they did not affect those of the composites with fabric type carbon fibers. From these observations, the coupling agent improved adhesion between the carbon fiber and the Phenolic Resin by forming a chemical bond between fiber and Resin. The coupling agent also affected the flow and dispersion of the short carbon fiber in the Phenolic Resin during compression molding, resulting in the higher electrical conductivity and better mechanical property of GTDACF composite.

Min Ho Choi - One of the best experts on this subject based on the ideXlab platform.

  • mechanical and thermal properties of Phenolic Resin layered silicate nanocomposites synthesized by melt intercalation
    Journal of Applied Polymer Science, 2003
    Co-Authors: Min Ho Choi, In Jae Chung
    Abstract:

    Phenolic Resin–layered silicate nanocomposites (PLSNs) were synthesized by melt intercalation with linear novolac Resin (P1) and organosilicates such as montmorillonite modified by benzyldimethyloctadecylammonium (C18BM) and by bis(2-hydroxy-ethyl)methyl tallow ammonium (THEM). The PLSNs were prepared by a sequential process (IC) in which Phenolic Resin was melt-intercalated into organosilicate and subsequently cured with hexamethylenetetramine (HMTA). It was found from X-ray diffraction measurements that P1THEMIC nanocomposites showed better silicate dispersion than did P1C18BMIC nanocomposites, even though both systems had intercalated morphologies. The larger silicate gallery expansion in P1THEMIC nanocomposites was attributed to the strong hydrogen-bonding interaction between the Phenolic Resin and hydroxyl groups of the organic modifier of THEM. As they had better silicate dispersion, the P1THEMIC nanocomposites showed better mechanical properties than the P1C18BMIC nanocomposites. The thermal stability of the P1THEMIC nanocomposites was slightly increased or decreased, depending on the silicate content, relative to the neat Phenolic Resin. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2316–2321, 2003

  • synthesis and characterization of resol type Phenolic Resin layered silicate nanocomposites
    Chemistry of Materials, 2001
    Co-Authors: Ho Yun Byun, Min Ho Choi, In Jae Chung
    Abstract:

    Resol type Phenolic Resin/layered silicate nanocomposites (RPLSNs) are prepared by melt intercalation using various layered silicates such as sodium montmorillonite (MMT) and ω-amino acid modified montmorillonites (C3M, C6M, and C12M). The most hydrophilic MMT is the most compatible with the resol type Phenolic Resin (KL) at the beginning of cure due to the initial hydrophilicity of KL with many methylol groups. However, KL is deintercalated out of extragallery of MMT during the cure since the KL lose hydrophilicity by the depletion of methylol groups. It is found that the C6M has the best miscibility with KL at the entire cure stage. The KLC6M system has the best mechanical properties, due to the end-tethered structure formed by the reaction between the organic modifier (carboxylic acid) of C6M and the methylol group of KL, as well as the excellent dispersion of silicate layers. RPLSNs have similar thermal stability to the neat Phenolic Resin.

  • morphology and curing behaviors of Phenolic Resin layered silicate nanocomposites prepared by melt intercalation
    Chemistry of Materials, 2000
    Co-Authors: Min Ho Choi, In Jae Chung, Jong Doo Lee
    Abstract:

    The melt intercalation and curing behavior of Phenolic Resin (P1) were investigated by use of layered silicates, such as pristine montmorillonite (PM), dodecylammonium-modified montmorillonite (C12M), octadecylammonium-modified montmorillonite (C18M), benzyldimethyloctadecylammonium-modified fluorohectorite (C18BH), and hexamethylenetetramine (HMTA), as curing agents. It was found by X-ray diffraction that the uncured Phenolic Resin was intercalated into PM, C18M, and C18BH. Cured Phenolic Resin-layered silicate nanocomposites were prepared by two methods:  one was the sequential process of intercalation and curing (IC, the suffix of sample code), and the other was the simultaneous process of mixing and curing (MC). The intercalated structures were preserved in cured P1C18BH but not in cured P1C18M, i.e., the Phenolic Resin intercalated in C18M was deintercalated when it was cured. It was suggested that the intercalated structure of P1C18BH was more stable in the curing process than that of P1C18M due to ...

  • the effect of coupling agent on electrical and mechanical properties of carbon fiber Phenolic Resin composites
    Polymer, 2000
    Co-Authors: Min Ho Choi, Byoung Ho Jeon, In Jae Chung
    Abstract:

    Abstract Carbon fiber/Phenolic Resin composites were prepared by changing the content (5–10 wt%) of short carbon fibers. To investigate the effect of carbon fiber treatment on the electrical and mechanical properties of the composites, three specimens were prepared: the short carbon fiber treated to remove size (called USCF); the carbon fiber oxidized with nitric acid (called NAOCF); and the fiber oxidized with nitric acid and treated with coupling agent glutaric dialdehyde (called GTDACF). The GTDACF composite had higher electrical conductivity and better mechanical property than the other composites with the same content of carbon fibers. The surface treatment methods affected the dielectric behaviors of the composites with short carbon fibers while they did not affect those of the composites with fabric type carbon fibers. From these observations, the coupling agent improved adhesion between the carbon fiber and the Phenolic Resin by forming a chemical bond between fiber and Resin. The coupling agent also affected the flow and dispersion of the short carbon fiber in the Phenolic Resin during compression molding, resulting in the higher electrical conductivity and better mechanical property of GTDACF composite.

Antonio B Fuertes - One of the best experts on this subject based on the ideXlab platform.

  • effects of Phenolic Resin pyrolysis conditions on carbon membrane performance for gas separation
    Journal of Membrane Science, 2004
    Co-Authors: Teresa A Centeno, J L Vilas, Antonio B Fuertes
    Abstract:

    Abstract This work shows that the gas separation performance of Phenolic Resin-based carbon membranes can be adjusted by controlling the pyrolysis processing variables (heat treatment temperature, heating rate, soaking time and atmosphere). A large variety of carbon membranes for gas separation have been developed by simple carbonization of a Phenolic Resin film deposited on a ceramic tubular support. Thus, molecular sieve carbon membranes (MSCMs) with good capabilities towards the separation of O 2 –N 2 , CO 2 –CH 4 , CO 2 –N 2 and olefin–paraffin mixtures as well as adsorption-selective carbon membranes (ASCMs) effective in the recovery of hydrocarbons from hydrocarbon–N 2 mixtures have been obtained.

  • carbon molecular sieve membranes derived from a Phenolic Resin supported on porous ceramic tubes
    Separation and Purification Technology, 2001
    Co-Authors: Teresa A Centeno, Antonio B Fuertes
    Abstract:

    The preparation of a composite carbon membrane from a Phenolic Resin is described. The membrane is formed by a thin microporous carbon layer (thickness: 2 μm) obtained by pyrolysis (700°C, under vacuum) of a Phenolic Resin film supported on the inner face of a porous alumina tube. The separation characteristics of the resulting carbon membranes were analysed from permeation experiments with pure gases of different molecular size (He, CO2, O2, N2 and CH4) and separation of binary gas mixtures O2–N2 and CO2–CH4. An almost defect-free carbon membrane is obtained in only one casting step. The effective micropore size was estimated to be around 4.4 A. The prepared carbon membranes have demonstrated to be effective for separating gas mixtures such as O2–N2 (O2 permeance: 100 Barrer; O2–N2 separation factor: 12) and CO2–CH4 (CO2 permeance: 400 Barrer; CO2–CH4 separation factor: 150). The oxidation of the Phenolic Resin film with air at temperatures ranging from 150 to 300°C improves the gas permeance and originates a decrease in the permselectivity.

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

  • preparation and characterization of novolac type Phenolic Resin blended with poly dimethylsiloxane adipamide
    Journal of Applied Polymer Science, 2002
    Co-Authors: Albert Y Hung, Fengyih Wang, Chenchi M, Yihmin Sun
    Abstract:

    Phenolic Resin/poly(dimethylsiloxane adipamide) (PDMSA) blends, which have been prepared, show miscibility due to intermolecular H-bonding existing between Phenolic Resin and the PDMSA. The specific H-bonding of novolac type Phenolic/PDMSA blends was characterized by means of glass transition temperature behavior and Fourier Transform Infrared Spectroscopy (FTIR). The strength of intermolecular H-bonding within the Phenolic blend is a function of the H-bonded group of the PDMSA modifier and corresponds to the deviation glass transition temperature (ΔTg). Phenolic/PDMSA blends were completely miscible, as confirmed by the Tg study. The FTIR result is in good agreement with the inference from Tg behavior. The char yield of Phenolic/PDMSA corresponds to the Phenolic Resin content. The molecular mobility of Phenolic/PDMSA blends increases with PDMSA content in the Phenolic-rich region. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 984–992, 2002

  • carbon carbon composites derived from poly ethylene oxide modified novolac type Phenolic Resin microstructure and physical and morphological properties
    Journal of Applied Polymer Science, 2002
    Co-Authors: Albert Y Hung, Fengyih Wang, Shangru Yeh, Weijen Chen, Chenchi M
    Abstract:

    A poly(ethylene oxide) (PEO) novolac-type Phenolic Resin blend was prepared by the physical blending method. The modified novolac-type Phenolic Resin with various PEO contents was used as a matrix precursor to fabricate carbon/carbon composites. The effect of the PEO/Phenolic Resin mixing ratio on the change of the density and of the porosity was studied. The flexural strength and interlaminar shear strength of the PEO/Phenolic Resin blend-derived carbon/carbon composites were also investigated. The results show that the density of the PEO/Phenolic Resin blend-derived carbon/carbon composites decreases with the PEO content. The X-ray diffraction and Raman spectra studies showed that the carbon fiber in the samples will affect the growth of the ordered carbon structure. From SEM morphological observation, it is shown that the fracture surface of specimens is smooth. Also, there is less fiber pull-out and fiber breakage on the fracture surface.

  • thermal mechanical and morphological properties of novolac type Phenolic Resin blended with fullerenol polyurethane and linear polyurethane
    Journal of Polymer Science Part B, 2001
    Co-Authors: Chenchi M, Fengyih Wang, Shangchin Sung, Long Y Chiang, Lee Y Wang, Chinlung Chiang
    Abstract:

    Fullerenol polyurethane (C60-PU) and linear polyurethane (linear-PU) modified Phenolic Resins were prepared in this study. Phenolic Resin/C60-PU and Phenolic Resin/linear-PU blends show good miscibility as a result of the intermolecular hydrogen bonding existing between Phenolic Resin and PU modifiers. DSC and thermogravimetric analysis methods were used to study the thermal properties of Phenolic Resin blended with different types of PUs. The intermolecular hydrogen bonding that existed between Phenolic Resin and C60-PU was investigated by Fourier transform infrared spectroscopy. The morphology and mechanical properties of Phenolic Resin/C60-PU and Phenolic Resin/linear-PU blends were also investigated. The char yield of the modified Phenolic Resins decreased with increasing PU modifier content. Significant improvement in the toughness of the modified Phenolic Resins was observed. The improvements of impact strength were 27.4% for the Phenolic Resin/linear-PU system and 54.3% for the Phenolic Resin/C60-PU system, respectively, both with 3 phr linear-PU and C60-PU content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2436–2443, 2001

  • kinetic parameters of thermal degradation of polyethylene glycol toughened novolac type Phenolic Resin
    Journal of Applied Polymer Science, 2001
    Co-Authors: Fengyih Wang, Chenchi M
    Abstract:

    The miscibility and thermal degradation of poly(ethylene glycol) (PEG)-toughened novolac-type Phenolic Resin were investigated. Differential scanning calorimetry (DSC) results confirmed that the Phenolic Resin/PEG blend was blended completely. Infrared spectra show that hydrogen bonding existed in the blends. Thermal degradation of PEG blended with novolac-type Phenolic Resin was studied utilizing a dynamic thermogravimetric technique in a flowing nitrogen atmosphere at several heating rates (i.e., 5, 10, 20, 40°C/min). Thermal degradation of Phenolic Resin/PEG blends takes place in multiple steps. The thermal behavior and the thermal stability affected the thermal degradation, which coincided with the data from the thermal degradation of novolac-type Phenolic Resin/PEG blends by thermogravimetric analysis (TGA).

  • thermal degradation of polyethylene oxide blended with novolac type Phenolic Resin
    Journal of Materials Science, 2001
    Co-Authors: Fengyih Wang, Chenchi M
    Abstract:

    The miscibility and thermal degradation of poly(ethylene oxide) (PEO) toughened novolac type Phenolic Resin were investigated. Differential scanning calorimetry (DSC) results confirmed that Phenolic Resin/PEO blend was blended completely. Infrared spectra show that hydrogen bonding existed in the blends. Thermal degradation of poly(ethylene oxide) blended with novolac type Phenolic Resin has been studied utilizing a dynamic thermogravimetric technique in a flowing nitrogen atmosphere at several heating rates (i.e. 5, 10, 20, 40°C/min). Thermal degradation of Phenolic Resin/PEO blends takes place in multiple steps. Chemical structure and components of blends affected thermal degradation, which coincided with the data from thermal degradation of novolac type Phenolic Resin/PEO blends by thermogravimetric analysis (TGA).