COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 292
·期 10
·2633-2645
·
IF 2.41
Cong Houluo,Zheng Sixun
In this contribution, we reported the synthesis of poly( N -isopropylacrylamide)- block -poly(acrylic acid) (PNIPAAm- b -PAA) copolymer networks via sequential reversible addition-fragmentation chain transfer (RAFT) polymerization. The PNIPAAm- b -PAA block copolymer networks were characterized by means of Fourier transform infrared spectroscopy (FTIR) and small angle X-ray scattering (SAXS). The volume phase transition (VPT) temperatures of the PNIPAAm- b -PAA hydrogels were measured by means of micro-differential scanning calorimetry (micro-DSC). It was found that the block copolymer hydrogels displayed the VPT temperatures lower than the control PNIPAAm hydrogel. Compared to the control PNIPAAm hydrogel, the deswelling and reswelling properties of the block copolymer hydrogels were significantly improved. The improved thermoresponsive properties of the PNIPAAm- b -PAA hydrogels have been interpreted on the basis of the formation of the architecture of the block copolymer networks.
研究领域:
高分子化学
·
生物材料
·
药物递送
·
组织工程
·
智能响应材料
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
·
2018
·Vol. 56
·期 19
·1281-1286
·
IF 2.499
Yan Jie Wang,Chen Yu Li,Zhi Jian Wang,Yiping Zhao,Li Chen,Zi Liang Wu,Qiang Zheng
Development of tough hydrogels has greatly expanded their applications as load-bearing materials. However, the elastic modulus of tough hydrogels is usually lower than 1 MPa. It remains a challenge to design tough hydrogels with high modulus. We report here a series of tough double-network (DN) hydrogels with ultrahigh elastic modulus (up to 200 MPa) by forming robust hydrogen bonds between the first poly(acrylic acid) network and the second poly( N -isopropyl acrylamide) network. The dense cooperative hydrogen bonds greatly reduce the segmental mobility and thus improve the rigidity of gel matrix. Owing to the dynamic nature of hydrogen bonds, the modulus of hydrogels is strongly influenced by temperature and pH, affording the gels shape memory property. The strategy by forming robust noncovalent bonds between interpenetrating networks should be applicable to other systems for designing tough and versatile hydrogels with diverse promising applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56 , 1281–1286
研究领域:
高分子物理
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生物材料
·
软物质科学
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智能响应材料
·
组织工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 131
·期 9
·
IF 1.395
Chang Su,Dezhen Zong,Lihuan Xu,Cheng Zhang
In this article, semi-interpenetrating polymer network (Semi-IPNs) based on nitrile rubber (NBR) and poly(methyl methacrylate- co -butyl acrylate) (P(MMA-BA)) were synthesized. The structure and damping properties of the prepared Semi-IPNs blends were characterized and by fourier transform infrared spectrum (FTIR), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA/DTG), and tensile mechanical properties. The results showed that interpenetrating network based on P(MMA-BA) and NBR was successfully obtained, which showed the improved thermal stability compared to NBR/P(MMA-BA)-based two-roll mill blends. Furthermore, Semi-IPNs showed significantly better the dynamic mechanical properties than that of the two-roll mill system. With the increasing feed ratio of BA and MMA during the preparation of Semi-IPNs, the loss peak position for P(MMA-BA) in NBR/PMMA IPNs shifted to a lower temperature from 20°C to −17°C, and when NBR in Semi-IPNs was accounted for 40 wt %, the dynamic mechanical thermal analysis showed that much more advanced damping material with wider temperature range (−30°C < T < 80°C) as tan δ > 0.45 can be achieved. Therefore, it was expected as a promising way to obtain the excellent damping materials with good oil-resisted properties according the Semi-IPNs system. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40217.
研究领域:
高分子材料科学
·
功能材料
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复合材料
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材料物理
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阻尼材料
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聚合物改性
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2012
·Vol. 50
·期 23
·4871-4878
·
IF 3.919
Lijun Fan,Hou Chen,Zhihai Hao,Zhi Tan
A novel high oil-absorbing crosslinked gel was synthesized by copolymerization of butyl methacrylate (BMA) with a small amount of pentaerythritol triacrylate (PETA) crosslinker using single electron transfer-living radical polymerization (SET–LRP) initiated with carbon tetrachloride (CCl 4 ) and catalyzed by Cu(0)/hexamethylenetetramine (HMTA) in N, N-dimethylformamide (DMF). The polymerization followed first-order kinetics as indicated by linear increase of monomer concentration with reaction time. Effects of reaction temperature, crosslinker, initiator, and catalyst on the oil-absorbing properties of the crosslinked gel were investigated in detail. The oil absorptions of the crosslinked gel to chloroform, toluene could reach 51.9, 34.5 g/g, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
研究领域:
高分子化学
·
功能材料
·
环境修复
·
石油泄漏处理
·
聚合物科学
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2012
·Vol. 32
·期 6
·1699-1703
·
IF 2.686
Jing Ma,Hou Chen,Min Zhang,Chunhua Wang,Ying Zhang,Rongjun Qu
Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2′-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH) 2 ) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr 2 , an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr 3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared.
研究领域:
高分子化学
·
材料科学
·
催化化学
·
聚合物合成
·
功能材料
✓ 已验证
DOI
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2018
·
IF 3.112
Yurong Ma,Qingfeng Ban,Jingying Shi,Tiantian Dong,Cai-Zhong Jiang,Qingguo Wang
The effects of 1-methylcyclopropene (1-MCP) treatment, storage time, and shelf life and temperature on phenolic concentrations and antioxidant activity in apple peel and flesh of ‘Jonagold’ apple ( Malus domestica Borkh) have been investigated. Hyperoside and chlorogenic acid were the most abundant phenolic compounds in the peel and flesh, respectively. The flesh had lower concentrations of individual phenolics, total phenolics, flavonoids and lower antioxidant activity (determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay) than the peel. In addition, the profiles of phenolics as well as the changing patterns of individual phenolics also differed between the peel and the flesh. After long-time storage (180 d), the greatest decrease of concentrations was the concentrations of hyperoside (27 %) in the peel and total phenolics (35 %) in the flesh. Also, during the 90–180 d storage period, hyperoside and rutin in the peel, chlorogenic acid in the flesh, and flavonoids and antioxidant activity decreased in both peel and flesh tissues. Individual phenolics exhibited different stabilities during the early stages after harvest. 1-MCP reduced the reduction in the concentrations of hyperoside in the peel, chlorogenic acid in the flesh, and total phenolics, flavonoids and antioxidant activity in both the peel and flesh tissues during storage and shelf life. However, for quercetin and rutin, the protective effect of 1-MCP was only observed during the shelf life period. Overall, phenolic compounds responded variously to storage, shelf life, shelf temperature and 1-MCP treatment.
研究领域:
食品科学
·
植物生理学
✓ 已验证
产品关联
DOI
高影响因子
DESIGNED MONOMERS AND POLYMERS
·
2019
·
IF 1.528
Meng-Di Chen,Guo Zhang,Shi-Chang Chen,Xian-Ming Zhang,Wen-Xing Chen
In this study, 9-anthracenemethyl methacrylate (AMMA) and styrene (St) as monomers and benzoyl peroxide as an initiator were used to synthesize P(St-co-AMMA), a macromolecule tracer with a fluorescence effect, via free radical copolymerization. A fluorescent online detection device was built on the basis of the principle of fluorescence online detection by using the single-screw extrusion platform of a torque rheometer to explore the effect of the amount of macromolecular tracer and screw speed on the residence time distribution of polystyrene in single-screw extrusion. Fourier transform infrared spectroscopy, 1H-NMR, thermal stability, fluorescence properties, and rheological properties show that the resulting product P(St-co-AMMA) has a degree of thermal stability, fluorescence, and rheological properties similar to polystyrene, so this product can be used to characterize the residence time distribution during single-screw extrusion. The amount of macromolecular tracer P(St-co-AMMA) does not affect the residence time distribution of polystyrene during single-screw extrusion processing, meanwhile, the minimum residence time decreases and the residence time distribution becomes narrow as the screw speed increases, that is, the axial mixing capacity of the single-screw extruder decreases as the screw speed increases.
研究领域:
高分子化学
·
材料科学
·
聚合物加工工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiang Li,Huaili Zheng,Yili Wang,Yongjun Sun,Bincheng Xu,Chuanliang Zhao
Modified natural polymer flocculants has been the focus of research in environmental engineering field. Natural large molecular compound, chitosan (CTS) with many functional amino and hydroxyl groups can be easily modified to enhance its original functions. This work presents an environmentally friendly chitosan-based cationic polyacrylamide flocculants (CTS-g-PAMA) with enhanced function of sterilization and flocculation . CTS-g-PAMA was synthesized through Ultraviolet (UV)-initiated copolymerization. Structure characterization of FTIR, 1 H NMR, XRD and UV spectrum confirmed the successful grafting of AM and MAPTAC. Scanning electron microscopy (SEM) analysis results showed that CTS-g-PAMA exhibited a porous structure with a prodigious surface area. CTS-g-PAMA was then applied to treat a series of simulated waste water containing kaolin or Escherichia coli . Flocculation tests indicated that CTS-g-PAMA not only showed excellent flocculation effect but also showed high sterilization capability. A series of ONP concentration measurement tests through UV spectra analysis and 3D EEM analysis of suspension before and after flocculation were conducted to study sterilization mechanism, and results revealed the sterilization effect of CTS-g-PAMA was essentially bactericidal, not just antibacterial.
研究领域:
环境工程
·
高分子化学
·
水处理技术
·
材料科学
·
微生物学
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DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2015
·Vol. 33
·期 7
·976-987
·
IF 1.835
Li Mei,Li Gu,Zhang Zi-shou,Dai Xin,Yang Yue-wen,Mai Kan-cheng
To enhance the ultraviolet resistance of ZnO based polymer materials, ZnO-supported mesoporous zeolite (M-ZnO) was prepared and characterized by atomic absorption spectroscopy and scanning electron microscopy. The ultraviolet resistance, crystallization behavior and melting characteristics of ZnO and M-ZnO filled PPR composites were compared by FTIR spectra and differential scanning calorimetry. The ultraviolet resistance of M-ZnO filled PPR composites is higher than that of ZnO filled PPR composites, indicating higher ultraviolet resistance of M-ZnO than that of ZnO. The crystallization temperatures of mesoporous zeolite filled PPR were higher than those of M-ZnO and decreased with increasing UV-irradiation time. But the crystallization temperatures of M-ZnO filled PPR composites were not influenced by UV-irradiation time. The ZnO supported on the surface of zeolite is effective in enhancing the ultraviolet resistance of ZnO based polymer materials.
研究领域:
高分子材料科学
·
功能复合材料
·
材料老化与稳定性
·
纳米复合材料
·
聚合物改性
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
He Chen,Liang Kong,Yong Wang
Activation by nitric acid oxidation has been combined with atomic layer deposition (ALD) to modify microporous polypropylene (PP) membranes. Nitric acid oxidation with prewetting of t -butanol generates active groups on the inert surface of PP membranes. Metal oxides including Al 2 O 3 and TiO 2 are subsequently ALD-deposited on the activated membrane. Nitric acid oxidation is a mild approach to activate PP membranes. A short immersion in nitric acid for 10 min is able to generate oxygen/nitrogen-containing active species on the membrane surface , which leads to an evident increase (38%) in the membrane permeability. The mechanical stability and the integrity of the porous structure are well preserved after activation. Surface elemental analyses and microscopy observations confirm the successful deposition of metal oxides thin layers onto the activated membranes. In the deposition of either Al 2 O 3 or TiO 2 , the hydrophilicity of the deposited membranes is continuously improved with increasing ALD cycles, resulting in further increase in water flux. After 100 ALD cycles, the flux is doubled compared to that of the bare membrane. Al 2 O 3 is more efficient in enhancing the hydrophilicity and permeation than TiO 2 under identical deposition conditions because of the faster growth of Al 2 O 3 on the activated PP surface.
研究领域:
材料科学
·
膜技术
·
表面化学
·
高分子化学
·
化学工程
✓ 已验证
DOI
高影响因子
DESIGNED MONOMERS AND POLYMERS
·
2019
·
IF 1.528
Shuang Li,Yazhen Wang,Liqun Ma,Xueze Zhang,Shaobo Dong,Li Liu,Xilai Zhou,Chenglong Wang,Zhen Shi
The reverse atom transfer radical polymerization (RATRP) of acrylonitrile (AN) was carried out in N, N-dimethylformamide (DMF) with AIBN as initiator, FeCl3•6H2O/triphenylphosphine (PPh3) and FeCl3•6H2O/pentamethyldle-thylenetrlamlne (PMDETA) as catalytic systems, respectively. Effect of reaction time and initiator concentration on polymerization rate, molecular weight and molecular weight distribution were investigated in detail. The Fourier transform infrared spectrometer (FTIR) and 1H nuclear magnetic resonance spectroscopy (1HNMR) were employed to analyze the chain end of the PAN. Gel permeation chromatography (GPC) was applied to measure the molecular weight and polydispersity index (PDI) of PAN. The polymerization demonstrated a typical pseudo first-order kinetics characteristics as evidenced by the number-average molecular weights (Mn) increasing linearly with monomer conversion; the Mn decreasing with the increasing of the initiator concentration. Meanwhile, the low PDI value (<1.2) indicated the controllability of polymerization.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 9
·4604-4609
·
IF 2.936
Lei Lü,Hongming Lou,Yinglin Xiao,Guangzhao Zhang,Chaoyang Wang,Yonghong Deng
Triblock copolymer polydopamine-polyacrylic-polyoxyethylene (PDA-PAA-PEO) with excellent performance as a binder for silicon anodes was synthesized. Its structure was confirmed by 1H-NMR, FTIR and UV-vis spectroscopy. Results of electrochemical measurements indicated that a silicon anode based on PDA-PAA-PEO binder exhibited excellent cycle performance with a reversible capacity of 1597 mA h g−1 after 200 cycles at a current density of 0.5 C, much better than that of an electrode based on a polyvinylidene-fluoride binder. Improvement of the cycle performance and reversible capacity for silicon anodes could be attributed to the strong adhesive and high ion conductivity of PDA-PAA-PEO.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米材料
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）