EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Xi Chen,Xiaojun Liu,Congcong Miao,Pengfei Song,Yubing Xiong
Inimer bears a polymerizable vinyl group and a reactable group, and thus has great potentials in the synthesis of branched and functional polymers. Herein, a strategy was developed for the synthesis of ionic liquid (IL)-like inimer containing a trithiocarbonate moiety and a styryl group. The newly-developed IL-like inimer could be facilely achieved via the neutralization reaction using a carboxyl-contained chain transfer agent (CTA) and an alkaline IL monomer. The IL-like inimer was characterized through proton and carbon nuclear magnetic resonance spectroscopy ( 1 H and 13 C NMR), Flourier transform infrared spectroscopy (FT-IR) and Mass spectroscopy. Moreover, the reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAM) mediated by the as-prepared IL-like inimer was investigated. The results revealed that branched PNIPAM with tunable molecular weight and degree of branching (DB) could be prepared. Additionally, lower critical solution temperature (LCST) of branched PNIPAM could be adjusted through the feed ratio of IL-like inimer and the monomer in the polymerization process. As a result, our study offers a new technique for the design of functional inimer, as well as broadens the application of ILs in the polymer field.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH INNOVATIONS
·
2025
·
IF 0
Pingli Dai,Di Zhu,Li Jiang,Qimin Jiang,Hongjun Yang,Wenyan Huang,Xiaoqiang Xue,Bibiao Jiang
This paper takes poly2-hydroxyethyl methacrylate (PHEMA) as an example, the effects of linear and branched structures on the microrheological properties of polymers are studied to further supplement and further understand the importance of microrheological properties for optimising material properties and expanding the scope of application. The experimental results show that the higher the molecular weight of linear PHEMA, the higher the storage modulus and the higher the complex viscosity; the higher the degree of branching of branched PHEMA, the lower the storage modulus and the lower the complex viscosity. The mean square displacement of tracer particles in isopropanol solutions of linear and branched PHEMA has a good linear relationship with the lag time, and the slope of the curve of linear PHEMA(0.74 ~ 0.86) is smaller than that of branched PHEMA(0.91 ~ 0.95). The loss factor of linear PHEMA is lower than that of branched PHEMA.
研究领域:
材料科学
·
高分子化学
·
流变学
✓ 已验证
产品关联
DOI
MATERIALS RESEARCH INNOVATIONS
·
2025
·
IF 0
Yu Tian,Feiyao Huang,Di Zhu,Li Jiang,Qimin Jiang,Hongjun Yang,Wenyan Huang,Xiaoqiang Xue,Bibiao Jiang
The branched poly (2-hydroxyethyl methacrylate)(BPHEMA) was carried out using 2-methyl-n-[3-(methyl phenyl amino)-propyl]–acrylamide(MPAEMA, synthesised in laboratory) and benzoyl peroxide(BPO) as redox initiator by water/toluene inverse emulsion polymerisation. The weight-average molecular weight (Mw.MALLS), mean-square radius of gyration(Rg), intrinsic viscosity([η]), relative branching factor g and g’, and micro rheological properties of BPHEMA were measured by static and dynamic light scattering(DLS-SLS) and Ubbelohde viscometer. The results show that the BPHEMA was synthesised by inverse emulsion polymerisation at room temperature. The degree of branching increased with the increase of the content of reducing agent MPAEMA in the feed ratio, and the molecular weight was not affected significantly by the change of feed ratio. However, the molecular weight of linear poly (2-hydroxyethyl methacrylate) (LPHEMA) was significantly affected by the change of feed ratio.
研究领域:
高分子化学
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材料科学
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物理化学
✓ 已验证
产品关联
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Yong Yang,Qingliang Meng,Zhenghong Guo,Juan Li,Zhengping Fang
A series of bio-based 2,5-thiophenedicarboxylates were successfully synthesized, and their chemical structures were characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The influence of alkyl chain length and branching on the plasticizing properties of 2,5-thiophenedicarboxylates in poly(vinyl chloride) (PVC) was evaluated through dynamic mechanical analysis (DMA), hardness measurements, and tensile testing. It was found that the plasticizing efficiency of 2,5-thiophenedicarboxylates decreased as the alkyl chain length increased, as reflected by the gradual increase in glass transition temperature ( T g ), hardness, and elastic modulus. Additionally, among 2,5-thiophenedicarboxylate isomers with the same molecular weight, those with branched alkyl chains exhibited superior plasticizing efficiency compared to those with linear alkyl chains. The above results suggested that optimizing alkyl chain length and branching could further improve the plasticizing efficiency of 2,5-thiophenedicarboxylate plasticizers in PVC. Notably, 2,5-thiophenedicarboxylates showed greater polarity and improved migration resistance in non-polar solvents than commercial dioctyl phthalate (DOP), suggesting their potential application in PVC products exposed to non-polar environments.
研究领域:
高分子材料
·
塑料加工
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增塑剂化学
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聚合物物理
·
生物基材料
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 29
·4717-4727
·
IF 5.687
Qingfu Ban,Jie Kong
Well-defined hyperbranched polymers with long-chain backbones between the branched points (HyperMacs) are an emerging issue in topological polymers. Owing to the difficult discrimination of branching points interfered with or overlapped by long-chain backbones in nuclear magnetic resonance signals, the fine identification and quantitative characterization of intramolecular cyclization and the calculation of the degree of branching for HyperMacs are always challenges. In this contribution, a convenient expression of the macro-cyclic index (m-CI) was presented and deduced as the ratio of NA/NB of HyperMacs to that of their completely intramolecular cyclized analogues. The physical meaning of m-CI is the similarity of HyperMacs to their completely cyclized analogues. Accordingly, a m-CI closer to 1 means a high degree of intramolecular cyclization, even complete cyclization. The experimental validation via model polymers indicates that m-CI is a facile parameter to analyze intramolecular cyclization of HyperMacs. The increase of the chain length of the backbones between branched points can enhance intramolecular cyclization of HyperMacs accompanied with the increase of the m-CI value. As an original contribution to polymer science, the presentation of m-CI overcomes the difficult problem of quantitative characterization of intramolecular cyclization in long-chain hyperbranched polymers, which is helpful for a good understanding of their relationship between topological structures and properties.
研究领域:
高分子科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
MOLECULES
·
2022
·Vol. 28
·期 1
·46
·
IF 4.927
Huaizhi Pan,Biao Zheng,Hui Yang,Yingying Guan,Liuyang Zhang,Xiaoli Xu,Aimin Wu,Huiling Li
Hemicellulose is the second most abundant natural polysaccharide and a promising feedstock for biomaterial synthesis. In the present study, the hemicellulose of loblolly pine was obtained by the alkali extraction-graded ethanol precipitation technique, and the hemicellulose-polyvinyl alcohol (hemicellulose-PVA) composite film was prepared by film casting from water. Results showed that hemicellulose with a low degree of substitution is prone to self-aggregation during film formation, while hemicellulose with high branching has better compatibility with PVA and is easier to form a homogeneous composite film. In addition, the higher molecular weight of hemicellulose facilitates the preparation of hemicellulose-PVA composite film with better mechanical properties. More residual lignin in hemicellulose results in the better UV shielding ability of the composite film. This study provides essential support for the efficient and rational utilization of hemicellulose.Keywords:loblolly pine;hemicellulose;graded ethanol precipitation;hemicellulose-polyvinyl alcohol composite film
研究领域:
材料科学
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生物材料
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林业
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2020
·
IF 4.231
Wei-Guang Chen,Nan Hu,Yu Chen,Hong Pan
Multifunctional branched polylactides (BPLAs) with N,N -bis(2-hydroxyethyl)glycine (BHEG) as branching units were prepared. The as-prepared BPLAs had degree of branching in the range of 5.7–9.1%, number-average molecular weight in the range of 7.4 kDa–9.3 kDa, and dispersity in the range of 1.3–1.7. The tertiary amine groups of BHEG units endowed BPLAs intrinsic photoluminescence (PL) nature with quantum yield (QY) in the range of 1.2–2.0% under the maximum excitation wavelength of 360–370 nm and the maximum emission wavelength of 439–445 nm. Oxidized BPLAs showed the maximum excitation wavelength of ca. 473 nm as well as the maximum emission wavelength of ca. 540 nm, and much higher QYs of 9.1–10.5%. The tertiary amine groups of BHEG units also endowed BPLAs guest-encapsulation capacity. The obtained BPLAs were effective multifunctional additives for poly( l -lactide) plastics, embodied with improved crystallization and mechanical properties , PL property and new functions through hosting functional guest molecules.
研究领域:
高分子科学
·
材料科学
·
化学
·
生物医学工程
✓ 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）