POLYMER
·
2019
·
IF 3.771
Longfei Li,Hong Zhai,Tao Wang,Xibo Qiu,Na Qiang,Peng Dong,Ying Bai,Ai-Yun Peng,Daping Quan
The ring-opening copolymerization of lactide with carbonate is an available strategy to incorporate reactive groups to the pendent sites of copolymer for further functional modification. A series of random and block copolymers were synthesized from l -lactide ( L -LA) and 2-bromomethyl-2-methyltrimethylene carbonate (BMTC) using dodecanol as initiator and stannous octoate as catalyst. The structures of the copolymers were characterized by nuclear magnetic resonance ( 1 H NMR, 13 C NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The composition of the copolymers can be controlled through changing the feed ratios of n BMTC / n L -LA . It was found the random P(BMTC- co - L LA) copolymers had the semicrystalline characteristic due to the relative long block-like segments of P L LA ( L L , P L LA = 5.3–7.3) and the polar interactions from bromo groups , but their crystallinity ( X c, P L LA ) and melting temperature ( T m, P L LA ) decreased when the BMTC content increased. The X c, P L LA and T m, P L LA of P(BMTC- b -P L LA) block copolymers were relatively higher than the corresponding random copolymers, and approached gradually to the pure P L LA with the increase of the molecular weight of P L LA block. Finally, the pendent bromo groups of P(BMTC- co - L LA) were easily transformed into azides , which could proceed the azide-alkyne click reaction smoothly and quantitatively at room temperature .
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 46
·40371-40382
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IF 3.289
Xuefei Leng,Zhiyong Wei,Yingying Ren,Yufei Bian,Qinyi Wang,Yang Li
A series of linear-comb poly(trimethylene carbonate)-block-poly(L-lactide) [lcP(TMC-b-LLA)] with polybutadiene (PB) as backbone and a P(TMC-b-LLA) diblock copolymer as side chain were obtained using controlled synthesis and evaluated as thermoplastic elastomers. The comb-like graft copolymer was achieved using sequential ring-opening polymerization of trimethylene carbonate (TMC) and L-lactide (L-LA) at room temperature (RT) using an organocatalyst, associated with the multi-hydroxyl PB (PB–OH) as a macroinitiator. The thermal and mechanical properties of these graft copolymers were investigated using differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The Young's modulus (E) and the elongation at break (εb) followed predicted trends as the monomer composition changed. Furthermore, well defined linear-comb PLLA-gradient-PTMC [lcP(LLA-grad-TMC)] and linear-comb PLLA-random-PTMC [lcP(LLA-ran-TMC)] were also synthesized for comparison. Results from 1H and 13C-NMR spectroscopy, and gel permeation chromatography confirmed the formation of the chain microstructures. It was found that the properties of the copolymers depended not only on the comonomer content but also on their topologies. The results showed that the gradient and random structure of the side chain could yield unusual properties: the lcP(LLA-grad-TMC) copolymer possessed a distinctive, broad glass transition temperature in comparison with the other two graft copolymers. The lcP(LLA-ran-TMC) random copolymer performed like a typical rubber with a significant high εb value (εb = 1800%) which was even larger than the pure linear-comb PTMC (εb = 865%). Furthermore, this simple “one-pot” method using an organocatalyst to synthesize comb-like graft copolymers with “block”, “gradient” and “random” side chains is demonstrated systematically in this work.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 36
·16107-16118
·
IF 2.7
Zhoufeng Wang,Bolin Wang,Yingying Liu,Xiubo Long,Wenlong Yao
A series of linear block polymers and random polymers were synthesized by interfacial polycondensation using two bisphenols with similar structures, bisphenol S (BPS) and bisphenol A (BPA), and terephthaloyl chloride and isophthaloyl chloride. Random polymers and block polymers with the expected topology were structurally characterized by 1H NMR, FTIR, GPC, WAXD, and Raman spectroscopy. The results demonstrated that there was no significant difference in the thermal stability of the block and random polyarylates, which was due to the fact that the covalent bonds of the linked monomers did not change substantially, and the bond energies were the same. However, due to the alteration of the molecular sequence structure, the block polymer exhibited a lower glass transition temperature, a pronounced melting peak, and better solubility. With physical cross-linking points consisting of microcrystalline phases formed by the relatively regular molecular chain structure, the block polyarylates exhibited a higher modulus of elasticity than the random polyarylates. This illustrated that it is possible to prepare new functional polyarylates without changing the monomer composition, but only by manipulating the reaction process.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
Frontiers in Pharmacology
·
2022
·
IF 5.988
Huang Jianbo,Wang Hong,Huang Lei,Zhou Yuqing
Background: Lipid and polymer microbubbles (MBs) are widely used as ultrasound contrast agents in clinical diagnosis, and possess great potential in ultrasound-mediated therapy due to their drug loading function. However, overcoming the limitations of stability and echo enhancement of MBs are still a considerable challenge.Methods: A series novel block, graft and block-graft copolymers was proposed and prepared in this work, and these copolymers were used as shells to encapsulate perfluoropentane as ultrasound contrast agents. First, block, graft and block-graft copolymers with different topological structures were prepared. Then, these copolymers were prepared into block copolymer phase-transition MBs, graft copolymer phase-transition MBs, and block-graft copolymer phase-transition MBs, respectively. Finally, the dexamethasone was used for drug-loaded phase-transition microbubbles model to explore the potential of theranostic microbubbles.Results: Finally, these three resulting copolymer MBs with average size of 4–5 μm exhibited well enhancement of ultrasound imaging under the influence of different frequencies and mechanical index, and they exhibited a longer contrast-enhanced ultrasound imaging time and higher resistance to mechanical index compared with SonoVue in vitro and in vivo. In vitro drug release results also showed that these copolymer MBs could encapsulate dexamethasone drugs, and the drug release could be enhanced by ultrasonic triggering. These copolymer MBs were therapeutic MBs for targeted triggering drug release.Conclusion: Therefore, the feasibility of block, graft, and block-graft copolymers as ultrasonic contrast agents was verified, and their ultrasonic enhancement performance in vitro and in vivo was compared. The ultrasound contrast agents developed in this work have excellent development potential in comprehensive diagnosis and treatment.
研究领域:
材料科学
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生物医学工程
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超声成像
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药物递送系统
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 29
·14997-15002
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IF 3.708
Tian Lan,Wenjie Yang,Hao Huang,Yinghan Wang
Response time, an important property of polymer dispersed liquid crystals (PDLCs), was reported to be affected by the structures of the polymer matrix. In this study, reversible addition fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP) were used to synthesize a well-defined copolymer matrix. A kind of graft macroinitiator with both controlled main chain and branched chains was employed to prepare PDLCs with a graft copolymer matrix; meanwhile a linear macroinitiator was also synthesized to prepare PDLCs with a linear copolymer matrix. The effect of different matrix structures on response times was investigated. It was found that the introduction of branched chains made a big difference to response times, and a possible mechanism was proposed.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
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2020
·
IF 0
Xuan Wang,Fanfan Li,Huanhuan Zhao,Yanwu Zhang
In order to improve the sustained release properties of carriers and explore the effect of copolymer sequence structures on sustained release, 5 groups of 12 block copolymers (12-BCPs) with different sequences were prepared using 4 monomers and the microstructure was controlled by changing the sequence of monomers. The results show that each polymer chain contains an average of 228 monomers and the proportion of 4 monomers basically conforms to 1:1:1:1. The release kinetics of fluorescein sodium (FS) as a drug model molecule was detected by UV–vis spectroscopy, and the result proves that sequence microstructures have great effect on their sustained release behaviors. The five groups of copolymers all show high initial loading (49.6–74.6 mg/g) and long sustained release time (18–30 days). The copolymer with the largest monodisperse self-assembly size (13.40 μm) in which the block sequence is 2-hydroxyethyl acrylate/styrene/4-vinylpyridine/tert-butyl acrylate has the optimal drug loading capacity (74.6 mg/g) compared with others. At the same time, it owns the most stable release state and the longest sustained release time (30 days).
研究领域:
高分子化学
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药物传递系统
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生物材料
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DOI
MACROMOLECULAR CHEMISTRY AND PHYSICS
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2019
·Vol. 220
·期 22
·1900349
·
IF 2.622
Lan Ding,Pengfei Zhang,Congcong Fu,Jialin Yin,Yongwang Mao,Na Liu,Shihua Li,Chunying Yang,Ronghui Zhao,Kuilin Deng
Two thermosensitive copolymers of acrylates (PMP/PEP) and a thermo/light sensitive copolymer of acrylate with acrylamide (PMABz) are synthesized via a ring-opening reaction and subsequent radical polymerization using a facile one-pot method. The lower critical solution temperature (LCST) of PMP and PEP shows a dependence on the content of the structural unit and can be easily tuned to 18–35 °C by mercaptoethanol-mediated control of the molecular weight. The isomerization of PMABz can be reversibly induced by alternating irradiation at 365 nm to produce the cis form and at 254 nm to produce the trans form. The LCST of cis -PMABz (40.3 °C) is significantly higher than that of trans -PMABz (37.8 °C) because of its higher hydrophilicity. Furthermore, the particle size of aggregated PMABz can be controlled from 665 nm (for the cis form) to 996 nm (for the trans form) during the heating run. After quenching the PMABz solution, PMABz particles have repeating patterns, such as leaf veins or hollow containers, indicating their potential applicability.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
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2021
·Vol. 42
·期 17
·2100298
·
IF 5.734
Gui-Ying Kang,Wei Ma,Ming-Zhu Liu,Hai-Xi Luo,Cui-Yun Yu,Hua Wei
8-Shaped copolymers with two macrocycles connected together represent an interesting cyclic topology-derived polymer species due to the simultaneous incorporation of two cyclic moieties and the reported unique physical and chemical properties. To provide a proof-of-concept for a broad readership on biomedical polymers, a well-defined hetero-8-shaped amphiphilic copolymer, cyclic-poly(oligo(ethylene glycol)monomethyl ether methacrylate)- b -cyclic PCL ( c POEGMA- b - c PCL) is synthesized by an elegant integration of intrachain click cyclization and interchain click coupling. The potential of the self-assembled micelles of c POEGMA- b - c PCL for controlled drug release is evaluated by in vitro drug loading and drug release, cellular uptake, cytotoxicity, and degradation studies. Most importantly, the micelles based on c POEGMA- b - c PCL show much slower degradation profiles than the previously reported linear counterpart, POEGMA- b -PCL and tadpole-shaped analog, PEG- b - c PCL because of the presence of cyclic hydrophilic POEGMA segment. Therefore, this study not only develops a robust strategy for a universal precise synthesis of well-defined hetero-8-shaped copolymers based on diverse vinyl and ring-structured monomers, but also reveals the first modulation of polymer degradation property by topological control of the nondegradable moiety in the polymer construct through advanced macromolecular engineering.
研究领域:
高分子化学
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生物材料
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药物递送系统
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DOI
PubMed
高影响因子
JOURNAL OF FLUORINE CHEMISTRY
·
2021
·
IF 2.05
Nianze Song,Xin Huang,Yifei Li,Kaokao Zhang,Chaihui Wei,Jian Zhang,Yue Zhang
ABSTRACT To deal with the demulsification of emulsion stabilized by naphthenic compounds, a series of multibranched–linear–multibranched (MLM) copolymer were designed and synthesized. The hydrophilic core with MLM structure is constructed by anionic ring-opening multibranching polymerization (ROMBP) of glycidol with poly (ethylene glycol). The amphophobic arms are grafted by atom transfer radical polymerization (ATRP) of 2, 2, 2-trifluoroethyl methacrylate (TFEMA). The demulsification performance of the MLM copolymer in n-octane/water emulsion stabilized by naphthenic acids (NAs) and sodium naphthenates (Na-NAs) were evaluated. The influences of copolymer dosage, temperature and Na-NAs/NAs ratio on the demulsification efficiency were investigated in detail. Compared with the blank sample settled for 90 min, the fluorinated MLM copolymer with medium HLB value promoted the demulsification efficiency from 50% to 92%. By analyzing the correlation between the polymer structure and demulsification performance, it can be considered that the PEG segment improved the low solubility of the fluorinated copolymer caused by the solvophobic nature of fluorinated groups. The amphophobic effect of the fluorinated group not only accelerates the diffusion process of polymer molecules from the bulk to the interface, but also reduces the rigidity of the interface film by repelling the original interface active material, and produces effective demulsification.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
POLYMER JOURNAL
·
2019
·Vol. 52
·期 1
·145-152
·
IF 2.639
Bai Hongyuan,Han Li,Ma Hongwei,Yang Lincan,Li Chao,Liu Pibo,Shen Heyu,Lei Lan,Zhang Songbo
A sulfur-containing styrene derivative, 4-methylenethiochromane (META), was subjected to anionic copolymerization with isoprene (Ip) modified with different additives. The reactivity of META can be effectively regulated with additives; thus, gradient and alternating copolymers were prepared in a facile manner. When THF and TMEDA were utilized in the copolymerization, the reactivity was better than that observed without additives, and thus, gradient copolymers with different gradient extents can be synthesized. In addition, metal alkoxides (such as sodium 2,3-dimethylpentan-3-olate (NaODP) and potassium tert -butoxide ( t -BuOK)) were better able to regulate the reactivity, and the copolymers exhibited alternating and nearly alternating sequences. Therefore, the regulation of the alternating or gradient copolymerization of META and Ip was facilely realized through the use of additives.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
Collagen and Leather
·
2024
·Vol. 6
·期 1
·1-12
·
IF 0
Yi Yudan,Fan Xinxin,Li Qijun,Wang Ya-nan
Hydrophobicity enhancement of metal-free leather, which is crucial for improving its comprehensive performance, can be achieved by using amphiphilic copolymer retanning agents. However, the relationship between the sequential structure and the hydrophobic modification effect of amphiphilic copolymers remains unclear. Herein, an amphiphilic block copolymer was synthesized using stearyl methacrylate and 2-(dimethylamino)ethyl methacrylate via atom transfer radical polymerization, and the corresponding random copolymer with similar monomer compositions and molecular weights was prepared for comparison. The aggregation behavior of block and random copolymers was investigated. DLS and TEM results indicate that the block copolymer exhibits a larger aggregate size than the corresponding random copolymer. Molecular dynamics simulations suggest that the block copolymer aggregate exhibit a thicker hydrophilic shell and more concentrated distribution of cationic DMA block than the random copolymer aggregate. Subsequently, the block and random copolymers were used for the hydrophobic modification of metal-free tanned collagen fibers (CFs). The block copolymer shows superior binding capacity to CFs than the random one because of its larger size and more concentrated charge distribution. Hence, the block copolymer can form a dense and uniform hydrophobic film on the surface of collagen fibrils and endow CFs with higher hydrophobicity than the random one. This work provides theoretical guidance for modulating the hydrophobicity of CFs by tailoring the sequential structure of amphiphilic copolymers, which is expected to inspire the manufacturing of high-performance metal-free leather. Graphical Abstract
研究领域:
材料科学
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高分子化学
·
表面工程
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DOI
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Wenyuan Xie,Chenguang Jiang,Xing Yu,Xinyu Shi,Shubin Wang,Yu Sun,Ming Yin,Defeng Wu
Biodegradable polymersomes that can potentially be employed in drug delivery systems were fabricated by blending poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide) (PLLA-PEG-PLLA) and poly(d-lactide)-b-poly(ethylene glycol)-b-poly(d-lactide) (PDLA-PEG-PDLA) block copolymers in a weight ratio of 1:1 in an aqueous solution. A series of amphiphilic PLLA-PEG-PLLA and PDLA-PEG-PDLA triblock copolymers were synthesized with different hydrophobic chain lengths through ring-opening polymerization. The self-assembly of pure PLLA-PEG-PLLA and an equimolar mixture of enantiomers of PLLA-PEG-PLLA and PDLA-PEG-PDLA was investigated by transmission electron microscopy, X-ray diffraction, and dynamic light scattering. Various nanostructures including spherical micelles, worm-like micelles, and vesicles were obtained by controlling the hydrophobic chain length and the incubation temperature. In the pure PLLA-PEG-PLLA systems, the hydrophobic–hydrophilic balance dominated the self-assembled morphologies. In equimolar enantiomer mixtures, self-assembled morphologies were greatly affected by the formation of the PLLA-PDLA stereocomplex (SC). There was an inverse correlation between the SC crystallinity and the curvature of the self-assembled structures─the higher the SC content, the smaller the curvature. This rule was not applicable when the SC content was too high (≳50%), which produced spherical micelles as the main nanostructures. Since the SC-induced self-assembly could be controlled by changing the incubation temperature, the polymersomes can potentially be used in many applications, such as nanoreactors and nanovehicles.
研究领域:
材料科学
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药物递送系统
·
高分子化学
✓ 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）