POLYMER BULLETIN
·
2019
·Vol. 77
·期 6
·3223-3235
·
IF 1.858
Jiang Jingzhe,Wei Anqi,Li Jianping,Ji Yue,Qiang Huijun,Jiang Yan,Zhang Hongwen,Liu Hongbo
In this paper, hydroxyl terminated polysiloxane was first prepared by ring-opening polymerization of octamethylcyclotetrasiloxane (D 4 ), which was then modified with acryloyl chloride to obtain acryloyloxy polysiloxane. A light-scattering material was synthesized by copolymerization of acryloyloxy polysiloxane and methyl methacrylate (MMA). The results showed that the transmittance of the material was 88% and the haze was 93% when the ratio of MMA to light-scattering agent was 100:1, the amount of initiator was 0.3%, and the post-polymerization temperature was 50 °C. The TGA data indicated that the material had excellent heat resistance. Therefore, it has a wide range of applications in the field of light-emitting diodes.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 11
·1217
·
IF 2.935
Jinku Xu,Dongmei Li
Transparent nanocomposite films containing quantum dots are popular because of their extensive applications. However, nanoparticles tend to aggregate, resulting in phase separation of the nanoparticles in the polymer matrix. Herein, we present a bulk thermo-curing copolymerization method to fabricate poly(methyl methacrylate)-based nanocomposite films with ultra-high-loading ZnS quantum dots (ZnS/PMMA), utilizing polymerizable group-capped ZnS and monomer of methyl methacrylate (MMA). We found that the nanocomposite film is highly transparent, although the transmittance decreases with the ZnS content, especially at the wavelength between 300 nm and 400 nm. The results from X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic mechanical thermal analysis (DMTA) show that the ZnS quantum dots maintain their original crystal structure, and are uniformly dispersed in the nanocomposite films, even with a very high ZnS content (41 wt %, determined by thermogravimetric analysis). The thermogravimetric analysis shows that the nanocomposite films possess a better thermal stability than that of pure PMMA film. The photoluminescence measurements show that ZnS/PMMA nanocomposite films have good optical properties. The fluorescence intensity increases with the increment of free ZnS content to 30 wt %, and then decreases due to self-reabsorption at a higher ZnS content. The transparent ZnS/PMMA nanocomposite films have a potential application as photoluminescence material.Keywords:nanocomposites;Quantum dots;poly(methyl methacrylate);photoluminescence
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Weilong Wu,Qin Ouyang,Liu He,Qing Huang
Polymethyl methacrylate (PMMA) is a widely used optical polymer due to its excellent transparency and durability. However, the sole methyl group shows pure PMMA low refractive index and low UV absorbility, and poor thermal stability. In this work, two comonomers phenyl methacrylate (PhMA) and adamantyl methacrylate (AdMA) were used for copolymerization with methyl methacrylate (MMA), and three copolymers P(AdMA-co-MMA), P(PhMA-co-MMA) and P(AdMA-co-PhMA-co-MMA) were prepared. They were characterised by FTIR , 1 H NMR, UV-Vis, ellipsometer , DSC , TG , and TG-MS, and the effects of phenyl and adamantyl substituents on the optical and thermal properties of PMMA were studied. It was found that phenyl played an important role in increasing the absorption and refraction of PMMA in the deep UV region (190–260 nm), while the glass transition temperature and thermal stability of PMMA were more affected by adamantyl than by phenyl. Introduction of phenyl and adamantyl substituents provided a method to tune the optical and thermal properties of PMMA as photoresist or antireflective coating for deep UV lithography.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2013
·
IF 1.913
Chao Shi,Yingchun Zhu,Huofei Qian,Liqiang Lu
The strong inorganic–organic composite was successfully fabricated by combination of the super stiff silicon nitride (Si 3 N 4 ) fibers and the leading flexible poly(methyl methacrylate) (PMMA) by initiating free radical polymerization in batch. Hydroxylation of Si 3 N 4 fibers made it feasible to modify the fibers with γ-methacryloxypropyltrimethoxysilane (γ-MPS), which was identified as linkage between Si 3 N 4 and PMMA through C C bond. The Si 3 N 4 –PMMA composite had a reduced modulus of 4.72 GPa, with the improvement of at least 52% to the matrix. The observation on morphology and structure of the composite demonstrated that the inorganic fibers were uniformly dispersed in the polymer matrix, and most importantly, they were well cross-linked by chemical bonds and van der Waals. The thermal stability of Si 3 N 4 –PMMA was raised with an increase in thermal decomposition and glass transition temperature. The composite with super mechanical properties and thermal stability may have potential applications in aerospace industry and civil engineering fields.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2016
·
IF 4.179
Hongling Zhou,Yangqiang Huang,Youwei Cheng,Lijun Wang,Xi Li
Hydrogenation of methyl methacrylate (MMA) was investigated over Ru-based catalyst supported on active carbons (AC), which was prepared by bio-reduction method, using C. Platycladi (CP) leaf extract as reductant. By varying reaction temperature, hydrogen pressure and reaction time, hydrogenation of MMA over the biosynthesis Ru-based catalyst was carried out, and resulted the optimum conditions, 30 °C (room temperature), 2.0 MPa, and 50 min. The as-prepared Ru/AC catalyst showed high catalytic activity towards the hydrogenation of MMA, affording 100% of MMA conversion even under mild conditions without solvent and methyl isobutyrate was the only product.
研究领域:
催化化学
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环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Jinyuan Bai,Yang Liu,Yanjun Hou,Shuhong Wang
A new luminescent europium(III) bis-β-diketonate complex, Eu 2 (PBT) 3 (NO 3 ) 3 (PBT = 1,1-(pyridine-2,6-diyl)bis(4,4,4-trifluoro-1,3-dione), was incorporated into the poly(methylmethacrylate) (PMMA) matrix and formed nanofibers via electrospinning technology. The different characterization techniques were adopted to reveal the effect of Eu 2 (PBT) 3 (NO 3 ) 3 on the spatial structure and optical properties of the nano-composite fibers obtained. The doping enhances the thermal stability and filament-forming properties for a series of PMMA-supported composite nanofibers Eu/PMMA, and in particular, the doping concentrations of 11 wt% also showed more efficient luminescence properties. Furthermore, the Judd-Ofelt theory was applied in this study to explain the effect of the distribution of Eu 2 (PBT) 3 (NO 3 ) 3 and the mutual effect of the Eu 2 (PBT) 3 (NO 3 ) 3 coordination compound and surrounding fractions of PMMA.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Chenxi Feng,Junyang Liu,Kai Zhao,Lei Wang,Zengxi Li,Guoliang Zhang,Chunshan Li
Methyl methacrylate (MMA) synthesis via aldol condensation of methyl propionate with formaldehyde over Cs-based supported catalysts is intensively investigated, while the effect of their pore structures on catalytic performance still lacks in-depth understanding. Herein, series of Cs-Zr/SiO 2 catalysts with different pore structures were prepared for this aldol condensation. The physicochemical characteristics of as-prepared Cs-Zr/SiO 2 catalysts were characterized using physical N 2 adsorption–desorption isotherms and CO 2 -/NH 3 -TPD. In addition, the impact of pore structure on mass transfer, adsorption, and desorption of reactants and products was studied through in situ DRIFTS. The results show that the acid and base site densities elevated with the increasing pore volume. The mass transfer of reactants and products could be promoted with increasing pore size, while their adsorption energies exhibited a volcanic trend. As a result, the Cs-Zr/SiO 2 catalysts having average pore diameter of 12-18 nm and acid-base balance was considered as the optimal candidate for MMA production.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 28
·
IF 1.768
Hang Xu,Haicun Yang,Liu Zhang,Qingting Ni,Fanghong Gong
The Core-shell hybrid particles with attapulgite (ATP) as the core and polymethylmethacrylate (PMMA) as the shell (ATP- g -PMMA) were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization method. The diameter of ATP- g -PMMA was increased to 50–60 nm, and the surface hygroscopicity was decreased observably after surface grafting. Then, ATP- g -PMMA hybrid particles were filled into the polycarbonate (PC) by melt mixing to afford nanocomposites, and the mechanical properties, microstructures, thermal stability, and rheological behavior of nanocomposites were investigated by varying ATP- g -PMMA concentration in the range 1, 3, 5, and 7 wt % in PC. Fourier Transform infrared spectroscopy (FTIR) suggested that there is no esterification reaction between particles and matrix. Slight changes in tensile strength, and noticeable decrease of elongation and impact strength were observed with the increase in ATP- g -PMMA particles loading. The morphology evaluated by field-emission scanning electron microscopy (FESEM) indicated that ATP- g -PMMA was dispersed with a diameter range of 80–100 nm, and phase separation was appeared with increasing ATP- g -PMMA loadings. Thermogravimetric analysis (TGA) results revealed the thermal stability of composites was strengthened. The disentanglement and interface slip induced by preferred orientation and directional arrangement of ATP- g -PMMA resulted in lower complex viscosity (η*) and higher loss factor (tan δ) compared with the pristine PC. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42262.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER ENGINEERING
·
2024
·Vol. 44
·期 9
·603-614
·
IF 1.7
Chengcheng Liu,Shibin Wang,Fei Jia,Bo Zheng,Shuaishuai Li,Yuheng Yang,Yang Gao,Jinzhou Zhao
A novel hydrophobic association copolymer (PAMA) was synthesized by incorporating acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), cationic monomer (MEDDA), and methyl methacrylate (MMA). The properties of MMA copolymers with varying contents were analyzed using infrared spectroscopy, nuclear magnetic resonance spectroscopy, and scanning electron microscopy. Optimal overall performance of the solution was achieved when the MMA content reached 1.4 % w/w. Compared to pure PAAM (without MMA), the PAMA-1.4 % polymer exhibited superior viscoelasticity, temperature resistance, and shear resistance. This enhancement in PAMA performance can be attributed to the significant inhibition of intermolecular water film formation within the polymer matrix by MMA, effectively improving and regulating solution solubility while strengthening molecular chain interactions and enhancing the structural network strength of PAMA polymers. Additionally, the inclusion of MMA transformed rock surfaces from non-wetting to wetting conditions, thereby greatly improving oil displacement efficiency. In displacement experiments, PAMA-1.4 % performed better in terms of enhanced oil recovery, the recovery rate of 0.1 % w/w PAMA-2.4 % solution is only 7.78 %, while the recovery rate of 0.1 % w/w PAMA-1.4 % solution is 13.06 %.
研究领域:
石油工程
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Zhenyu Wu,Zengxi Li,Chunshan Li
The bare amorphous Al 2 O 3 -AlPO 4 and Cs/Al 2 O 3 -AlPO 4 catalysts were developed for the aldol condensation of methyl acetate with formaldehyde to methyl acrylate. The structure and property of catalyst were characterized by XRD, XPS, BET, Pyridine-IR, FT-IR, 27 Al-MASNMR, NH 3 -/CO 2 -TPD and SEM. The correlation between structural features and acid-base properties was established, and the loading effect of the cesium species was investigated. Due to cooperative catalytic effects between the penta-coordinated Al and Al 2 O 3 , the weak-II acid and medium acid site densities and the product selectivity were improved. While the basic site densities of these catalysts were almost in proportion to the conversion of methyl acetate. The loaded Cs could form new basic sites and change the distribution of acid sites which further enhance the catalytic performance. As a result, the 10Cs/8AlP was proved to be an optimal catalyst with the yield and selectivity of 21.2% and 85% for methyl acrylate respectively. During the reaction, a deactivation behavior was observed on 10Cs/8AlP catalyst due to the carbon deposition, however, it could be regenerated by thermal treatment in the air atmosphere at 400 °C.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Composites and Advanced Materials
·
2021
·
IF 0
Li Jian
The surface treatment of carbon fibers (CFs) was carried out using a self-synthesized sizing agent. The effects of sizing agent on the surface of CFs and the interface properties of CF/polymethyl methacrylate (PMMA) composites were mainly studied. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and static contact angle were used to compare and study the CFs before and after the surface treatment, including surface morphology, surface chemical element composition, and wettability of the surface. The influence of sizing agent on the mechanical properties of CF/PMMA resin composite interface was investigated. The results show that after sizing treatment, the CF surface O/C value increased by 35.1% and the contact angles of CF and resin decreased by 16.2%. The interfacial shear strength and interlayer shear strength increased by 12.6%.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Yufei Tang,Lei Chen,Zihao Duan,Kang Zhao,Zixiang Wu
The introduction of BaTiO 3 (BT) particles into biomaterials, such as polymethyl methacrylate (PMMA) bone cement , is among the effective ways to improve their osteoinductivity. However, excessive addition leads to mechanical degradation . An important problem to solve is the manner by which piezoelectric properties matching human bones can be obtained under the premise of sufficient mechanical properties . The piezoelectric effect is obtained by adding BT particles into PMMA bone cement. The piezoelectric coefficient close to the human bone is obtained at a relatively low BT addition amount by adding graphene on this basis. High mechanical properties can also be obtained. Graphene increases the piezoelectric coefficient by increasing the conductivity, dielectric constant, and effective polarization voltage of graphene (G)/BT(BaTiO 3 )/PMMA bio-piezoelectric composites. The compression strength of the aforementioned composites increases from 83.5 MPa to 89.5 MPa after the addition of 0.5 vol% graphene, and the requirements of bone implant materials were met. G/BT/PMMA bio-piezoelectric composites have no cytotoxicity, and graphene can also promote cell adhesion and proliferation on the composite's surface. The polarized bio-piezoelectric composites can improve cell morphology and promote cell proliferation . The number of cells increases with increasing piezoelectric coefficient. The composite has potential application prospects in various fields, such as oral cavity and bone implant.
研究领域:
生物医学工程
·
材料科学
✓ 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）