Benzoyl Peroxide Concentration Research Articles

Proliferation and differentiation of MC3T3-E1 cells on polymethyl methacrylate cements containing Fe3O4 and TiO2 for hyperthermic treatment of metastatic bone tumors.

Polymethyl methacrylate (PMMA) bone cement is widely used to relieve pain caused by metastatic bone tumors. We previously found that PMMA bone cement containing 15 mass% or more of TiO2 showed good apatite-forming ability, and 25 mass% or more of Fe3O4 generated sufficient heat for hyperthermia under an alternating current (AC) magnetic field. In this study, the cytocompatibility of PMMA bone cement with Fe3O4:TiO2 weight ratios of 25:15 (F25T15-3/2-42) and 30:15 (F30T15-3/2-42) was evaluated using osteoblastic cells (MC3T3-E1). The proliferation and differentiation of MC3T3-E1 cells were suppressed for F25T15-3/2-42 and F30T15-3/2-42 compared to PMMA bone cement without Fe3O4 and TiO2 (F0T0-3/2-42). The release of methyl methacrylate (MMA) monomers from F25T15-3/2-42 and F30T15-3/2-42 at 7days was about 33 and 50times higher than that from F0T0-3/2-42, respectively. The remarkable release of MMA monomers from F25T15-3/2-42 and F30T15-3/2-42 may be responsible for the suppressed proliferation and differentiation of MC3T3-E1 cells. The release of MMA monomers was not reduced when the MMA/PMMA weight ratio was decreased from 3/2 to 1/1, however, it was significantly reduced by increasing the content of benzoyl peroxide (BPO) and N, N-dimethyl-p-toluidine (DMPT) to 8 and 4 mass% against MMA, respectively. Proliferation and differentiation of MC3T3-E1 cells on PMMA-type cements containing Fe3O4 and TiO2 with increased BPO and DMPT contents need to be investigated in the future; however, our findings will be useful for designing PMMA cements for the hyperthermic treatment of metastatic bone tumors.

Enhancing interfacial interaction of immiscible PCL/PLA blends by in-situ crosslinking to improve the foamability

The immiscible between poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) significantly hinders the properties and application of the blends. In this work, the use of benzoyl peroxide (BPO) is an effective methods to improve the compatibility and foamability of immiscible PCL/PLA blends. The tensile test results showed a 41% increase in yield tensile strength and a 632% increase in elongation at break of the crosslinked PCL/PLA/0.6%BPO film compared to the pristine PCL/PLA blends, which demonstrate the enhancement of PCL/PLA interfacial interaction. The melt strength of the blends was gradually increased due to the improvement of interfacial interaction, which led to the decrease of average cell size and the increase of cell density of the PCL/PLA foam. Moreover, the open-cell structure was altered to a highly close-cell structure with increasing BPO content. Consequently, structural-tunable foams can be obtained by varying degrees of interfacial interaction.

Influence of Benzoyl Peroxide and Divinylbenzene Concentrations on the Properties of Poly(glycidyl methacrylate‐co‐divinylbenzene) Magnetic Microspheres

AbstractIn this work, the synthesis of magnetic microspheres of poly(glycidyl methacrylate‐co‐divinylbenzene) via suspension polymerization is reported. The concentrations of divinylbenzeneand benzoyl peroxide in the microspheres synthesis are studied. The microspheres, characterized by thermal analysis , scanning electron microscopy, vibrating sample magnetometry , and light scattering detection , show good morphological control and thermal stability. This material presents a narrow size range and an appreciable fraction of superparamagnetic particles. The increase in divinylbenzene concentration can cause a decrease in the mean diameter of the microspheres. On the other hand, the increase in benzoyl peroxide concentration causes an increase in the mean diameter of the microspheres.

Influence of Initiator Concentration on the Polymerization Course of Methacrylate Bone Cement.

Background: The amount of oxidant (initiator) and reductant (co-initiator) and their ratio have a significant effect on the properties of polymethacrylate bone cement, such as maximum temperature (Tmax), setting time (tset) and compressive strength (σ). The increase in the initiating system concentration causes an increase in the number of generated radicals and a faster polymerization rate, which shortens the setting time. The influence of the redox-initiating composition on the course of polymerization (rate of polymerization and degree of double bond conversion) and the mechanical properties of bone cement will be analyzed. Methods: Bone cements were synthesized by mixing a powder phase composed of two commercially available methacrylate copolymers (Evonic) and a liquid phase containing 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), and triethylene glycol dimethacrylate (D3). As an initiating system, the benzoyl peroxide (BPO) as an oxidant (initiator) in combination with a reducing agent (co-initiator), N,N-dimethylaniline (DMA), was used. Samples were prepared with various amounts of peroxide BPO (0.05%, 0.1%, 0.2%, 0.3%, 0.5% and 0.7% by weight) with a constant amount of reducing agent DMA (0.5 wt.%), and various amounts of DMA (0.25%, 0.35% and 0.5% by weight) with a constant amount of BPO (0.3 wt.%). The polymerization kinetics were studied by differential scanning calorimetry (DSC). Doughing time and compressive strength tests were carried out according to the requirements of the ISO 5833:2002 standard. Results: The increase in polymerization rate was due to the increase in the amount of BPO. In addition, the curing time was shortened, as well as the time needed to achieve the maximum polymerization rate. The final conversion of the double bonds in the studied compositions was in the range 74-100%, and the highest value of this parameter was obtained by the system with 0.3 wt.% of BPO. The doughing times for each BPO concentration were in the range of 90-140 s. The best mechanical properties were obtained for the cement following the initiating system concentrations: 0.3 wt.% of BPO and 0.5 wt.% of DMA. Nevertheless, all tested cements met the requirements of the ISO 5833:2002 standard. Conclusions: Based on the conducted polymerization kinetic studies, the best reaction conditions are provided by an initiating system containing 0.3 wt.% of BPO oxidant (initiator) and 0.5 wt.% of DMA reductant (co-initiator). A decrease in the DMA amount caused a decrease in the polymerization rate and the amount of heat released during the reaction. The change in BPO and DMA concentrations in the composition had little effect on the doughing time of the studied bone cement. The cements showed similar doughing times, ranging from 90-225 s, which is comparable to the bone cement available on the market.

Colorimetric Sensor for Measuring Bleaching Benzoyl Peroxide (BPO) Content in Wheat Flour Based on Perovskite CsPbBr3 Nanocrystal: A Preliminary Study

Benzoyl peroxide (BPO) is one of the bleaching agents for flour that is widely used in food products, such as bread and noodles, which if consumed continuously can cause health problems. An excess of BPO in the body will cause vertigo, vomiting, neurasthenia, and a variety of diseases, resulting in serious damage to the liver and other organs. In this work, a colorimetric sensor using CsPbBr3 nanocrystal (NC) was studied to measure the BPO concentration in the solution. The halogen ion exchange reaction between CsPbBr3 NCs and iodine (I−) was carried out by adding oleylammonium iodide (OLAM-I) to the CsPbBr3 NC solution. The results show that the originally green emission of CsPbBr3 NC (515 nm) is turned into red-pink (660 nm) after addition with OLAM-I due to iodide ions exchange with bromide ions in CsPbBr3 NCs. The wavelength shift was occurred rapidly, only in 1 minute. The emission of CsPbBr3+OLAM-I (660 nm) solution was blue-shifted rapidly within 1-2 minutes after BPO addition. The magnitude of the emission wavelength shift proportional to the concentration of BPO concentration, with a higher concentration leads a higher wavelength shift (Δλ). Therefore, this wavelength shift can be used as rapid and real-time sensor for detecting BPO content in the real samples of white flour and noodles.

Development of periodic colored bands via frontal polymerization

The development of periodic brown-white colored structural patterns during the frontal polymerization process has been studied in Methacrylic acid (MAA), Resorcinol, Benzoyl peroxide (BP), and N, N Dimethyl aniline (DMA) reaction system. The reaction has been carried out in a thin glass test tube under ambient conditions. Pattern formation and their dependency on the concentration of MAA monomer, Resorcinol, and DMA initiator have largely been observed. Methanol has also been used as a solvent to optimize the effect of dilution levels on the periodicity of colored structural patterns. The materials characterization is carried out using NMR, SEM, IR, CHNS, and UV–visible analyses to show the possible reaction mechanisms and elemental composition of the polymerization reaction. It has been observed that white and brown colored polymeric phases are formed during FP reactions and polymerized simultaneously. In this context, a possible chemical mechanism has been proposed which shows the formation of white colored polymethacrylic acid and brown phase poly (2–hydroxy, 1, 4 napthaquinone methacrylic acid). The analytical data observed during the study has a good agreement with the proposed chemical mechanism. The characteristics of colored patterns found depending on the concentration of resorcinol, BP, and EtOH have been studied and properly discussed.

Poly(poly(ethylene glycol) methyl ether acrylate) micelles for highly CO2 permeable membranes

Herein, we report highly CO2-permeable membranes obtained by blending in situ self-assembled micellar-structured poly(poly(ethylene glycol) methyl ether acrylate) (PPEGMEA) with poly(ether-block-amide) (Pebax). PPEGMEA with different molecular weights were prepared by varying the concentration of benzoyl peroxide (BPO) in a Pebax/PEGMEA/BPO mixture during radical polymerization. Significantly, the Pebax/PPEGMEA (30/70 w/w) blend membrane comprised highly CO2-philic PPEGMEA micelles, which appreciably increased the d-spacing of the Pebax matrix. Consequently, the blend membrane containing a high molecular weight of PPEGMEA exhibited an unprecedented CO2 permeability enhancement of 1054% compared to the pristine Pebax membrane while maintaining good CO2 selectivity relative to H2, O2, N2, CO, and CH4 because of the enriched polyethylene glycol moieties. This excellent separation performance was maintained for 100 h, validating the good long-term separation performance of the membrane. Furthermore, the membrane exhibited good mechanical strength and plasticization tolerance, resulting in excellent CO2 separation performance under equimolar CO2/N2 or CO2/CH4 mixed gas conditions (CO2 permeability of 1250 Barrer and CO2/N2 and CO2/CH4 selectivity of 31.5 and 12.7, respectively), up to a CO2 partial pressure of 10 atm. Our simple but effective in situ micelle-induced blending approach is a significant step toward realizing high-performance CO2 separation membranes.

Grafting of Poly(ethylene imine) to Silica Nanoparticles for Odor Removal from Recycled Materials.

One of the major obstacles to the reuse of recycled plastic materials is the emanation of after-process odors from recycled polymers and composites. Typically, recycled polymers are blended with an off-odor adsorbent additive in the recycling chain to eliminate these smells. This article describes an innovative ultrasonically assisted method of grafting poly(ethylene imine) (PEI) to silica nanoparticles (SiO2) initiated by benzoyl peroxide (BP) which acts as an odor remover. To prepare the PEI/Si, the branched PEI was grafted onto the silica surface without a coupling agent. This made the grafting process straightforward, easy and low in cost. Fourier Transform Infrared (FTIR) analysis confirmed the successful grafting of PEI to silica. The thermogravimetric analysis (TGA) indicated the formation of two different fractions: a polymeric fraction covalently attached to the nanoparticle surface and a non-grafted PEI fraction that was removed during extraction. Up to 30% of the grafted-PEI fractions were produced at the lowest BP concentration with the highest PEI molecular weight at silica-to-PEI weight ratios of (1:1) to (3:1). The sensory assessment showed a substantial reduction in overall odor intensity for 30% of the recycled plastic-containing materials and a ~75% reduction in volatile organic compounds (VOCs) for 100% of the recycled plastics. These results strongly suggest that this innovative PEI/Si nanocomposite can be successfully commercialized for odor removal. To the authors’ best knowledge, this is the first reported work describing a one-pot reaction for grafting PEI to different nanoparticle surfaces.

Graft polymerization of methyl methacrylate on the surface of poly(ethylene‐co‐tetrafluoroethylene) using benzoyl peroxide as initiator

AbstractThe surface of a poly(ethylene‐co‐tetrafluoroethylene) (ETFE) film was modified by benzoyl peroxide (BPO)‐initiated graft polymerization of methyl methacrylate (MMA). After graft polymerization, the appearance of the ETFE film changed considerably, and the Fourier transform infrared (FT‐IR) spectra showed absorption peaks attributed to carbonyl functionalities. The efficiency of graft polymerization was strongly influenced by several factors such as the reaction temperature, reaction time, and concentration of BPO. The highest graft yield (69%) was obtained at 0.1 mol% BPO concentration and at a reaction temperature of 75°C for 24 h. The properties of the ETFE film surface were altered by the graft polymerization of MMA, which facilitated dyeing of the surface.

Minimum Contact Time of 1.25%, 2.5%, 5%, and 10% Benzoyl Peroxide for a Bactericidal Effect Against Cutibacterium acnes.

PurposeBenzoyl peroxide (BPO) is an effective acne treatment and has been used as a cleanser and short contact therapy. However, data on the minimum contact time of BPO needed to kill Cutibacterium acnes are lacking. Thus, the aim of this study was to determine the minimum contact time of commonly used BPO concentrations for bactericidal effects on C. acnes.Materials and MethodsAn in vitro experimental study of clinically isolated C. acnes was performed to determine the minimal inhibitory concentration (MIC) of BPO using the broth microdilution method. Subsequently, the minimum contact times of various concentrations of BPO were evaluated, and their bactericidal effects were assessed by the plate count method.ResultsThe median MIC of BPO was 9375 µg/mL, which did not significantly differ between antibiotic-resistant and nonresistant C. acnes. The minimum contact time of BPO with C. acnes was significantly different among the BPO concentrations. For bactericidal activity against all isolates, 1.25%, 2.5%, 5%, and 10% BPO required 60 min, 15 min, 30 sec, and 30 sec, respectively.ConclusionBPO demonstrated bactericidal activity against both antibiotic-resistant and antibiotic-susceptible C. acnes. The in vitro contact time needed to kill C. acnes was almost immediate with 5% or more BPO, but ≤ 2.5% BPO required longer contact times for bactericidal effects.

Colorimetric Sensing of Benzoyl Peroxide Based on the Emission Wavelength-Shift of CsPbBr3 Perovskite Nanocrystals

Using the ionic salt characteristics of CsPbBr3 perovskite nanocrystals (CsPbBr3 NCs), the fluorescence wavelength of CsPbBr3−xIx NCs could be changed by the halogen exchange reaction between CsPbBr3 NCs and oleylammonium iodide (OLAM-I). Under the excitation of a 365 nm UV lamp and the increase of OLAM-I concentration, the content of iodine in CsPbBr3−xIx NCs increased, and the fluorescence emission wavelength showed a redshift from 511.6 nm to 593.4 nm, resulting in the fluorescence color change of CsPbBr3 NCs from green to orange-red. Since OLAM-I is a mild reducing agent and easily oxidized by benzoyl peroxide (BPO), a novel colorimetric sensing approach for BPO based on the fluorescence wavelength shift was established in this study. The linear relationship between the different wavelength shifts (Δλ) and the concentration of BPO (CBPO) is found to be in the range of 0 to 120 μmol L−1. The coefficient of alteration (R2) and the detection limit are 0.9933 and 0.13 μmol L−1 BPO, respectively. With this approach, the determination procedure of BPO in flour and noodle samples can be achieved in only a few minutes and exhibit high sensitivity and selectivity.

Study on the Penetration Depth of Light into Wheat Flour by Hyperspectral Imaging

The penetration depth of light into wheat flour is the basis for the effective detection of additives in wheat flour using hyperspectral imaging. To determine the effective penetration depth of light into different gluten flours in hyperspectral image collection, the partial least squares-discriminant analysis (PLS-DA) method was used. Double-layer samples were prepared by placing flour layers with different thicknesses on top of the benzoyl peroxide (BPO) layer. PLS-DA classification model was established by using the diffuse reflectance spectra of each pixel in the double-layer sample image, and the classification accuracy was used to evaluate the results. The results show that the average accuracy of 1 and 1.5 mm models after smoothing pretreatment is above 95%. Therefore, a 1.5 mm sample depth for the detection of mixed samples of flour and additives is recommended. The selected sample depth was used for the detection of mixed samples containing different concentrations of BPO in flour, and the percentage of detected BPO pixels was positively correlated with BPO concentration, which could be used for subsequent quantitative analysis. The results lay a foundation for the effective detection additives in wheat flour by using hyperspectral imaging technology.

Physicochemical WPC Modification Techniques

The paper studies issues related to physicochemical and chemical techniques for the modification of wood-polymer composites with a thermoplastic polymer matrix (WPCs) to improve their physical and mechanical properties. The physicochemical modification was performed by photochemical crosslinking with the exposure of WPC specimens to UV irradiation. Chemical modification was performed by introducing benzoyl peroxide into the material composition, leading to chemical crosslinking of polyethylene macromolecules of the WPC polymer matrix. As a result of the study, quantitative characteristics of the effect of the benzoyl peroxide content in the composite, as well as the WPC specimen UV irradiation intensity and duration on the basic physical and mechanical properties of the material have been obtained. The efficiency of physicochemical techniques for modifying WPCs has been estimated by changing the specimen properties such as Brinell hardness, water absorption, and impact strength. It has been found that the Brinell hardness increases by 80 % as compared to unmodified WPC specimens. Effective modification of wood-polymer composites with polymer matrices based on high-density polyethylene may lead to a significant improvement in the quality of products made of these materials.

Surface Modification of Areca Fibre by Benzoyl Peroxide and Mechanical Behaviour of Areca-Epoxy Composites

Natural fibre composites are playing great role in current life scenario where the focus is more on replacing synthetic fibre composites with natural fibre composites. In this current study, investigation was done on tensile and flexural behaviour of benzoyl peroxide treated areca sheath fibre epoxy composites. The surface modification of the fibre was confirmed by FTIR analysis. Treatment concentration was the major criteria which effects mechanical properties of the composites. At 4% concentration tensile strength and flexural strength was found to be maximum which was reported as 37.05 N/mm2 and 235.5 N/mm2 respectively which gradually decreased with increasing concentration of benzoyl peroxide. SEM analysis proved that at lesser concentration, the bonding between fibre and resin was effective which reduced as the concentration of benzoyl peroxide increased. This results in ineffective stress transfer between reinforcing material and the matrix which was the reason for failure of composites manufactured at higher treatment concentration.

Reactive Extrusion of Maleic-Anhydride-Grafted Polypropylene by Torque Rheometer and Its Application as Compatibilizer.

This study is based upon the functionalization of polypropylene (PP) by radical polymerization to optimize its properties by influencing its molecular weight. Grafting of PP was done at different concentrations of maleic anhydride (MAH) and benzoyl peroxide (BPO). The effect on viscosity during and after the reaction was studied by torque rheometer and melt flow index. Results showed that a higher concentration of BPO led to excessive side-chain reactions. At a high percentage of grafting, lower molecular weight product was produced, which was analyzed by viscosity change during and after the reaction. Percentage crystallinity increased by grafting due to the shorter chains, which consequently led to an improvement in the chain’s packing. Prepared Maleic anhydride grafted polypropylene (MAH-g-PP) enhanced interactions in PP-PET blends caused a partially homogeneous blend with less voids.

Is benzoyl peroxide detectable under physiological conditions in orthopaedic cement?

Background: Until today, benzoyl peroxide (BPO) as a potential polymethyl methacrylate (PMMA) cement allergen is the subject of controversial discussion. Question/Purposes: Few cases have been reported in literature and ought to be seen critically. To address this issue, the present study aims to determine BPO and their degradation products biphenyl (BP) and benzoic acid (BA) within hardened cement as well as their elution from cement. Methods: Six ordinary cements characterised by different BPO: DmpT ratio were chosen for the study. Subsequently, cements were tested in-vitro under destructive, physiologic and non- physiologic conditions. Results: BPO was not detectable under destructive and physiological conditions. Cements with a N, N-Dimethyl-para-toluidine (DmpT) surplus contained lower BPO, BP and BA concentrations compared to cements with BPO surplus. Conclusions: Furthermore, the ratio of DmpT:BPO had an impact on the turnover of BPO and its degradation products. Clinical Relevance: Moreover, BPO and BP elution under physiological conditions was not detectable (<0.1 μg/mL in saline solution at a ratio of 1+9 cement to saline solution), calling into question whether BPO is relevant as PMMA cement allergen.

Evaluation of multiple reactions in dilute benzoyl peroxide concentrations with additives using calorimetric technology

Benzoyl peroxide (BPO) is a typical organic peroxide widely used in food processing, particularly flour bleaching. Due to the unstable nature of the oxygen-oxygen bond in BPO, it readily reacts under even mid-low-temperature conditions. Lower concentrations of BPO are also potentially explosive, even when combined with acid or alkaline additives. Given the history of both potential and documented industrial accidents, this study investigates the thermal stability of various BPO concentrations when mixed with acid or alkaline solutions. In addition, differential and integral kinetic models were applied to verify that the apparent activation energy data from the differential scanning calorimetry experiments were valid. The results of autocatalysis reactions and nth-order reaction simulations presented characteristics consistent with the experimental findings. The findings in this paper can be used as a reference for BPO products that are mediated with either an acid or an alkaline solution during production, storage, transportation, or use.

What are the benefits and harms of using higher versus lower concentrations of topical benzoyl peroxide for people with acne?

What are the benefits and harms of using higher versus lower concentrations of topical benzoyl peroxide for people with acne?

Development of dual-cured resin cements with long working time, high conversion in absence of light and reduced polymerization stress

ObjectiveThis study evaluated the properties of experimental dual-cured cements containing thiourethane (TU) and low concentrations of p-Tolyldiethanolamnie (DHEPT) and benzoyl peroxide (BPO) as chemical initiators. MethodsBisGMA/TEGDMA-based dual-cured cement was formulated with 1.0 wt% DHEPT and 0.75 wt% BPO as initiators and used as control. The concentration of BPO was adjusted to 0.1 wt% in catalyst paste of experimental cements, and two base pastes containing TU and 0.5 wt% or 0.25 wt% of DHEPT were formulated. The rheological behavior and kinetics of polymerization of cements were assessed in the absence of light activation. The kinetics of polymerization was also evaluated for cements light-activated immediately or 5 min after the start of mixing. Polymerization stress, flexural strength and elastic modulus (n = 5) were also evaluated under these conditions. ResultsCements with TU presented lower viscosity than the control, improved working time (0.25% DHEPT > 0.5% DHEPT) and higher conversion in the absence of light-activation. Delaying the light-activation reduced the maximum rate of polymerization (Rpmax) but did not affect the conversion or stress. The addition of TU increased the Rpmax and conversion, and reduced the stress when compared to the control, without affecting the flexural strength. Except for the control with delayed light-activation (highest values), the other experimental conditions yielded similar modulus. SignificanceAdding TU and using a low concentration of DHEPT/BPO resulted in dual-cured cements with longer working time, reduced polymerization stress and increased conversion even in the absence of light, with no significant effect on the mechanical properties.

Superabsorbent polymer composites derived from polyacrylic acid: Design and synthesis, characterization, and swelling capacities

Superabsorbent polymers (SAPs) were synthesized by aqueous solution polymerization of carboxymethyl cellulose (CMC)/acrylic acid (AAc) and polyvinyl alcohol (PVA)/AAc blend using benzoyl peroxide as an initiator. SAPs were synthesized by a facile method under mild conditions. A comparative study was done between CMC/AAc as a biodegradable superabsorbent and PVA/AAc copolymer. The effects of cross-linking, reaction time, temperature, and initiator molar ratio on water absorbency were studied herein. The highest swelling capacity was obtained for CMC/AAc biodegradable superabsorbent composite. The water absorption capacity of SAPs increased with increases in benzoyl peroxide content, immersion time, and reaction temperature of polymerization. The gel fraction of SAPs decreased with increases in the amounts of N, N′-methylenebisacrylamide as a cross-linker. Fourier-transform infrared spectroscopy was used to examine the molecular interactions. The morphology and structure of superabsorbent composites were investigated by scanning electron microscopy.