Journal of Macromolecular Science Part A-Pure and Applied Chemistry
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2021
·
IF 2.168
Yanyang Gao,Wanqiu Liu,Liuyan Tang,Yanan Zhu,Jinqing Qu
As the laws about emission of volatile organic compounds (VOCs) become more and more stringent, low VOC content coatings, such as high solid polyurethane coating, gradually attract great attention. Herein, a series of star-shaped hydroxyl polyesters (SHPs) were synthesized by methyl hexahydrophthalic anhydride (MHHPA), diisopropanolamine (DIPA), and monoglycidyl ether. The number of their average molecular weights is ranged from 913 to 1390 with 1.55–1.75 of PDI. The viscosities of SHPs are low to 1060 mPa·s. The molecular structures of SHPs were characterized by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopies. The high-solid two-component polyurethane coatings (2 K-PU) from SHP-3 have a 65% of the solid contents and exhibit 20 mPa·s of the applied viscosity with 310 g/L of VOC contents. Moreover, the polyurethane film displays high coating hardness up to 2H, as well as excellent chemical resistance and good thermal stability.
研究领域:
高分子科学
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材料工程
·
涂料技术
·
环境化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 3
·1131-1142
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IF 1.289
Shitong Ren,Hefei Chang,Lijuan He,Xiaofei Dang,Yanyan Fang,Liaoyun Zhang,Huayi Li,Youliang Hu,Yuan Lin
A series of star block polymers with a hyperbranched core and 26 arms are successfully synthesized by atom transfer radical polymerization of styrene (St), and poly(ethylene glycol) methyl ether methacrylate from a hyperbranched polystyrene (HBPS) multifunctional initiator. All-solid polymer electrolytes composed of these multiarm star polymers and lithium salts are prepared. The influences of polyoxyethylene (PEO) side-chain length, PEO content, lithium salt concentration and type, and the structure of polymer on ionic conductivity are systematically investigated. The resulting polymer electrolyte with the longest PEO side chains exhibits the best ionic conductive properties. The maximum conductivity is 0.8 × 10 −4 S cm −1 at 25°C with EO/Li = 30. All the prepared multiarm star block polymers possess good thermal stability. The mechanical property is greatly improved owing to the existence of polystyrene blocks in the multiarm star polymer molecules, and flexible films can be obtained by solution-casting technique. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
材料科学
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高分子化学
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电化学
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高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
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2021
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IF 4.556
Wei Jia,Yinghuan Yang,Shuxing Liu,Lin Shi
Irradiation technology has been shown to be a possible preservation technology used to prolong the shelf life and provide microbial decontamination of spices. In this study, the molecular mechanisms of the irradiation-induced accumulation of polyphenols in star anise were explored using metabolomics combined with ultra-high-performance liquid chromatography quadrupole-Orbitrap (UHPLC-Q-Orbitrap) high-resolution mass spectrometry. Fifty-six star anise samples from different areas processed with 2–10 kGy doses of irradiation were compared. The effect of post irradiation storage times ranging from 0 to 70 days was also evaluated. A total of 161 metabolites with variable importance on projection greater than 1 were characterized, and significant differences in flavonoid content in star anise were observed after irradiation. Absolute quantification was used for the quantification of distinctive compounds, and the limit of quantitation of the components was 1.90–6.53 μg/kg. The flavonoid content was stable on the 28th day of storage. The average content of flavonoids increased by 2–9 times due to the breaking of glycoside bonds in star anise by irradiation. C 15 H 11 O 7 + m/z 303.13045 and C 3 H 3 O 2 + m/z 71.01276 were defined as the characteristic fragments of flavonoids according to the mechanism of fragmentation. Checking the extraction ion chromatogram (EIC) characteristic fragments allows straightforward screening of untargeted flavonoids.
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高影响因子
POLYMER BULLETIN
·
2021
·Vol. 79
·期 6
·4219-4231
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IF 2.87
Zhang Na,Wu Yansong,Li Yuying,Chen Liduo,Zhang Mingshui,Wang Jun
A novel star iminopyridyl ligand was synthesized in modest yield with 1.0 G star macromolecule and pyridine-2-carboxaldehyde as the raw materials. Reactions of the star iminopyridyl ligand with Fe(II), Co(II) and Ni(II) salts afforded metal complexes (Cat-Fe, Cat-Co and Cat-Ni) in good yields. The compounds were characterized by FT-IR, 1 H NMR, 13 C NMR, UV–Vis, ESI–MS and ICP-MS. In the presence of methylalumoxane (MAO), the iron, cobalt and nickel complexes have demonstrated higher ethylene oligomerization activity (up to 4.28 × 10 5 g/(mol Co h)), affording C 4 as the major product as well as C 6 , C 8 and C 10-18 oligomers. The catalytic activity was quite sensitive to the kind of species. The nature of solvent and co-catalyst significantly affected both the catalytic activity and product distribution. Moreover, the effect of oligomerization parameters (reaction temperature, [Al]/[Co] molar ratio, ethylene pressure) on the catalytic activity and the product distribution was investigated.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Pengli Zhang,Yanfang Zhao,Rentong Yu,Jianhe Liao
Six-arm star polycaprolactone with core of cyclotriphosphazene ( s -PCL) was synthesized via ring-opening polymerization and characterized by NMR and GPC . Epoxy thermosets incorporating 10–40 wt % of this copolymer were cured with 4,4′-methylenebis(2-chloroaniline) (MOCA) and 4,4′-diaminodiphenyl sulfone (DDS), respectively. In these thermosets, intermolecular specific interactions had a significant impact on their morphologies. Specifically, no discernable macroscopic phase separation was found in FESEM images of MOCA-cured epoxy resins . However, for the DDS-cured system, s -PCL was partially miscible with the epoxy thermosets, as evidenced with FTIR and DMA. This is may be owning to enriched concentration of hydroxyl groups in the s -PCL favored the miscibility between PCL subchains of carbonyl and the epoxy matrix. Dispersed phase, further confirmed by XRD to be amorphous , with a diameter of 0.34–0.44 μm could be observed ( s -PCL’ content ≤ 20 wt %) in this system. Nevertheless, crystallization of PCL could not be suppressed completely ( s -PCL’ content > 30 wt %). Besides, epoxy thermosets containing crystalline PCL were found to be more resistant to thermal degradation but sensitive to alkaline degradation (10% NaOH aqueous solution) according to TGA and FESEM results. This work presented here is a meaningful report on the presence of alkaline-labile crosslinking points through the whole networks.
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高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2017
·Vol. 218
·期 19
·1700148
·
IF 2.5
Pingping Wang,Shubo Cao,Yongbin Zhao,Tomokazu Iyoda,Aihua Chen
Detailed investigations on the self-assembly of amphiphilic star block copolymers composed of three-arm poly(ethylene oxide) (PEO) and poly(methacrylate) (PMAAz) with an azobenzene side chain (denoted as 3PEO- b -PMAAz) into stable spherical aggregates with clear lamellar stripes in solution are demonstrated. Four block copolymers, 3PEO 12 - b -PMA(Az) 33 , 3PEO 22 - b -PMA(Az) 31 , 3PEO 22 - b -PMA(Az) 62 , and linear PEO 68 - b -PMA(Az) 31 , are synthesized. The liquid crystalline properties of the block copolymers are studied by differential scanning calorimetry, polarized optical microscopy techniques, and wide-angle X-ray diffraction. The morphologies of the compound micelles self-assembled in tetrahydrofuran (THF)/water mixtures are observed by means of transmission electron microscopy and scanning electron microscopy. The size of the spherical micelles is influenced by the self-assembly conditions and the lengths of two blocks. The well-defined three-arm architecture of the hydrophilic blocks is a key structural element to the formation of stable spherical compound micelles. The micelle surface integrity is affected by the lengths of PEO blocks. The lamellar stripes are clearly observed on these micelles. This work provides a promising strategy to prepare functional stable spherical compound micelles self-assembled by amphiphilic block copolymers in solution.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
POLYMER BULLETIN
·
2014
·Vol. 71
·期 6
·1331-1347
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IF 1.491
Yuan Mingwei,He Zhengguo,Li Hongli,Jiang Lin,Yuan Minglong
Ring-opening polymerization of l -lactic acid O -carboxyanhydride was catalyzed by 4-dimethylaminopyridine in the presence of polyols pentaerythritol (PER) or dipentaerythritol (DPE). A high yield and relatively high molecular weight of 4- or 6-arm star PLA were obtained. The reaction was observed to be conducted easily and controllably. NMR analysis revealed that the end of the star PLA chain is a hydroxyl group and the central core is a PER or DPE group. The crystallinity of star PLA is lower than that of linear PLA. The crystallinity of 4-arm star PLA is lower than that of 6-arm PLA. Compared with that of 4-arm star PLA, the molecular arrangement of 6-arm star PLA may be relatively more regular.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 131
·期 16
·
IF 1.64
Xiu Qiang,Fang Chen,Xiao-Yan Ma,Xian-Bing Hou
Star-shaped polyhedral oligomeric silsesquioxane (POSS)–methacrylate hybrid copolymers with phenyl–triazole as terminal groups had been designed and synthesized via sequential atom transfer radical polymerization (ATRP), azidation, and phenylacetylene-terminated procedures, and the hybrid copolymers here could be denoted as POSS–(PXMA-Pytl) 8 , where X can be M, B, L, and S, represented four different methacrylate monomers, such as methacrylate (MMA), butyl methacrylate (BMA), lauryl methacrylate (LMA), and stearyl methacrylate (SMA), respectively. Thermal gravimetric analysis (TGA) and in situ Fourier transform infrared spectroscopy (FTIR) were applied for studying the thermal stability and degradation mechanism, and it was found that all of the POSS–(PXMA-Cl) 8 and POSS–(PXMA-Pytl) 8 copolymers exhibited excellent thermal stabilities, which had great potential in heat-resistant material application. Different tendencies of decomposition temperatures at 5% and 10% weight loss ( T 5 and T 10 ) dependent on the side-chain length and terminal group species were investigated respectively. The longer alkyl side chains of the monomers, the lower thermal stabilities, and enhanced T 5 and T 10 were also shown with the introduction of phenyl–triazole groups instead of chlorine groups. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40652.
研究领域:
聚合物化学
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材料科学
·
热分析
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DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2016
·Vol. 35
·期 1
·54-65
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IF 1.811
Chen Qi-jing,An Ze-sheng
A series of well-defined core cross-linked star (CCS) polymeric ionic liquids (PILs) were synthesized via a three-step approach. First, the styrenic imidazole-based CCS polymer (S-PVBnIm) was prepared by the RAFT-mediated heterogeneous polymerization in a water/ethanol solution, followed by the quaternization of S-PVBnIm with bromoalkanes and anion exchange. The CCS polymers were characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The obtained CCS polymers were used as the effective emulsifiers for oil-in-water high internal phase emulsions (HIPEs). Multiple oils with different polarity including n -dodecane, undecanol, toluene and octanol were emulsified using 0.5 wt% S-PVBnIm aqueous solution under the acidic condition to form HIPEs with long-term stabilities. The excellent emulsification properties of CCS PILs were demonstrated by HIPE formation for a variety of oils. The properties of HIPEs in terms of emulsion type and oil droplet size were characterized by the confocal laser scanning microscopy (CLSM). The intriguing capability of CCS PILs to stabilize HIPEs of various oils holds great potentials for the practical applications.
研究领域:
聚合物化学
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材料科学
·
胶体与表面化学
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高影响因子
International Journal of Nanomedicine
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2015
·
IF 4.383
Liang Qiu,Chun-Yan Hong,Cai-Yuan Pan
Redox-and pH-sensitive branched star polymers (BSPs), BP(DMAEMA-co-MAEBA-co-DTDMA)(PMAIGP)ns, have been successively prepared by two steps of reversible addition–fragmentation chain transfer (RAFT) polymerization. The first step is RAFT polymerization of 2-(N,N-dimethylaminoethyl)methacrylate (DMAEMA) and p-(methacryloxyethoxy) benzaldehyde (MAEBA) in the presence of divinyl monomer, 2,2′-dithiodiethoxyl dimethacrylate (DTDMA). The resultant branched polymers were used as a macro-RAFT agent in the subsequent RAFT polymerization. After hydrolysis of the BSPs to form BP(DMAEMA-co-MAEBA-co-DTDMA)(PMAGP)ns (BSP-H), the anticancer drug doxorubicin (DOX) was covalently linked to branched polymer chains by reaction of primary amine of DOX and aldehyde groups in the polymer chains. Their compositions, structures, molecular weights, and molecular weight distributions were respectively characterized by nuclear magnetic resonance spectra and gel permeation chromatography measurements. The DOX-loaded micelles were fabricated by self-assembly of DOX-containing BSPs in water, which were characterized by transmission electron microscopy and dynamic light scattering. Aromatic imine linkage is stable in neutral water, but is acid-labile; controlled release of DOX from the BSP-H-DOX micelles was realized at pH values of 5 and 6, and at higher acidic solution, fast release of DOX was observed. In vitro cytotoxicity experiment results revealed low cytotoxicity of the BSPs and release of DOX from micelles in HepG2 and HeLa cells. Confocal laser fluorescence microscopy observations showed that DOX-loaded micelles have specific interaction with HepG2 cells. Thus, this type of BSP micelle is an efficient drug delivery system.
研究领域:
材料科学
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药学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2015
·Vol. 4
·期 1
·141-151
·
IF 4.726
Liang Qiu,Qing Liu,Chun-Yan Hong,Cai-Yuan Pan
In order to develop pH- and redox-responsive unimolecular micelles composed of camptothecin (CPT)-conjugated hyperbranched star copolymers via acid-labile β-thiopropionate linkage, a new monomer, methacryloyloxy-3-thiohexanoyl–CPT, is synthesized through conjugation of CPT with methacrylate via β-thiopropionate linkage, and then used in synthesis of the CPT-conjugated hyperbranched star copolymers by two steps of atom transfer radical polymerization (ATRP): self-condensation vinyl polymerization of the CPT-based monomer, 2-hydroxypropyl methacrylate and inimer, and subsequent ATRP of oligo(ethylene glycol) methacrylate using the obtained hyperbranched polymers as the macroinitiator. The obtained polymers dissolve in water to form unimolecular micelles, and their release of CPT in water at various pHs and their anticancer efficacy are studied. The CPT-loaded unimolecular micelles with diameters of 3.56–6.08 nm are quite stable under neutral environment, and are easily triggered by mild acidic pH, such as 6.0 and 5.0. They can be easily internalized by the tumor cells, releasing the CPT. The CPT-conjugated unimolecular micelles via acid-labile β-thiopropionate linkage have potential for application as tumor-targeted drug release systems.
研究领域:
药物化学
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高分子化学
·
肿瘤治疗学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 18
·
IF 1.866
Fangyuan Guo,Wei Zhang,Xiaohong Pei,Xia Shen,Qinying Yan,Weiyong Hong,Gensheng Yang
With the growing number of therapeutic proteins on the market, effective delivery systems are receiving particular attention. In this study, biodegradable elastomers, intended for protein drug delivery and based on methacrylic tripoly(ε-caprolactone- co - d , l -lactide) cyclic ester with different ratios of ɛ-caprolactone to d , l -lactide and methacrylic bipoly[ɛ-caprolactone- b -poly(ethylene glycol)- b -ɛ-caprolactone], were synthesized and characterized. The degradation behavior, bovine serum albumin (BSA)-releasing kinetics, and cytotoxicity of the elastomers in vitro were investigated. The elastomers were degraded by the hydrolysis of the ester bond; this resulted in pH changes, which further affected the degradation rate. The BSA-releasing behavior was strongly dependent on the diffusion mechanism. In the diffusion-controlled period, nearly sustained and stable BSA release was achieved. Furthermore, the elastomers displayed good biocompatibility, as demonstrated by a 3-(4,5-dimethyl thiazol-2-yl)−2,5-diphenyl tetrazolium bromide assay and inflammation–induction experiments, and are considered promising candidates for the controllable delivery of protein drugs. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43393.
研究领域:
生物材料
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药剂学
·
生物医学工程
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DOI
高影响因子
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