INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
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IF 4.326
Bo Wang,Senlin Deng,Yuhang Bian,Guoliang Zhang,Chunshan Li
The aldol condensation of methyl propionate (MP) and formaldehyde (FA) is an environmentally friendly and sustainable route to produce methyl methacrylate (MMA). However, the side reaction is a huge barrier to achieving high selectivity to the target product. To strengthen the regulation of selectivity for the main reaction, a reaction network was established based on the validation and analysis of side reactions in the system through a combination of experimental and computational methods. The thermodynamics was analyzed through the Gibbs free energy (ΔrGTθ) of reactions. On the basis of a rigorous material balance of all components, the sources and reaction equations of 15 products were identified. The multivariate nonlinear model between the yield of different products and reaction conditions was established to predict the yield of each product. The mean relative error of the actual yield and predicted yield was less than 5%. The key influencing condition for the synthesis of MMA was the liquid hourly space velocity (LHSV).
研究领域:
化学工程
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环境科学
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DOI
高影响因子
CHEMICAL PAPERS
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2023
·Vol. 77
·期 7
·3713-3726
·
IF 2.2
Xue Tao,Wei Yan,Yu Caili,Zhou Zhongqun,Zhang Faai
A series of mesoporous silica (MS) materials, including rod-like and spherical SBA-15, spherical MCM-41, and MCM-48, was successfully synthesized and modified by silane coupling agent γ-aminopropyltriethoxysilane. The modified MS was utilized as a microreactor for solution reversible addition–fragmentation transfer (RAFT) polymerization of methyl methacrylate (MMA) using xanthate as a chain transfer agent and azodiisobutyronitrile as an initiator. Notably, modified MS had a low specific surface area and pore volume while maintaining the original morphological structure. Given to the confinement effects, poly(methyl methacrylate) (PMMA) prepared from internal mesoporous channels had higher molecular weight and initial thermal decomposition temperature than those from conventional RAFT polymerization. Moreover, PMMA obtained from spherical SBA-15 and modified MCM-48 exhibited the highest molecular weight ( M n = 8.78 × 10 4 and M n = 7.43 × 10 4 , respectively). This work provided a novel approach in designing a polymer microstructure for a more comprehensive application, such as in drug release. Graphical abstract
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
POLYMER SCIENCE SERIES B
·
2023
·Vol. 65
·期 4
·409-418
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IF 1.2
Shoucun Zhang,Wang Shengyan,Bian Yujing,Fang Guoli
Abstract Carbon dioxide is a well-known green solvent, and can be used instead of some organic solvent to prepare the polymer products. On the basis of its poor solubility, dispersion polymerization can be adopted to produce the polymer products in industry. Thus, low price, easily available stabilizers with good stabilization effect will be a must. In this paper, we are committed to designing and synthesizing stabilizers with these characteristics. Firstly, thiol ethanol is used as the chain-transfer agent to control the copolymerization of vinyl acetate/vinyl propionate, and the homopolymers or copolymers with the hydroxyl group at the chain terminal are obtained. These homopolymers or copolymers are then functionalized to prepare the stabilizers with methacrylate groups. The results indicate that these stabilizers can effectively control the dispersion polymerization of methyl methacrylate in supercritical carbon dioxide. The proportion of structural units in the copolymer and the concentration of stabilizer or initiator obviously affect the conversion percentage of methyl methacrylate and the molecular weight of polymers. The maximum conversion percentage of methyl methacrylate and the molecular weight of poly(methyl methacrylate) can reach 93%, and 56000 Da, respectively. SEM images show that most of the samples are free-flowing powders with a spherical structure.
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
JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 32
·
IF 1.768
Li-chao Liu,Mang Lu,Zhao-Hui Hou,Guo-Xiang Wang,Chang-An Yang,En-Xiang Liang,Hu Wu,Xian-Lei Li,Yi-Xue Xu
Photo-induced atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved in poly(ethylene glycol)-400 with nanosized α-Fe 2 O 3 as photoinitiator. Well-defined poly(methyl methacrylate) (PMMA) was synthesized in conjunction with ethyl 2-bromoisobutyrate (EBiB) as ATRP initiator and FeCl 3 ·6H 2 O/Triphenylphosphine (PPh 3 ) as complex catalyst. The photo-induced polymerization of MMA proceeded in a controlled/living fashion. The polymerization followed first-order kinetics. The obtained PMMA had moderately controlled number-average molecular weights in accordance with the theoretical number-average molecular weights, as well as narrow molecular weight distributions ( M w / M n ). In addition, the polymerization could be well controlled by periodic light-on–off processes. The resulting PMMA was characterized by 1 H nuclear magnetic resonance and gel permeation chromatography. The brominated PMMA was used further as macroinitiator in the chain-extension with MMA to verify the living nature of photo-induced ATRP of MMA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42389.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2013
·Vol. 20
·期 7
·1-11
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IF 2.019
Cheng Chuanjie,Bai Xiongxiong,Liu Shaojin,Huang Qinghua,Tu Yuanming,Wu Haiming,Wang Xiaoji
A cardanol-derived reversible addition-fragmentation chain transfer (RAFT) agent was synthesized in 57 % total yield, and a cardanol-based anionic surfactant was also facilely prepared. Emulsion polymerization of methyl methacrylate (MMA) was realized to form a cardanol-terminated PMMA polymer by using the novel RAFT agent as well as the cardanol-based anionic surfactant. To improve the properties of cardanol-terminated PMMA as a material, UV-curing was performed. According to the comprehensive behavior of the UV-cured resins, optimal irradiation time was 20 min.
研究领域:
材料科学
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高分子化学
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可持续化学
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DOI
高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
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2023
·
IF 5
Siyuan Yu,Jinfeng Xing
Erythromycin (EM) was encapsulated into poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate- co - N -vinylcaprolactam) (P(MMA-NVCL)) microspheres in situ by oil-in-water emulsion photopolymerization under green LED irradiation. The physicochemical properties of PMMA-EM and P(MMA-NVCL)-EM microspheres were characterized by SEM, FTIR, TG-DSC and DLS. P(MMA-NVCL)-EM microspheres showed temperature sensitivity, and the EM loading content of PMMA-EM and P(MMA-NVCL)-EM microspheres reached 9.7% and 15.6%, respectively. In vitro release of EM from microspheres presented good controlled release behavior in 12 h. Further release kinetic and thermodynamic investigation revealed that the release process was mainly dominated by EM concentration, accompanied by microspheres relaxation and rupture of hydrogen bonds .
研究领域:
材料科学
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药学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
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2021
·
IF 3.115
Jihe Zhao,Xuefeng Gui,Wenhai Zhang,Shudong Lin,Yuanyuan Tu,Jiwen Hu,Daguang He,Xiaohua Huang
Thermal runaway primarily occurs during the course of copolymerization due to the release of large amounts of heat. In this paper, the thermal risk associated with styrene-methyl methacrylate bulk copolymerization was firstly investigated by differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). The result found that the exothermic behavior was greatly affected by the initiator concentration, in contrast the exothermic enthalpy was not. This exothermic behavior was firstly illustrated via polymerization mechanism. The temperature and pressure have changed dramatically during the adiabatic runaway copolymerization, which demonstrated a great potential risk of thermal runaway. Kinetic parameters, such as T NR , T SADT was calculated accordingly, which provided guidance for the safety of storage and transportation. This study will provide a helpful safety assessment for the styrene-methyl methacrylate bulk copolymerization, which is widely used in industry.
研究领域:
化学工程
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材料科学
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安全科学
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产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 11
·2501
·
IF 5
Panpan Zhang,Qiongqiong Xu,Wenyu Mao,Jiaxing Lv,Haodong Tang,Huadong Tang
A novel synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) using organosulfur compounds combined with a catalytical amount of transition metal carboxylates as an initiator has been developed. The combination of 1-octanethiol with palladium trifluoroacetate (Pd(CF3COO)2) was found to be a very efficient initiator for the polymerization of methyl methacrylate (MMA). An ultrahigh molecular weight PMMA with a number-average molecular weight of 1.68 × 106Da and a weight-average molecular weight of 5.38 × 106Da has been synthesized at the optimal formulation of [MMA]:[Pd(CF3COO)2]:[1-octanethiol] = 94,300:8:23 at 70 °C. A kinetic study showed that the reaction orders with respect to Pd(CF3COO)2, 1-octanethiol, and MMA are 0.64, 1.26, and 1.46, respectively. A variety of techniques such as proton nuclear magnetic resonance spectroscopy (1H NMR), electrospray ionization mass spectroscopy (ESI-MS), size exclusion chromatography (SEC), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electron paramagnetic resonance spectroscopy (EPR) were employed to characterize the produced PMMA and palladium nanoparticles (Pd NPs). The results revealed that Pd(CF3COO)2was firstly reduced by the excess of 1-octanethiol to form Pd NPs at the early stage of the polymerization, followed by the adsorption of 1-octanethiol on the surface of nanoparticles and subsequent generation of corresponding thiyl radicals to initiate the polymerization of MMA.Keywords:ultrahigh molecular weight;PMMA;polymerization;kinetics;mechanism
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
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2018
·
IF 2.955
Guoxiong Dai,Qingyi Xie,Shanshan Chen,Chunfeng Ma,Guangzhao Zhang
Being biodegradable and eco-friendly, polyesters are promising in marine anti-biofouling. However, the slow degradation and poor adhesion limit their applications. In the present work, we have prepared poly(ester)-poly(methyl methacrylate) copolymer via radical ring-opening copolymerization of 2-methylene-1,3-dioxepane (MDO) and methyl methacrylate (MMA). The copolymer coating has good adhesion to substrate due to the incorporation of MMA moieties. The main-chain ester bonds from MDO enable the copolymer to enzymatically and hydrolytically degrade, and the degradation rate increases with the ester content. The polymers can serve as a carrier and controlled release matrix for organic antifoulant 4,5-dichloro-2-octylisothiazolone (DCOIT), and the release rate increases with the ester content. Marine field test shows the system of the copolymer and DCOIT has excellent antifouling performance for more than 3 months.
研究领域:
材料科学
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海洋生物学
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产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 63
·58218-58225
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IF 3.289
Henmei Ni,Junxiu Liu,Kai Shi,Min Wu,Yadong Yang,Lijuan Zhang
The reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of methyl methacrylate (MMA) was carried out in ethanol using polymethacrylic acid (PMAA)–4-cyanopentanoic acid dithiobenzoate (CADB) (degree of polymerization = 30, 122 and 450) as a macro chain transfer agent (CTA) and 2,2′-azobis(2,4-diemthyl valeronitrile) (V-65) as an initiator. In contrast to the random copolymerization systems, a dramatic increase of conductivity during the initial stage of RAFT polymerization was observed. It was confirmed that the conductivity resulted from the charged solvophobic blocks of soluble diblock copolymers, strongly dependent on the chain length of PMAA-CTA and PMMA. Objects of PMAA-b-PMMA were prepared by three methods, i.e. the polymerization-, temperature- and ion-induced self-assembly. The procedure of self-assembly commonly resulted in a dramatic decrease of conductivity. All results indicated that the electrostatic interaction played a role in the process of self-assembly, rather than just the solvophobic interaction of PMMA blocks in ethanol.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 10
·1285-1291
·
IF 1.536
Xie Chuanbao,Leng Kangwei,Sheng Jie,Wang Xuemei,Li Qianmin,Song Liang,Liu Lei,Sun Hejing,Huang Xiaowen,Wang Zhongwei,Yu Qing
Poly(methyl methacrylate) (PMMA) microspheres were synthesized through visible light–induced photopolymerization of methyl methacrylate (MMA). 2,4,6-Trimethylbenzoyldipenylphosphine oxide (TPO), polyvinylpyrrolidone (PVP), and light-emitting diodes (LEDs) were used as the photoinitiator, stabilizer, and light source, respectively. No other additive was involved. The effect of LEDs, TPO, and PVP was discussed. Results showed that PMMA microspheres with the size of 0.5–0.8 μm could be obtained when LED@385 nm was the light source, and the content of TPO and PVP was 2 wt% and 30 wt% of MMA. Moreover, the possible formation pathway of PMMA microspheres was proposed based on the investigation of reaction time and addition method of PVP.
Graphical abstract
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Processes
·
2019
·Vol. 7
·期 6
·377
·
IF 1.963
Taotao Liang,Xiaogang Guo,Abdulmoseen Segun Giwa,Jianwei Shi,Yujin Li,Yan Wei,Xiaojuan Wang,Xuansong Cao,Xiaofeng Tang,Jialun Du
Methyl methacrylate (MMA) plays a vital role in national productions with broad application. Herein, the production of MMA is realized by the improved eco-friendly direct methylation method using Aspen Plus software. Three novel kinds of energy-saving measures were proposed in this study, including the recycle streams of an aqueous solution, methacrolein (MAL), and methanol, the deployment of double-effect distillation instead of a normal one, and the design of a promising heat-exchange network. Moreover, MMA with a purity of 99.9% is obtained via the design of a MAL absorber column with an optimal stage number of 11 and a facile chloroform recovery process by using the RadFrac model. Thus, the proposed green process with energy-conservation superiority is the vital clue for developing MMA, and provides a reference for the production of MMA-ramifications with excellent prospects.Keywords:MMA;double-effect distillation;energy conservation;MAL;purity
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）