POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 58
·期 9
·1523-1529
·
IF 1.449
Yusheng Dong,Jizong Chen,Fredrick Nzioka Mutua,Yuanbo Gao,Tingting Yang,Yong He
To modify the properties of poly(hexamethylene oxamide) (PA62), amine-terminated polyoxypropylene glycols (PGs) were introduced into the polyoxamide main chain as soft segments. A series of PA62/PG2 copolymers were synthesized successfully by a two-step method. Fourier transform infrared spectroscopy, solution proton nuclear magnetic resonance spectroscopy ( 1 H-NMR), differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction were used to analyze the structures and to investigate the properties of these copolymers. The saturated water absorption was also evaluated by gravimetric analysis for PA62/PG2 copolymers. The results revealed the incorporation of PG2 effectively modified the properties of PA62 and the copolymers with PG2 content of 10–20 mol% possessed high melting point (293°C–314°C), good thermal stability and low saturated water absorption. POLYM. ENG. SCI., 58:1523–1529, 2018. © 2017 Society of Plastics Engineers
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 19
·e53829
·
IF 3
Xin Kang Li,Jun Wei Shen,Hai Lan Lin,Zhao Xin Zhang,Xun Tao Zhang,Jun Bian,Dai Qiang Chen
In order to explore effective strategies to fabricate main-chain polybenzoxazine (PBZ) thermosetting resin for structural material applications, here, five PBZ with different molecular structures, that is, poly(Co-ddm), poly(Co-BPA-ddm-Co) main , poly(Ph-BPA-ddm-Co) main , poly(Ph-BPA-ddm-Ph) main and poly(Ph-ddm) were designed, synthesized and compared by introducing unsaturated fatty chains through the Mannich reaction with cardanol. The structure and properties of five PBZ with different structure were systematically investigated by using Fourier transform infrared (FTIR), NMR, water absorption and mechanical tests. FTIR and NMR tests indicated that five PBZ with different molecular structures were successfully synthesized. The mechanical tests indicated that the impact strength of the double-capped cardanol-based main-chain PBZ was 243% higher than that of the traditional PBZ. The water absorption of main-chain PBZ was higher than that of diamine PBZ, and the water absorption of poly(Ph-BPA-ddm-Co) main was the lowest in the main-chain PBZ. Based on the experimental results, five PBZ amorphous cells with different structures were successfully established. It indicated that the main chain PBZ showed better thermomechanical properties than the traditional diamine PBZ due to high crosslinking conversion and hydrogen bond density. Moreover, the modulus and glass transition temperature of the main chain structure containing unsaturated fatty chains did not decrease significantly.
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
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Yi Zhang,Cheng Peng,Gang Wang,Xinrong Huang,Yingfeng Yu
Fabricating epoxy resins low in both dielectric properties and moisture absorption is of emerging need but challenging, especially in the application of microelectronic packaging materials that are intensively exposed to harsh environments. In this work, a series of diphenols of different substituent positions and groups blocked with ester groups were copolymerized with diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin to synthesize high-molecular-weight hydroxyl-free epoxy thermoplastics (phenoxy resins). Remarkably low dielectric constants down to 2.26 at 1 MHz and low dielectric losses were found in these hydroxyl-free epoxy thermoplastics, which also showed excellent hydrophobicity compared with those of epoxy thermosets and commercialized epoxy thermoplastic. The migration of ester groups in the polymerization process was studied by a series of model reactions, indicating that the reaction mainly undergoes an associative mechanism under catalysis of the imidazole derivative. In addition, the polymers demonstrated good thermal stability, while thermal properties can be easily modulated by changing the substituent group of phenolic ester monomers. In short, these hydroxyl-free epoxy thermoplastics could be a promising candidate for antimoisture microelectronic packing materials and have versatile applications.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Yue Gong,Teng Fu,Xiu-Li Wang,Yu-Zhong Wang
Polymer dielectric materials in high-frequency communication applications needs to meet strict requirements, and the future development trend is high performance and environmental friendly materials. Herein, we propose a design strategy for simultaneously adjusting multiple performances by building blocks (naphthyl, diphenyl ether , and phenyl). The synthesized copolyester containing phenylene ether structures exhibits good comprehensive properties, including high thermal stability (the temperature at 5 wt% weight loss, 475–495 °C) and inherent flame retardancy (limiting oxygen index 37.8 %∼40.1 %, UL-94 V-0 level), low water absorption (0.16 %∼0.46 %), low dielectric constant (3.04–3.31 @10 GHz) and low dielectric loss (0.0020–0.0028 @10 GHz). The crankshaft naphthyl and bent diphenyl ether structures together change the free volume or spacing of polymer chains, thereby effectively affecting the density or motility of the polarizable groups. These aromatic structures also possess high charring-ability, thus enabling the polymers with the inherent high flame retardancy. Since only carbon, hydrogen, and oxygen elements are introduced into the copolyesters, it supplies a solving approach to eliminate the potential chemical concern arising from introducing heteroatoms such as halogen or phosphorus into polymers.
研究领域:
高分子材料科学
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材料化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Express
·
2023
·Vol. 13
·期 10
·1665-1673
·
IF 0.7
Jin Junqi,He Qiao,Li Shuqin,Zhou Xuan,Fang Yongqiao
The absence of organic solutions during the preparation of waterborne polyurethane has resulted in a decline in its overall performance. To address this issue, this study introduces nano zirconia as a modifier to enhance the properties of the polyurethane material. A novel composite
material combining waterborne polyurethane and zirconium oxide nanoparticles (ZrO2 NPs) was proposed, and its performance was experimentally analyzed. The particle size of ZrO2@CA is as high as 80 nm, which exceeds the 23 nm of ZrO2@MA and the 21 nm of ZrO2@AA.
Transmission electron microscopy reveals that the emulsion droplets in the composite lotion exhibit excellent spherical uniformity and dispersion. Moreover, there is not a significant difference in size between composite lotions with different zirconia contents. Remarkably, even with a zirconia
content of only 0.5 wt%, the specimen exhibits high mechanical properties, with the tensile strength increasing from 11.9 MPa to 14.3 MPa and the elongation at break increasing from 560% to 712%. Additionally, a higher doping amount of ZrO2 leads to an increased water absorption
rate, with the actual water absorption rate rising from 7% to 14.4%. In practical engineering projects A and B, the initial water output of four holes in engineering A is maintained at 48–580 m3/h. However, as time progresses, the water output gradually decreases, approaching
0 m3/h. In project B, the composite material coating exhibits a tensile strength greater than 15 MPa, reaching 18.26 MPa, which significantly surpasses the performance of the comparison material. Overall, the composite materials demonstrate excellent mechanical and water protection
properties, proving to be crucial for practical water inrush protection applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Shuai Zhang,Xiaofeng Li,Yanqin Yang,Jingde Li,Jifu Zheng,Suobo Zhang
The Development of high-efficiency anion exchange membrane water electrolyzers (AEMWEs) depends on a well-designed anion exchange membrane (AEM) that possesses good mechanical robustness, high alkaline stability, and enhanced ionic conductivity. Herein, we use tetraphenylmethane as a branched monomer to create AEMs with branched structure based upon poly(aryl piperidinium)s. When five molar percentage of tetraphenylmethane is incorporated, the quaternized poly( p -terphenyl-tetraphenylmethane-piperidinium) membrane (QPTTP-5%) exhibits low water swelling ratio (8.53% at 80 °C) and decent mechanical strength (31.95 MPa). Meanwhile, the high microporosity and obvious microphase separation behavior of the as-developed QPTTP-5% membrane engendered by the rigid and tetrahedral tetraphenylmethane branched structure improve hydroxide conductivity, reaching 164.70 mS cm −1 at 80 °C. Moreover, the current density of the AEMWE single cell comes up to 1500 mA cm −2 at 2.2 V and 80 °C with the implementation of QPTTP-5% membrane. This study reveals that the introduction of a rigid and three-dimensional branched structure is conducive to the preparation of high-performance AEMs with microporous structure and low swelling ratio.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
YuMei Luo,QingGuo Shang,Hua Hu,Xiaodong Bai
In order to reduce the economic loss caused by well leakage and the lag of drilling progress, it is very important to use plugging materials reasonably and effectively. Expandable polymer materials can better fill cracks and holes of different sizes by absorbing water expansion and deforming. In this article, an expandable polymer plugging agent (PSMAN) was prepared by soap-free emulsion polymerization using methyl methacrylate (MMA), styrene (St), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) as reaction monomers, N -hydroxymethyl acrylamide (NMA) as a cross-linking agent, and ammonium persulfate (APS) as initiator. The optimal synthesis conditions were determined by designing the orthogonal experiments, and the various properties of the materials were tested and evaluated. The experimental results show that PSMAN has good high temperature resistance, spherical structure, and median particle size of 15.099 μm, and the water absorption rate of room temperature at 24 h reaches 37.8 g/g, and pressure bearing capacity can reach 5 MPa. The addition of polymer to water-based drilling fluid can increase the viscosity of drilling fluid and improve the rheological properties of drilling fluid by a small amount. Under normal temperature and medium pressure, the polymer can form a dense film on the surface of the mud cake, thereby reducing the filtration of drilling fluid and effectively improving the stability of the wellbore.
研究领域:
材料科学
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石油工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Junqing Qian,Yan Chen,Haiyan Yang,Changyan Zhao,Xiaohua Zhao,Hui Guo
In order to develop starch hemostatic materials with excellent hemostatic properties, the preparation of crosslinked porous starch (SPS) with sodium trimetaphosphate (STMP) as cross-linking agent was studied in this paper. When the solid-liquid ratio of porous starch (PS) was 30%, the mass ratio of cross-linking agent to starch was 0.04–1, and the SPS was crosslinked at pH 10.0, 55 °C for 50–60 min, the water absorption ratio and swelling ratio of SPS reach up to 160.5% and 239.1%, respectively. The characterization by infrared spectra, scanning electron microscopy and X-Ray diffraction spectra confirmed that the structure of SPS is similar to that of PS. The degradation experiment in vitro indicated that the degradation effect of PS was better than that of SPS. The whole blood coagulation kinetics experiment showed that SPS could promote the formation of blood clot, and the adsorption experiment of red blood cells in vitro showed that SPS could adsorb red blood cells. The average hemostasis time of SPS in tail amputation 1 cm and liver laceration were 181.03 s and 179.30 s.
研究领域:
生物材料学
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医学工程
·
药剂学
✓ 已验证
DOI
高影响因子
Minerals
·
2019
·Vol. 9
·期 12
·731
·
IF 2.25
Lihua Peng,Shan Qin
Porcelain tiles are a building material that has been widely used in recent years and that consumes substantial resources during the sintering process. This study reports on the production of low-temperature porcelain tiles by using low-grade lithium ore (LO) and silica crucible waste (SCW) in a new SiO2–Al2O3–Na2O–K2O–Li2O system. The firing temperature of the porcelain tiles was reduced from 1260 °C to 1070 °C by adding 30% LO instead of feldspar in a modified triaxial ceramic body, and SCW was recycled and used as a raw material. These actions help to reduce the carbon emissions produced during sintering and achieve sustainable development. The effect of phase transitions on the sintering and technological properties of the porcelain tiles was studied by quantitative phase analysis, using X-ray diffraction (XRD). Secondary mullite (0–19%) can be formed at 1040–1100 °C, where more quartz and cristobalite will be retained, which increases the rupture modulus of the porcelain tiles. While the vitreous phase increases rapidly at 1100–1160 °C, the closed pores (0.1–33.1%) will simultaneously expand, causing a decrease in compactness. The results show that low-grade LO (with a cost similar to that of feldspar) allows for the production of porcelain tiles with better process performance at lower temperatures (≤1100 °C).Keywords:porcelain tiles;lithium ore;silica crucible waste;firing temperature;water absorption;rupture modulus
研究领域:
材料科学
·
可持续发展
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2024
·Vol. 39
·期 1
·82-90
·
IF 1.3
Chen Meihua,Liu Rongjin,Chen Ping,Jing Daiyan,Wan Dandan,Fu Siyuan
Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete. An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using sodium carboxymethyl starch (CMS) with high hydrophilicity, acrylic acid (AA) containing anionic carboxylic group and acrylamide (AM) containing non-ionic amide group as the main raw materials. The results show that the ratio of CAA-ICA alkali absorption solution is higher than that existing ICA, which solves the low water absorption ratio of the ICA in alkali environment. The water absorption ratio of CAA-ICA in saturated Ca(OH) 2 solution is 95.8 g·g −1 , and the alkali tolerance coefficient is 3.4. The application of CAA-ICA in cement-based materials can increase the internal relative humidity and miniaturize the pore structure. The compressive strength of mortar increases up to 12.95% at 28 d, which provids a solution to overcome the reduction of the early strength.
研究领域:
土木工程
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材料科学
·
建筑材料
·
高分子科学
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2018
·
IF 3.485
Weipeng Zhang,Xu Yao,Santosh Khanal,Shiai Xu
In this study, bamboo flour (BF) was chemically modified using alkyl ketene dimer (AKD) or alkali treatment for the preparation of high-density polyethylene/bamboo flour (HDPE/BF) composites with or without compatibilizer maleic anhydride grafted high-density polyethylene (HDPE- g -MAH). The modified BF was characterized by Fourier transformation infrared (FTIR) spectroscopy and contact angle measurement, and the mechanical properties, morphology and water resistance of the HDPE/BF composites were investigated and compared. The results show that highly hydrophobic BF can be obtained by a simple procedure using a common paper sizing agent AKD. AKD can react with the hydroxyl groups in cellulose to form β-keto ester. The combination of AKD treatment and addition of HDPE- g -MAH is more effective in improving the mechanical properties of HDPE/BF composites than using them alone. The impact strength, flexural strength and modulus of HDPE/A-BF/MAH composite are increased by 100.0%, 197.1% and 61.8% compared with that of HDPE/U-BF composites, and the water absorption and thickness swelling are decreased by 87.7% and 87.4% after immersion in water for one week, respectively. These results indicate that HDPE/BF composites with good mechanical properties and high water resistance can be obtained by AKD treatment.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2022
·Vol. 57
·期 9
·5827-5836
·
IF 3.612
Chongxue Hu,Yingquan Zhang,Clyde Don,Bo Zhang,Boli Guo
Summary Four extruded noodles with same variety wheat flour mill streams (FMS) from the centre to the outer layer of the endosperm and 1 round or 3 rounds of extrusion have different quantity and rheological properties of glutenin macropolymer (GMP). The results showed that the GMP content and the G' plateau value of GMP-gel of the extruded noodles were 0.074 ~ 0.093 [g/(g noodle)] and 575 ~ 1895 Pa, respectively. Meanwhile, the freezing water content, the cooking loss, the textural hardness and the springiness of the extruded noodles were 11.4 ~ 19.5 [g/(100 g water)], 1.7 ~ 2.0 [g/(100 g water-insoluble noodle)], 5378 ~ 6112 g and 83.4 ~ 90.8%, respectively. Compared to 1 round, extruded noodle with 3 rounds extrusions had slowly decreasing G' with strain increasing, a significantly low freezing water content and cooking loss ( P < 0.05) and high hardness. Extruded noodle with high G' in GMP-gel had relatively high springiness.
研究领域:
食品科学
·
生物化学
✓ 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）