POLYMERS & POLYMER COMPOSITES
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2022
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IF 1.841
Ming Gong,Daijun Zhang,Jiayang Zhang,Jun Li,Xiangbao Chen
Vinyl polymerization is an important path for in-situ polymerization of thermoplastic resins. BPO (Benzoyl peroxide) and DMT (dimethyl-p-toluidine) were chosen to initiate the radical polymerization of MMA (methyl methacrylate) in this work. Optimization of initiator concentration was studied through reaction rate of polymerization progress and properties of PMMA (polymethyl methacrylate). At first, the catalytic of DMT in MMA polymerization was studied through polymerization experiments and rheological experiments. Results showed that DMT could catalyze more than one molecular BPO in the whole reaction period. It can catalyze the decomposition of BPO after being connected to PMMA chains. Second, the BPO: DMT ratio was set to 2:1 to study the ideal content by comparing the mechanical properties of PMMA. Results showed that with the increase of initiator contents, Tg, molecular weight, and residual monomer were all declining. Meanwhile, the mechanical properties of PMMA matrix first increased and then decreased. This phenomenon was analyzed by 1H-NMR and SEM. And the optimal BPO-DMT concentration was 1.0 mol%–0.5 mol%.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2017
·Vol. 243
·期 12
·2265-2273
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IF 1.664
Wang Xiaobin,Huang Wenqian,Zhao Chunjiang,Wang Qingyan,Liu Chen,Yang Guiyan
Raman hyperspectral imaging technology not only can acquire the image information of the sample; it also contains the Raman spectra information about each pixel. Due to the abundant information that the method provides, it has been applied to detect food safety. This study adopted line-scan Raman hyperspectral technology to quantify benzoyl peroxide (BPO) additive in flour. By analyzing the Raman spectra of BPO and flour, the 999 cm −1 Raman peak was selected for the detection and identification of BPO in flour. Savitzky–Golay filter and adaptive iteratively reweighted penalized least squares (airPLS) methods were used to de-noise and fluorescence correction of the original Raman signals. Binary image was established by 999 cm −1 single-band correction image and threshold segmentation, and this method was used to detect 11 mixture samples with different BPO additive concentrations. The results show that the BPO additives in the mixture samples can be detected, and the detected BPO pixels had a good linear relationship with the concentration of BPO in the mixture samples, correlation coefficient was 0.9902. The above results indicated that the method established in this paper can be applied to non-destructive quantitative detection of BPO additive in flour.
研究领域:
食品科学
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分析化学
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光谱学
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DOI
高影响因子
MATERIALS RESEARCH INNOVATIONS
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2025
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IF 0
Yu Tian,Feiyao Huang,Di Zhu,Li Jiang,Qimin Jiang,Hongjun Yang,Wenyan Huang,Xiaoqiang Xue,Bibiao Jiang
The branched poly (2-hydroxyethyl methacrylate)(BPHEMA) was carried out using 2-methyl-n-[3-(methyl phenyl amino)-propyl]–acrylamide(MPAEMA, synthesised in laboratory) and benzoyl peroxide(BPO) as redox initiator by water/toluene inverse emulsion polymerisation. The weight-average molecular weight (Mw.MALLS), mean-square radius of gyration(Rg), intrinsic viscosity([η]), relative branching factor g and g’, and micro rheological properties of BPHEMA were measured by static and dynamic light scattering(DLS-SLS) and Ubbelohde viscometer. The results show that the BPHEMA was synthesised by inverse emulsion polymerisation at room temperature. The degree of branching increased with the increase of the content of reducing agent MPAEMA in the feed ratio, and the molecular weight was not affected significantly by the change of feed ratio. However, the molecular weight of linear poly (2-hydroxyethyl methacrylate) (LPHEMA) was significantly affected by the change of feed ratio.
研究领域:
高分子化学
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材料科学
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物理化学
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DOI
MICROCHEMICAL JOURNAL
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2025
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IF 5.1
Leijun Xu,Xiaoyan Geng,Jihong Deng,Zhenshuo Chen,Dengmin Li,Hui Xiao,Hui Jiang
The safety of wheat flour as a crucial food ingredient is paramount. Benzoyl peroxide (BPO) is banned in wheat flour in many regions due to health risks, yet it may be illegally added to enhance appearance. In the present study, BPO adulteration in wheat flour was quantitatively analyzed using terahertz time-domain spectroscopy (THz-TDS). First, the spectral characterization of wheat samples at 0.1–6 THz was obtained, and THz spectral data within specific frequency bands was processed using Savitzky-Golay (SG) filtering. Then, Competitive Adaptive Reweighted Sampling (CARS) and Variable Combination Population Analysis (VCPA) methods were used to select optimal frequency points. Finally, a chemometric model combining linear models (Lasso Regression, Ridge Regression, and Partial Least Squares Regression) with nonlinear models (Back-Propagation Neural Network, Random Forest, and Support Vector Machine) was employed for quantitative analysis. The experimental outcomes demonstrated that the detection models established through the standard analytical process met the detection requirements ( R P ≥ 0.95), and the best performance results were obtained from the chemometric models based on linear relationships. Among them, the Lasso Regression and Ridge Regression models obtained after optimization of the VCPA method had high prediction accuracy ( R P ≥ 0.97). The results showed that the THz spectroscopy technique combined with standard chemical analysis procedure could effectively realize the quantitative detection of BPO in wheat flour, providing an efficient and reliable tool for the safety detection of wheat flour.
研究领域:
食品安全
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光谱学
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分析化学
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化学计量学
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应用物理学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）