MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2019
·Vol. 220
·期 12
·1900061
·
IF 2.622
Liang Zhao,Lin Zhang,Zelai Zheng,Ying Ling,Haoyu Tang
Homopolypeptide bearing azobenzene and triethylene glycol spacers, and 1-butylimidazolium pendants, namely P(Azo-OEG 3 -ImX) (X = Cl, I, BF 4 ) are prepared by 1,3-dipolar cycloaddition and subsequent ion-exchange reaction. Both 1 H NMR and FTIR confirm the polymer structures and reveal a high grafting efficiency (97%). P(Azo-OEG 3 -ImI) shows reversible upper critical solution temperature (UCST)-type thermoresponsive property in ethanol while P(Azo-OEG 3 -ImI/BF 4 ) shows a UCST in ethanol/water solvent mixtures. P(Azo-OEG 3 -ImI) shows UCST-type phase transitions in ethanol or ethanol/water solvent mixtures. After UV irradiation, the UCST-type cloud point temperature ( T cp ) remains constant in ethanol. However, it decreases after UV irradiation and increases after visible light irradiation in ethanol/water solvent mixtures due to the trans – cis isomerization of azobenzene moieties. P(Azo-OEG 3 -ImCl/I) shows NaI-induced UCST in water. The T cp of the P(Azo-OEG 3 -ImCl/I) aqueous solution is highly related to the polymer/salt concentration and nature of counteranions. P(Azo-OEG 3 -ImCl) also shows reversible light-responsive properties in NaI aqueous solutions. Higher NaI concentration is needed to induce a UCST for P(Azo-OEG 3 -ImCl) after UV irradiation. Moreover, ciprofloxacin-loaded hydrogel containing P(Azo-OEG 3 -ImCl) shows more efficient drug release while the UV irradiation leads to slightly low drug release.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Wenjing Hu,Yuting Zhang,Ying Zhou,Yan Zhang,Shuguang Han
Due to the high mean degree of polymerization (mDP) of condensed tannins, condensed tannin-based adhesives have high viscosity, poor water resistance, and low shear strength, and thus are limited in their application. Degradation of tannins to reduce its mDP is a feasible method to solve the above problems. In this study, photocatalytic degradation of larch tannins (LT) was carried out to obtain LT with different mDP. Larch tannin-formaldehyde (LT-F) adhesives were prepared with different mass ratios of F to LT, and then used to prepare plywood with poplar veneer. The effect of different mDP of LT and different mass ratios of F to LT on the properties of the LT-F adhesives were explored. The results showed that LT with different mDP could be obtained by photodegradation. When the photodegradation time was 6 h (LT6, with mDP 3.71), and the mass ratio of F to LT6 was 10 %, the LT6–10 %F adhesives had low viscosity, good water resistance, and high shear strength that exceeded the requirements of the Chinese national standard (GB/T9846–2015, ≥ 0.70 MPa). The formaldehyde emission was 0.15 mg/L, lower than poplar veneer (0.23 mg/L). Therefore, LT6–10 %F adhesives can still be safely used in wood industry although formaldehyde is used.
研究领域:
林产化学与技术
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2018
·
IF 5.914
Wangmeng Hou,Yuan Feng,Baohui Li,Hanying Zhao
A combined computer simulation and experimental study on coassembly of poly(2-(dimethylamino)ethyl methacrylate)-block-polystyrene (PDMAEMA-b-PS) block copolymers and PS brushes on silica particles was performed. PS brushes on silica particles at two different grafting densities were prepared by the “grafting to” approach, and PDMAEMA-b-PS block copolymers with different molecular weights and compositions were synthesized by reversible addition–fragmentation chain transfer polymerization. In THF/methanol mixtures, block copolymer chains and PS brushes coassemble into surface micelles (s-micelles), with collapsed PS cores and PDMAEMA coronae. Meanwhile, block copolymer chains are able to self-assemble into block copolymer micelles (b-micelles). Computer simulation results and experimental results indicate that block copolymer concentration, PS and PDMAEMA block lengths, and PS grafting density exert significant influences on the coassembly process. In low BCP concentration regime, the average size of s-micelles increases with BCP concentration and keeps unchanged at high concentration. The PS block length has a significant influence on the size of s-micelles. The average size increases with an increase in PS block length. For a BCP with long solvophilic PDMAEMA block, it is energy favorable to self-assemble into b-micelles, but to coassemble into s-micelles. With an increase in PDMAEMA block length, the morphology of the s-micelles changes from wormlike/spherical structures to spherical structures and to smaller spherical structures. The average size of the s-micelles coassembled by PS brushes at a lower grafting density is smaller than those coassembled by PS brushes at a higher grafting density.
研究领域:
材料科学
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高分子化学
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计算机模拟
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 18
·47405
·
IF 2.188
Guorong Qiu,Wenshi Ma,Yuanqi Jiao,Li Wu
Low-dielectric-constant aromatics, homopolyimide and copolyimide, were introduced. Homopolyimides were prepared by pyromellitic dianhydride (PMDA) as an anhydride monomer and 4,4′-oxydianiline (ODA), 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as an amine monomer. The copolyimides were prepared with PMDA as an anhydride monomer, ODA as an amine monomer with the addition of 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as another amine monomer. The polyimides were well characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, thermomechanical analysis, dielectric measurements, and tensile testing. The homopolyimide and copolyimides showed lower dielectric constants than the homopolyimide formed by ODA and PMDA. The results also indicate that the interchain distance, the quantities of phenyl ether, and the position of the substitute are factors that not only affected the thermal performance of polyimide by improving the molecular flexibility but also reduced the dielectric constant of polyimide by increasing the free volume of the molecular chain and decreasing the polarization points per unit volume. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47405.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 8
·5801-5807
·
IF 4.6
Zeen Zhang,Tianjiao Li,Yong Dong,Yangcheng Lu
This study focuses on ethylene homopolymerization catalyzed by α-diimine catalysts within a designed microfluidic system. Distinct from conventional batch reactors, this microfluidic configuration effectively eradicates the reaction environment heterogeneity, thereby guaranteeing homogeneous reaction conditions and decoupling the mass transfer from the reaction process. This unique setup enables precise modulation of ethylene concentration, facilitating the isolation of variables to scrutinize the effects of temperature and pressure on the polymerization. By varying residence times, it's revealed that the reaction rate is ethylene concentration-independent. Variable separation studies between concentration and temperature show an inverse relationship between temperature and branching degree (BD), contrasting traditional batch reactions due to ethylene concentration changes. Pressure studies indicate that higher pressure leads to lower BD. Different product structures' steric hindrances influence the reaction rate; greater hindrance slows it down. These novel findings suggest microreactors offer new perspectives on late transition metal-catalyzed ethylene homopolymerization, potentially enabling breakthroughs in mass production.
研究领域:
化学工程
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高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2025
·
IF 3.2
Haohao Hou,Yu Xue,Meng Zhang,Xin He,Hongfu Zhou,Liyang Zhang
Polypropylene homopolymer (PPH) is a highly practical and widely utilized thermoplastic polymer that finds extensive applications in automotive components, piping systems, and constructed materials. Although PPH has merits such as low cost, versatility, and exceptional corrosion resistance, its low toughness limits application in specialized engineering sectors such as high-pressure piping, aerospace components, and cryogenic environments. In this paper, the toughness of PPH was improved by blending with polypropylene block copolymer (PPB) and β nucleating agent (NP-328). The room temperature impact strength of PPH containing 30% PPB and 0.2% NP-328 was increased by 4.4 times, and its low-temperature elongation at break was improved by 87%, compared to those of the pure PPH sample. Furthermore, this paper investigated the crystallization behaviors of PPH/PPB(70/30) with varying amounts of NP-328, using crystallization kinetics studies for analysis. The crystallization rate of PPH/PPB (70/30) systems gradually adding the amounts of NP-328 improved significantly. At 140°C, the half-crystallization time of the PPH/PPB (70/30) containing 0.2% NP-328 decreased by 14.5 min compared with that of PPH/PPB (70/30) without NP-328. The high-toughness PPH material developed in this work exhibits significant potential for application across a variety of industries, including automotive manufacturing, home appliance production, and packaging sector, among others. Highlights IS of polypropylene homopolymer (PPH) increased from 19.1 to 103.2 kJ/m2. Crystallinity of β in PPH/polypropylene block copolymer (PPB) growed to 26.8%. Low temperature toughness of PPH increased by about two times. The t1/2 of 70PPH/30PPB/0.2β was 14.5 min shorter than 70PPH/30PPB at 140 °C.
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
iScience
·
2024
·
IF 4.6
Zhiyong Wu,Jiacheng Luo,Luyang Li,Qingshu Dong,Xiaohui Zhang,Zili Li,Yadong Liu,Shengxiang Ji,Weihua Li,Yan Zhang,Shisheng Xiong
Directed self-assembly (DSA) lithography has demonstrated significant potential in fabricating integrated circuits. However, DSA encounters limited processing windows due to the requirement for precise matching between the period of block copolymers (BCPs) and graphoepitaxy templates. We propose a binary BCP/homopolymer blending strategy to manipulate the self-assembly behavior and the processing window of graphoepitaxy DSA in contact hole shrinking. By carefully tailoring the blending rates of poly(methyl methacrylate) (PMMA) with different molecular weights in cylindrical polystyrene- b -poly(methyl methacrylate) (PS- b -PMMA), we manipulate the period and morphology of BCP/homopolymer self-assembly. Specifically, we employ BCP/homopolymer blending to fine-tune the critical dimension (CD) of contact holes with PS-affined topographical templates. Subsequent pattern transferring is achieved by selectively etching defect-free shrinkable cylinders as hard masks. Furthermore, self-consistent field theory (SCFT) simulation was employed to explore the self-assembly of BCP/homopolymer blending in confined cylindrical space and the results were in good consistency with the experimental results.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2020
·
IF 4.231
Ke Wang,Qi Liu,Guiyan Liu,Yongfei Zeng
The study of thermoresponsive homopolymers has attracted great attention due to their broad application value. Herein, a series of novel thermoresponsive homopolymers of poly[oligo(ethylene glycol) (acyloxy) methacrylate]s containing oligo(ethylene glycol) (OEG) units and substituent groups of ester have been designed and prepared by RAFT polymerization . The solution properties of these polymers have been investigated in detail, which indicate that most of them exhibit lower critical solution temperature (LCST) in water and upper critical solution temperature (UCST) in alcohols, and their LCST-type or UCST-type cloud point temperature ( T CP L or T CP U ) is closely related to the OEG units and ester groups. Furthermore, the parameters affecting the thermoresponse of these polymers including polymerization degree (DP) and concentration have also been investigated. The present work not only discovers a series of novel thermoresponsive polymers, but also has certain guiding significance on the understanding of molecular structure and thermoresponsive property relationships, which is useful for the design of new thermosensitive polymers.
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
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Peixuan Lei,Yaying Yu,Fenrou Chen,Xiaoling Chen,Yuxiao Wu,Haibin Wu,Fan Yang,Lin Zhou
Schizophyllan (SPG), a polysaccharide produced from Schizophyllum commune ( S. commune ), is recognized for its diverse biological functions, such as antioxidant and anti-inflammatory properties. Despite these potential benefits, research into its application in wound repair remains limited, particularly regarding non-homopolymeric SPG. This study utilized liquid fermentation with the S. commune 5.43 to produce SPG. In vitro studies examined the effects and mechanisms of SPG on the proliferation, migration and antioxidant stress of HaCaT and HUVEC cells. In vivo , full-thickness skin wound model was created in BALB/c mice to evaluate SPG's wound healing effects. The results indicated that SPG significantly promoted the proliferation of HaCaT and HUVEC cells and enhanced HUVEC cells migration. It also promoted the expression of cell cycle regulatory factors, ECM remodeling and antioxidant-related genes, while reducing oxidative stress induced by H₂O₂. In vivo , SPG outperformed 3 M hydrogel dressing, achieving a 96.65 % wound healing rate in BALB/c mice, significantly improving wound healing and epithelialization. In summary, SPG may promote wound healing through mechanisms such as regulating the cell cycle, facilitating ECM remodeling, and enhancing the expression of antioxidant genes. These findings provide a foundation for the application of SPG in skin repair and emphasize their potential as natural therapeutics for wound healing and tissue regeneration.
研究领域:
生物医学
·
微生物学
·
药理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 38
·期 4
·349-356
·
IF 2.804
Yang Bo,Du Jian-Zhong
Noninvasive ultrasound is a more effective strategy for on-demand drug delivery of polymeric nanoparticles than many other stimuli. However, the preparation of ultrasound-responsive homopolymer nanoparticles is still very challenging. In this study, we disclose the regulating factors of ultrasound responsiveness of homopolymer nanoparticles and the disaggregation behavior of homopolymer nanoparticle aggregates. Homopolymer nanoparticles such as vesicles and large compound micelles (LCMs) are self-assembled from poly(methoxyethyl methacrylate) (PMEMA) and poly(amic acid) (PAA), respectively. The ultrasound responsiveness of PAA vesicles at metastable state could be regulated by tuning the self-assembly temperature ( T s ), and was optimized when T s is around the glass transition temperature ( T g ) of PAA. However, the PMEMA LCMs did not respond to ultrasound as they are at stable state. On the other hand, poly(2-(2-ethoxyethoxy)ethyl acrylate) (PEEA) could self-assemble into vesicle aggregates or complex micelle aggregates, which were dissociated upon sonication. Overall, the above findings provide us with a fresh insight for designing ultrasound-responsive polymeric nanoparticles.
研究领域:
材料科学
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生物医学工程
·
药学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2012
·Vol. 50
·期 9
·1834-1843
·
IF 3.919
Ye Liao,Chang-Ming Dong
Thermosensitive diethylene glycol-derived poly( L -glutamate) homopolypeptides (i.e., poly- L -EG 2 -Glu) with different molecular weights (MW) ( M n,GPC = 5380–32520) were synthesized via the ring-opening polymerization (ROP) of EG 2 - L -glutamate N -carboxyanhydride (EG 2 -Glu-NCA) in N , N -dimethylformamide solution at 50 °C. Their molecular structure, conformation transition, liquid crystal (LC) phase behavior, lower critical solution temperature (LCST) transition, and morphology evolution were thoroughly characterized by means of FTIR, 1 H NMR, gel permeation chromatography, differential scanning calorimetry, wide angle X-ray diffraction, polarized optical microscope, transmission electron microscope, and dynamic light scattering. In solid state, the homopolypeptide poly- L -EG 2 -Glu presented a conformation transition from α-helix to β-sheet with increasing their MW at room temperature, while it mainly assumed an α-helix of 80–86% in aqueous solution. Poly- L -EG 2 -Glu showed a thermotropic LC phase with a transition temperature of about 100 °C in solid state, while it gave a reversible LCST transition of 34–36 °C in aqueous solution. The amphiphilic homopolypeptide poly- L -EG 2 -Glu self-assembled into nanostructures in aqueous solution, and their critical aggregation concentrations decreased with increasing MW. Interestingly, their morphology changed from spherical micelles to worm-like micelles, then to fiber micelles with increasing MW. This work provides a simple method for the generation of different nanostructures from a thermosensitive biodegradable homopolypeptide. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
研究领域:
高分子化学
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材料科学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
RUSSIAN JOURNAL OF APPLIED CHEMISTRY
·
2023
·Vol. 95
·期 9
·1489-1496
·
IF 0.9
Li Baixin
Abstract The object of this article was to synthesize a special type of functional polymer material with antimicrobial activity. In this paper, polymer antibacterial materials were synthesized in two steps: (1) acrylamide–cefotiam was synthesized via acrylate chloride reaction with cefotiam at 0–5°C for 8 h；(2) The poly(acrylamide–cefotiam) and poly(acrylamide-co-acrylamide–cefotiam) were synthesized via free radical polymerization method in 60°C using water as the solvent and ammonium persulfate as the initiator. The chemical structure and composition of the acrylamide–cefotiam and obtained polymers were investigated by Fourier transform infrared (FTIR) spectrum and Nuclear magnetic resonance (NMR) spectroscopy. The number-average molecular weight ( M n ) of poly(acrylamide–cefotiam) and poly(acrylamide-co-acrylamide–cefotiam) were determined by gel permeation chromatography (GPC). In order to investigate the effect of the obtained polymers bonding of cefotiam on their antimicrobial properties, the contrast and colony counting were used to investigate the antibacterial properties of polymers against ATCC 8739 E. coli . The polymer bonded to cefotiam has 100% antibacterial properties against ATCC 8739 E. coli . Experimental results provide a new method for preparing antimicrobial polymer materials.
研究领域:
材料科学
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高分子化学
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药学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）