POLYMER
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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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产品关联
DOI
高影响因子
POLYMER JOURNAL
·
2019
·Vol. 52
·期 1
·145-152
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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
DESIGNED MONOMERS AND POLYMERS
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2015
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IF 2.78
Nian Deng,Xufeng Ni,Zhiquan Shen
Poly (diethyl vinylphosphonate-co-2-chloroethyl methacrylate) (P(DEVP-co-CEMA)) copolymers are synthesized by free radical copolymerization initiated by benzoyl peroxide. The reactivity ratios for the free radical copolymerization of CEMA (M1) and DEVP (M2) are r1 = 19.45 and r2 = 0.11, respectively. The desired amphiphilic copolymers with relatively low polydispersity index (PDI) and different DEVP contents are isolated and purified from the reaction mixtures through precipitation fractionation. The structures and molecular characteristics of the obtained products are characterized by 1H NMR, FTIR, and SEC analysis. All of these fractionated copolymers have a unimodal distribution and moderate PDI. The thermal properties of the P(DEVP-co-CEMA) copolymers are investigated by TGA and differential scanning calorimetry (DSC) measurements. Single glass transition temperature (Tg) appears in the DSC profiles differing from the existence of two Tgs in the blend of poly (diethyl vinylphosphonate) and poly (2-chloroethyl methacrylate), which indicates the random structure of the copolymers. The MALDI–ToF mass analysis further reveals that DEVP and CEMA units are randomly distributed in the copolymer chains. The self-assembly behavior of the P(DEVP-co-CEMA) copolymers in aqueous solution is preliminarily investigated.
研究领域:
高分子化学
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材料科学
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产品关联
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
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 36
·16107-16118
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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
✓ 已验证
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
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 29
·14997-15002
·
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
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yongpeng Ma,Chaobin Shi,Qinyuan Hong,Jianghui Du,Hongzhong Zhang,Xuanhui Zheng,Zan Qu,Xiaojing Zhang,Haomiao Xu
This study presents the synthesis of a novel sulfur-based copolymer, S-Tha-Cy, through a unique approach involving graft copolymerization and inverse vulcanization, leveraging cyclooctadiene (Cy) as a crosslinking agent and thioacetamide (Tha) as a grafting monomer. The integration of Tha into the copolymer structure enhances sulfur coordination, exposing additional reactive sulfur sites and incorporating nitrogen-containing moieties. These modifications significantly boost the material’s electron-donating ability, promoting the formation of stable coordination covalent bonds with Hg 2+ ions. S-Tha-Cy demonstrates exceptional Hg 2+ removal efficiency, achieving nearly complete (99.99 %) removal within 30 s, even in competitive environments with other heavy metals. Density functional theory (DFT) calculations confirm a high adsorption energy of −0.508 eV for Hg 2+ , indicating a strong affinity of S-Tha-Cy for mercury. Furthermore, the hybrid material S-Tha-Cy-3-N-Al, which combines S-Tha-Cy with nano-Al 2 O 3 , exhibits sustained Hg 2+ removal capabilities from wastewater. This research presents a breakthrough in the design of sulfur-based materials, offering both innovative synthetic strategies and theoretical frameworks for the efficient capture of heavy metals.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Haoze Wang,Huizhe Zheng,Jie Jiang,Ling Zhao,Zhenhao Xi
Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PCTG) is a high-performance engineering copolyester prepared using terephthalic acid (TPA), ethylene glycol (EG), and 1,4-cyclohexanedimethanol (CHDM). In this work, a complex reaction network of PCTG copolyesters involving homopolymerization and cross-polymerization was presented and the corresponding reaction mechanism was proposed. The reaction kinetics and mass transfer behavior were investigated using static thin film experiments, wherein the variation of the hydroxyl end-group concentrations of EG and CHDM with reaction time was separately determined. The results showed that the apparent reaction rate benefited from the high temperature, thin film thickness, and high vacuum conditions. Based on the pseudosteady-state assumption, the apparent reaction rate model coupled with mass transfer was evaluated and the model parameters including the reaction rate coefficient, equilibrium constant, and mass transfer coefficient were obtained, which were further used to simulate the polycondensation process. The concentration variation of EG and CHDM, and the rate variation of each reaction during polycondensation are discussed by combining the effects of homopolymerization, cross-polycondensation, and mass transfer. The concentration of EG was more sensitive to pressure than that of CHDM, which promoted the production of CHDM at high pressures. The proposed model is expected to provide guidance for the optimization of industrial production of PCTG/PETG and generalize to other copolyester systems.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Jianfei Xia,Lingling Ni,Chenxuan Sun,Ying Zheng,Junfeng Liu,Chengtao Yu,Wei Li,Jingdai Wang,Pengju Pan
Copolymerization of diacids and diamines can produce copolyamides with diversified physical properties. Due to the interplay between even–even and odd–even diamine-diacid units, the even–even/odd–even copolyamides can show much different crystal polymorphism and phase transition behavior from the typical (co)polyamides. Herein, we synthesized the novel even–even/odd–even copolyamides from nylon 5,6 and nylon 6,6 salts and investigated their crystallization kinetics, crystalline structure, and phase transition behavior. The copolyamides display the typical isodimorphic behavior, and the solution-crystallized copolyamides experience α–γ Brill transition upon heating. Intriguingly, the crystalline structure and phase transition of copolyamides are strongly influenced by the copolymer composition and initial crystallization temperature (Tc) upon cooling due to the possible change of H-bonding structure regularity induced by the incorporated comonomer units in the crystalline phase. The 66-unit-rich copolyamides initially form the γ phase and subsequently transform into the α phase during cooling, while the 56-unit-rich ones merely crystallize in the γ phase. For the copolyamide with pseudoeutectic composition, high and low Tc promote the generation of single γ phase of PA6,6 and double γ phases of PA5,6 and PA6,6, respectively. Upon cooling, the PA6,6-type γ phase always transforms into the α phase, while the PA5,6-type γ phase is maintained. This study has elucidated the synergetic effects of copolymer composition and Tc on the crystallization and phase transition of isodimorphic copolyamides.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
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
·
药物传递系统
·
生物材料
✓ 已验证
DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Jiaojiao Zhao,Jinling Long,Yongqiang Du,Jiankui Zhou,Yadong Wang,Zipeng Miao,Yingliang Liu,Shengang Xu,Shaokui Cao
Recyclable low-temperature phase change microcapsules (LTPCMs) have the potential applications in the short-distance cold chain transportation due to their reliable reusability in cold storage . Herein, LTPCMs are synthesized via in-situ suspension copolymerization of styrene and methyl methacrylate in absence of harm substances, providing the non-crosslinking copolymer shells. n -Dodecane, n -tridecane and n -tetradecane, inducing the microphase separation of non-crosslinking copolymers, are successfully encapsulated to achieve n -do-LTPCMs, n -tri-LTPCMs and n -tetra-LTPCMs, which respectively bear the high phase change enthalpy of 110.53 J·g −1 at −8.69 °C, 38.33 J·g −1 /93.71 J·g −1 at −17.61 °C/−4.96 °C and 166.79 J·g −1 at 8.59 °C and subsequently show the cold-discharging periods of 30 min, 40 min and 120 min. The multiple circulation of cold-discharging process indicates the excellent recyclability for cold storage owing to their unchanged cold-discharging period. Especially, n -tetra-LTPCM-65 bears the best comprehensive cold-storing performance in all the previously reported LTPCMs, such as narrow cold-discharging temperature range of 3–4 °C, long cold-discharging period of 69–120 min and low cold-discharging capacity of 33.4 J·g −1 ·K −1 . This work successfully provided the recyclable LTPCMs for cold storage in the short-distance cold chain transportation.
研究领域:
材料科学
·
能源存储
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）