The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Chi-min Shu - One of the best experts on this subject based on the ideXlab platform.

  • thermal hazard evaluation of the autocatalytic reaction of Benzoyl Peroxide using dsc and tam iii
    Thermochimica Acta, 2015
    Co-Authors: Shanghao Liu, Hungyi Hou, Chi-min Shu
    Abstract:

    Abstract A new approach was used to monitor the autocatalytic reaction of Benzoyl Peroxide (BPO) by non-isothermal and isothermal kinetic models constructed using differential scanning calorimetry and thermal activity monitor III analyses, respectively. Autocatalytic reactions generally start slowly and then accelerate as the reactant is consumed and the autocatalyst is produced. Consequently, an autocatalytic reaction may require special design considerations to avoid certain upset conditions, such as runaway exothermic reactions. We conducted a thermal hazard analysis of various products, including benzoic acid, benzene, and phenol, which were deliberately selected and individually mixed with BPO to investigate their thermal hazards. Model fitting can be applied to predict the amount of time required to achieve the maximum rate under isothermal conditions at any temperature of interest. The proposed procedure was effective and accurate for evaluating the autocatalytic reaction of BPO.

  • Simulation approach to Benzoyl Peroxide decomposition kinetics by thermal calorimetric technique
    Journal of The Taiwan Institute of Chemical Engineers, 2013
    Co-Authors: Ming-hsun Lee, Jiann-rong Chen, Gong-yih Shiue, Yan-fu Lin, Chi-min Shu
    Abstract:

    Abstract To explore the thermal runaway behavior of Benzoyl Peroxide (BPO) in industrial processes during upsets situations and to compare the difference of values between simulation and experimentation, two calorimeters, differential scanning calorimetry (DSC) and vent sizing package 2 (VSP2), were employed to measure thermokinetic data of the thermal decomposition of BPO, and to calculate values of parameters by simulation approach, which were based on kinetic models and the thermal safety software. This study shows the novel finding that Benzoyl Peroxide (BPO) has an autocatalytic reaction at low temperature. The simulation results showed that the E a value was 124 kJ/mol by VSP2 tests. The E a value was much closer to Zaman's studies than the E a values developed by the Kissinger and/or Ozawa methods. The E a value resulting from the optimal fit approach average was 91.47 ± 17.69 kJ/mol also closer to Zaman's studies than values from the Kissinger and Ozawa methods.

  • isothermal hazards evaluation of Benzoyl Peroxide mixed with benzoic acid via tam iii test
    Journal of Thermal Analysis and Calorimetry, 2013
    Co-Authors: Tienszu Wang, Shanghao Liu, Xinming Qian, Meili You, Weilung Chou, Chi-min Shu
    Abstract:

    Isothermal microcalorimetry can be used to investigate the thermokinetic parameters for reactive mechanisms. Benzoyl Peroxide (BPO), a typical organic Peroxide, undergoes an autocatalytic reaction under isothermal decomposition. It requires intrinsically safer design of preparation, manufacturing, transportation, storage, and even disposal. The scope of this study was to describe the exothermic reaction and reaction model of BPO and mixed with benzoic acid by the thermal activity monitor III (TAM III). The results showed the isothermal kinetic parameters, such as activation energy (E a), frequency factor (A), heat of decomposition (ΔH d), and time to maximum rate under isothermal conditions (TMR iso), which were necessary and useful to insure safe storage or transportation for self-reactive substances applied in the process industries.

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

  • ester functionalization of polypropylene via controlled decomposition of Benzoyl Peroxide during solid state shear pulverization
    Macromolecules, 2013
    Co-Authors: Mirian F Diop, John M Torkelson
    Abstract:

    Polypropylene (PP) is a nonpolar polyolefin that is sometimes functionalized with polar molecules to allow for reactive compatibilization and improve interfacial adhesion. Functionalized PP is conventionally synthesized by melt extrusion at elevated temperature (T) (≥∼180 °C) with a radical initiator and polar monomer, e.g., maleic anhydride. A drawback to high T functionalization is that β-scission, which leads to cleavage of C–C backbone bonds, is significant and results in major molecular weight (MW) reduction and property degradation. We present a novel method of functionalizing PP using Benzoyl Peroxide (BPO) alone by a process called solid-state shear pulverization (SSSP), resulting in ester functional groups (benzoates) grafted at high yield onto PP. Ester functionalized PP (PP-g-ES) is synthesized with limited MW reduction because SSSP is done at sufficiently low T to suppress β-scission. Characterization before and after grafting at 0.18 mol % (0.46 wt %) graft level indicates that functionalizat...

  • ester functionalization of polypropylene via controlled decomposition of Benzoyl Peroxide during solid state shear pulverization
    Macromolecules, 2013
    Co-Authors: Mirian F Diop, John M Torkelson
    Abstract:

    Polypropylene (PP) is a nonpolar polyolefin that is sometimes functionalized with polar molecules to allow for reactive compatibilization and improve interfacial adhesion. Functionalized PP is conventionally synthesized by melt extrusion at elevated temperature (T) (≥∼180 °C) with a radical initiator and polar monomer, e.g., maleic anhydride. A drawback to high T functionalization is that β-scission, which leads to cleavage of C–C backbone bonds, is significant and results in major molecular weight (MW) reduction and property degradation. We present a novel method of functionalizing PP using Benzoyl Peroxide (BPO) alone by a process called solid-state shear pulverization (SSSP), resulting in ester functional groups (benzoates) grafted at high yield onto PP. Ester functionalized PP (PP-g-ES) is synthesized with limited MW reduction because SSSP is done at sufficiently low T to suppress β-scission. Characterization before and after grafting at 0.18 mol % (0.46 wt %) graft level indicates that functionalizat...

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

  • thermal hazard evaluation of the autocatalytic reaction of Benzoyl Peroxide using dsc and tam iii
    Thermochimica Acta, 2015
    Co-Authors: Shanghao Liu, Hungyi Hou, Chi-min Shu
    Abstract:

    Abstract A new approach was used to monitor the autocatalytic reaction of Benzoyl Peroxide (BPO) by non-isothermal and isothermal kinetic models constructed using differential scanning calorimetry and thermal activity monitor III analyses, respectively. Autocatalytic reactions generally start slowly and then accelerate as the reactant is consumed and the autocatalyst is produced. Consequently, an autocatalytic reaction may require special design considerations to avoid certain upset conditions, such as runaway exothermic reactions. We conducted a thermal hazard analysis of various products, including benzoic acid, benzene, and phenol, which were deliberately selected and individually mixed with BPO to investigate their thermal hazards. Model fitting can be applied to predict the amount of time required to achieve the maximum rate under isothermal conditions at any temperature of interest. The proposed procedure was effective and accurate for evaluating the autocatalytic reaction of BPO.

  • isothermal hazards evaluation of Benzoyl Peroxide mixed with benzoic acid via tam iii test
    Journal of Thermal Analysis and Calorimetry, 2013
    Co-Authors: Tienszu Wang, Shanghao Liu, Xinming Qian, Meili You, Weilung Chou, Chi-min Shu
    Abstract:

    Isothermal microcalorimetry can be used to investigate the thermokinetic parameters for reactive mechanisms. Benzoyl Peroxide (BPO), a typical organic Peroxide, undergoes an autocatalytic reaction under isothermal decomposition. It requires intrinsically safer design of preparation, manufacturing, transportation, storage, and even disposal. The scope of this study was to describe the exothermic reaction and reaction model of BPO and mixed with benzoic acid by the thermal activity monitor III (TAM III). The results showed the isothermal kinetic parameters, such as activation energy (E a), frequency factor (A), heat of decomposition (ΔH d), and time to maximum rate under isothermal conditions (TMR iso), which were necessary and useful to insure safe storage or transportation for self-reactive substances applied in the process industries.

Mirian F Diop - One of the best experts on this subject based on the ideXlab platform.

  • ester functionalization of polypropylene via controlled decomposition of Benzoyl Peroxide during solid state shear pulverization
    Macromolecules, 2013
    Co-Authors: Mirian F Diop, John M Torkelson
    Abstract:

    Polypropylene (PP) is a nonpolar polyolefin that is sometimes functionalized with polar molecules to allow for reactive compatibilization and improve interfacial adhesion. Functionalized PP is conventionally synthesized by melt extrusion at elevated temperature (T) (≥∼180 °C) with a radical initiator and polar monomer, e.g., maleic anhydride. A drawback to high T functionalization is that β-scission, which leads to cleavage of C–C backbone bonds, is significant and results in major molecular weight (MW) reduction and property degradation. We present a novel method of functionalizing PP using Benzoyl Peroxide (BPO) alone by a process called solid-state shear pulverization (SSSP), resulting in ester functional groups (benzoates) grafted at high yield onto PP. Ester functionalized PP (PP-g-ES) is synthesized with limited MW reduction because SSSP is done at sufficiently low T to suppress β-scission. Characterization before and after grafting at 0.18 mol % (0.46 wt %) graft level indicates that functionalizat...

  • ester functionalization of polypropylene via controlled decomposition of Benzoyl Peroxide during solid state shear pulverization
    Macromolecules, 2013
    Co-Authors: Mirian F Diop, John M Torkelson
    Abstract:

    Polypropylene (PP) is a nonpolar polyolefin that is sometimes functionalized with polar molecules to allow for reactive compatibilization and improve interfacial adhesion. Functionalized PP is conventionally synthesized by melt extrusion at elevated temperature (T) (≥∼180 °C) with a radical initiator and polar monomer, e.g., maleic anhydride. A drawback to high T functionalization is that β-scission, which leads to cleavage of C–C backbone bonds, is significant and results in major molecular weight (MW) reduction and property degradation. We present a novel method of functionalizing PP using Benzoyl Peroxide (BPO) alone by a process called solid-state shear pulverization (SSSP), resulting in ester functional groups (benzoates) grafted at high yield onto PP. Ester functionalized PP (PP-g-ES) is synthesized with limited MW reduction because SSSP is done at sufficiently low T to suppress β-scission. Characterization before and after grafting at 0.18 mol % (0.46 wt %) graft level indicates that functionalizat...

Howard I. Maibach - One of the best experts on this subject based on the ideXlab platform.

  • Evaluating clinical trial design: systematic review of randomized vehicle-controlled trials for determining efficacy of Benzoyl Peroxide topical therapy for acne
    Archives of Dermatological Research, 2015
    Co-Authors: Sonia A. Lamel, Raja K. Sivamani, Maral Rahvar, Howard I. Maibach
    Abstract:

    Determined efficacies of Benzoyl Peroxide may be affected by study design, implementation, and vehicle effects. We sought to elucidate areas that may allow improvement in determining accurate treatment efficacies by determining rates of active treatment and vehicle responders in randomized controlled trials assessing the efficacy of topical Benzoyl Peroxide to treat acne. We conducted a systematic review of randomized vehicle-controlled trials evaluating the efficacy of topical Benzoyl Peroxide for the treatment of acne. We compared response rates of vehicle treatment arms versus those in Benzoyl Peroxide arms. Twelve trials met inclusion criteria with 2818 patients receiving Benzoyl Peroxide monotherapy treatment and 2004 receiving vehicle treatment. The average percent reduction in total number of acne lesions was 44.3 (SD = 9.2) and 27.8 (SD = 21.0) for the active and vehicle treatment groups, respectively. The average reduction in non-inflammatory lesions was 41.5 % (SD = 9.4) in the active treatment group and 27.0 % (SD = 20.9) in the vehicle group. The average percent decrease in inflammatory lesions was 52.1 (SD = 10.4) in the Benzoyl Peroxide group and 34.7 (SD = 22.7) in the vehicle group. The average percentage of participants achieving success per designated study outcomes was 28.6 (SD = 17.3) and 15.2 (SD = 9.5) in the active treatment and vehicle groups, respectively. Patient responses in randomized controlled trials evaluating topical acne therapies may be affected by clinical trial design, implementation, the biologic effects of vehicles, and natural disease progression. “No treatment” groups may facilitate determination of accurate treatment efficacies.

  • topical dose justification Benzoyl Peroxide concentrations
    Journal of Dermatological Treatment, 2013
    Co-Authors: Andreas J Brandstetter, Howard I. Maibach
    Abstract:

    Abstract Background: Benzoyl Peroxide (BPO) is widely utilized in acne treatment as an alternative to antibiotics against which Propionibacterium acnes becomes more resistant. Objective: This overview examines BPO dose justification. Methods: PubMed, Embase® and Science Citation Index searches were conducted using the keywords “Benzoyl Peroxide” and “acne vulgaris”. Results: Limited experimental data are available. However, there appears no significant difference in the efficacy of concentrations from 2.5% to 10%. Discussion: The extent of free fatty acids and the percutaneous penetration of BPO may not play a critical role in acne vulgaris.

  • keratolytic properties of Benzoyl Peroxide and retinoic acid resemble salicylic acid in man
    Skin Pharmacology and Physiology, 2006
    Co-Authors: J. M. Waller, T Tiet, C Ford, Frank Dreher, Shabnam Behnam, Gerald D. Weinstein, Howard I. Maibach
    Abstract:

    Objectives: Retinoic acid (RA) and Benzoyl Peroxide (BP) were studied, comparing their keratolytic efficacy and water barrier disruption to that of salicylic acid (SA), a well-estab