Polymer Chemistry
·
2020
·Vol. 11
·期 18
·3169-3178
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IF 5.342
Chenxi Yu,Huichang Gao,Qingtao Li,Xiaodong Cao
Injectable hydrogels have shown great potential for cartilage tissue engineering as three-dimensional cell culture scaffolds, owing to their similarity to the extracellular matrix (ECM), which endows them with the ability to match irregular defects, minimally invasive properties and convenience for cell transplantation and proliferation. However, injectable hyaluronic acid (HA) hydrogels have limited applications in cartilage tissue engineering due to their poor mechanical properties and fast enzymatic degradation. In this study, a double cross-linked (DC) hydrogel was designed and prepared by combining the Diels–Alder click reaction and a phenyl boronate ester bond, in which the DA reaction provides mechanical properties and the phenyl boronate bond provides versatility, such as injectability, adhesion and anti-degradation. Compared with the single cross-linked hydrogel, the DC hydrogel not only possessed good injectability and pH responsiveness, but also had repeatable strength and durability. In addition, in vitro cell experiments indicated that the injectable DC hydrogel was capable of supporting cell loading and proliferation, thus being a promising candidate for repairing cartilage defects.
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高影响因子
POLYMER
·
2020
·
IF 4.231
Xin-Long Sha,Li Yuan,Guozheng Liang,Aijuan Gu
Preparing high performance shape memory bio-based benzoxazine resin through a green solvent-free strategy is an interesting issue with great challenge. Herein, a green solvent-free strategy is setup to synthesize bio-based benzoxazine monomer ( VFA-atpe ) from amine-terminated polyether and bio-based benzoxazine monomer containing aldehyde group; moreover, cured bio-based benzoxazine resin coded as poly(VFA-atpe) was prepared, of which the integrated performances were studied. Results show that poly(VFA-atpe) not only has high glass transition temperature (280 °C), but also exhibits ultra-high storage modulus (4.2 GPa) and tensile strength (90.4 ± 3.2 MPa), which are much higher than those of all bio-based benzoxazine resins reported so far. In addition, poly(VFA-atpe) shows good shape memory property, its shape recovery efficiency reaches 98%, and thus becomes the first bio-based benzoxazine resin with shape memory ability. These unique integrated performances of poly(VFA-atpe) are attributed to its special structure that simultaneously owns rigid segments and tough polyether.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Yunyan Peng,Yuan Liu,Jinyue Dai,Lijun Cao,Xiaoqing Liu
Sustainable and economically feasible treatment on oily sewage is of great significance. Herein, the benzoxazine monomer (C-fa) derived from renewable feedstock was facilely in-situ polymerized on the skeleton of melamine sponge (MS), accompanied with SiO 2 nanoparticles (NPs). Due to the robust hydrophobicity of poly(C-fa) and the as constructed nano-micro hierarchical structure, the as-fabricated porous composite (PBZ-SiO 2 -MS) showed wide applicability in oily sewage remediation, including selective absorption of layered oil/water mixture, separation of surfactant stabilized W/O and O/W emulsion with ultrahigh separation efficiency (higher than 99.9%) and satisfactory permeation flux (1300 L m −2 h −1 ). In addition, the remarkable flame retardancy of polybenzoxazine and MS, as well as its high absorption speed and capacity, endowed PBZ-SiO 2 -MSs with great ability to confine the flame range and prevent the potential explosion when spilled oil is ignited. This easy fabricated, low cost and versatile PBZ-SiO 2 -MSs illustrated an ingenious example of the integration of the high material performance and green chemistry concept.
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高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2021
·Vol. 61
·期 9
·2257-2266
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IF 2.428
Yunpeng Zhang,Jiaofeng Ye,Dongan Qu,Haitao Wang,Changsheng Chai,Libang Feng
Micro-damage in materials could be repaired by endowing materials with self-healing performance. Herein, an epoxy resin with excellent self-healing performance grounded on thermo-reversible Diels–Alder dynamic chemical reaction was developed. Results showed that the bending strength and adhesive behavior of epoxy resin were influenced dramatically upon treatment with various temperatures. More importantly, damages created in epoxy resin could be repaired completely after suitable heat treatments. What is more, the healed epoxy resin exhibited much higher bending strength and adhesive performance than the pristine one did. The materials could be damaged and then repaired repeatedly. Meanwhile, the as-prepared self-healing epoxy resin exhibited excellent thermal reversibility and controllable adhesion. The thermo-adjusted self-healing performance endowed epoxy resin with recyclable and reusable performance. Therefore, the research made it possible of recycling waste epoxy resins.
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Hafezeh Nabipour,Haoxin Niu,Xin Wang,Sadia Batool,Yuan Hu
There are many applications for epoxy resin as a coating material in the automotive, electronics, and aerospace industries. However, when derived from petrochemical industries, adversely affect the environment, as they are rigid and resistant to recycling due to inherent cross-linked structure. In the present study, we prepared green epoxy resin from renewable resources, able to replace the conventionally produced DGEBA thermoset . Initially, we synthesized an epoxy thermoset from vanillin-derived Schiff base epoxy monomer (VTA-EP) that was thermally cured with bio-based 5, 5′-methylenedifurfurylamine (DFA). Due to the unsaturated double bond in cured VTA-EP/DFA thermoset displayed a relatively high glass transition temperature (T g ~ 170 °C) than the DGEBA/DDM system. Also, tensile strength (60 MPa), storage modulus (3271 MPa), and elongation at break (2.8%) were higher. Additionally, the peak of heat release rate (PHRR) and the total heat release (THR) of the cured VTA-EP/DFA resin decreased, and LOI and UL-94 ratings were improved. The green epoxy thermoset exhibited good dissolution in various acidic conditions due to the degradability of the Schiff base network in contrast to DGEBA/DDM. This work demonstrates that the combination of biomass with Schiff base structure provides a versatile platform for the fabrication of multifunctional vanillin-derived epoxy thermosets.
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高影响因子
EUROPEAN POLYMER JOURNAL
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2021
·
IF 4.598
Yin Lu,Kan Zhang
Two novel fully biobased mono-benzoxazine resins have been designed and synthesized using pterostilbene , furfurylamine/stearylamine and paraformaldehyde via a solventless reaction. The structures of newly obtained mono-benzoxazine monomers have been characterized by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and high-resolution mass spectrometry (HR-MS). The detailed assignments for oxazine-ring protons and carbons in each benzoxazine are identified using 1 H– 13 C heteronuclear multiple quantum coherence spectroscopy (HMQC). Besides, the polymerization processes of benzoxazine resins are studied by differential scanning calorimetry (DSC) and in situ FT-IR spectroscopy, and the thermal stability of their corresponding polybenzoxazines are investigated by thermogravimetric analysis (TGA). Moreover, coatings of both polybenzoxazines on glass slides and low-carbon steels have also been prepared to evaluate their anticorrosion performance. The results indicate that both polybenzoxazines possess good thermal stability and can play efficient roles for shielding corrosion as coatings. Therefore, the current study highlights the utility of the natural renewable pterostilbene as a promising candidate to prepare high-performance bio-based polybenzoxazines.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Jingkai Liu,Yishun Wuliu,Jinyue Dai,Jingyuan Hu,Xiaoqing Liu
Bio-based feedstocks usually contain many isomers with similar structures, and the short alkyl substituents are generally considered as low-reactive groups in benzoxazine chemistry due to their low induction effect and chemical inertness. Therefore, little attention has been paid on their effects on the synthesis or properties of benzoxazine. In this work, two bio-based benzoxazine isomers (CAR-fbz and THY-fbz) containing methyl and isopropyl groups with interchanged positions were synthesized from the renewable carvacrol and thymol. Their synthetic process, crystal features, and curing reactions were carefully investigated. Results showed that different side reacitions and by-products were detected under the same synthese conditions. And using the similar purification method, CAR-fbz and THY-fbz with high purity were found to have different crystal features. In addition, the cured systems also indicated varied H-bonding features and thermal properties based on differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) results. With the help of density functional theory (DFT) calculation, the reasons were attributed to the different electrophilicity of phenol moiety, varied molecular symmetry and intermolecular interaction caused by the overlooked short alkyls. Summarily, the leverage of short-chain alkyl groups on benzoxazine chemistry is revealed. The result is significant for the benzoxazine synthesis, especially when the renewable compounds are taken as the starting materials for bio-based benzoxazine preparation, which often has many isomers with similar structures.
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Wenmei Tan,Wei Shi,Sheng Ding,Zhengfeng Xie
Using renewable substances as the raw materials, and through relatively greener synthetic processes to implement the preparation of novel functional polymers is an idea that accords with the concept of “sustainable development” and is highly desirable in nowadays polymer science. In this study, apigenin (as renewable phenol) and furfurylamine (as renewable amine) were selected to prepare bio-based benzoxazine derivative (AP-f) through Mannich reaction . Using AP-f and diphenylmethane-based diisocyanide (IC) as reactants, a type of cross-linked, semi-aromatic polyamide derivative (Bio-PA) was successfully prepared via benzoxazine-isocyanide mechanochemistry (BIC-MC) by ball milling manner. Chemical structure , elemental composition , micro morphology and stacking state properties of Bio-PA were systematically characterized here. Multiple Pb(II)-affinitive molecular fragments (phenolic hydroxyl , tertiary amine and amide) were integrated into the structure of Bio-PA. Based on this, the application of Bio-PA as “enrichment-type” Pb(II) electrochemical probe was explored subsequently. The results showed that the introduction of Bio-PA significantly improved the response of Pb(II), and the modified electrode (Bio-PA/Nafion/GCE) illustrated satisfactory detection sensitivity and selectivity.
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高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Guofeng Ye,Siqi Huo,Cheng Wang,Qiu Shi,Zhitian Liu,Hao Wang
The synthesis of bio-based high-efficiency flame retardants in accordance with green and facile method is critical yet very challenging for bioplastics, e.g., poly (lactic acid) (PLA). In this study, a bio-based flame retardant named as PF is synthesized by the reaction between phytic acid (PA) and furfurylamine (FA) in water. PF improves the flame retardancy of PLA at low addition. For instance, PLA composite containing only 2 wt% PF passes a UL-94 V-0 classification, and that containing 4 wt% PF exhibits a limiting oxygen index (LOI) of 28.5%, which is 46.2% higher than that of pure PLA. PF slightly reduces the peak heat release rate (PHRR) and total heat release (THR) of PLA in cone calorimeter test (CCT). In detail, 4 wt% PF reduces the PHRR from 362.2 kW/m 2 to 332.7 kW/m 2 by 8%. Additionally, PLA/PF composite is comparable to the neat PLA in terms of mechanical properties and thermal stability when a UL-94 V-0 rating is achieved. The flame-retardant mechanism analyses demonstrate that PF takes action in both gaseous and condensed phases. It is proposed that PF accelerates the generation of melting droplets to take away heat, suppresses the release of combustible gases and improves the compactness of char layer during combustion. This study provides a green and facile strategy to create bio-based high-efficiency flame retardants for the preparation of fire-safe bioplastics holding a promising future in the industry.
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高影响因子
JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 59
·期 18
·2057-2068
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IF 0
Zizhao Qian,Qing Li,Lujie Wang,Feiya Fu,Xiangdong Liu
As a renewable chemical, diphenolic acid (DPA) has attracted immense interest in bio-based polymer science. However, its application for polybenzoxazines is limited due to decarboxylation, that is, the release of CO 2 during the curing reaction of benzoxazine. In this study, the amidation strategy of converting DPA to diphenolic amides (DPAM) was demonstrated to solve this problem while simultaneously improving the thermal properties of polybenzoxazine. DPA was amidated by separately using four amines (hexamine, cyclohexylamine, furfurylamine, and aniline), then reacted with furfurylamine and paraformaldehyde to synthesize their benzoxazine monomers. By using TGA and DMA, all amide-containing polybenzoxazines were found to exhibit excellent thermal stabilities. Among all of the benzoxazine resins, poly(DFA-fa), which was obtained from amidation with furfurylamine, exhibited the highest glass transition temperature ( T g ) of 310°C and a decomposition temperature ( T d10 ) of 406°C. Furthermore, a possible post-curing reaction mechanism was proposed to explain the outstanding thermal performance of poly(DFA-fa) resin. This study proposes an innovative strategy to solve the decarboxylation of DPA-based polymers, which is of significance for high-performance bio-based polymers. Graphical
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RSC Advances
·
2021
·Vol. 11
·期 49
·30943-30954
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IF 3.361
Wei Peng,Yu-xuan Xu,Shi-bin Nie,Wei Yang
Phosphorus-containing flame retardants have received huge interest for improving the flame retardant behavior of epoxy resins (EP) over the past few decades. However, a satisfactory flame retardant effect requires high loading of most phosphorus-containing flame retardants, resulting in the deterioration of the thermo-mechanical properties of the flame retardant epoxy materials. To obtain the flame retardant EP with excellent comprehensive properties, a furfurylamine-derived bis-DOPO derivative (FA-bis-DOPO) was synthesized from bio-mass as a co-curing agent for the flame retardant EP. The incorporation of FA-bis-DOPO improved the mechanical strength, the storage modulus and the glass transition temperature of the flame retardant epoxy materials, owing to its stiffness and reactivity with the epoxy matrix to enhance the crosslinking density. The EP material containing 5.0 wt% of FA-bis-DOPO had an LOI of 31.0% and UL-94 V-0 rating, while the pristine EP had an LOI of 23.5% and failed in the UL-94 test, manifesting the high flame retardant efficiency of FA-bis-DOPO. Besides, the cone calorimeter results demonstrated that the PHRR, THR, and TSP values of the EP/FA-bis-DOPO-5.0 were 28.0%, 27.3%, and 9.9% lower than those of the pristine EP, respectively. The flame retardant mechanism of FA-bis-DOPO could be attributed to the combined vapor and condensed phase mechanisms which involved the interruption of the combustion chain reaction by quenching radicals and the inhibition of the transfer of pyrolytic volatile products by catalytic formation of an intact and compact char layer.
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PubMed
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2021
·
IF 7.664
Yuan Cao,Min Zhi Rong,Ming Qiu Zhang
To tackle the challenge of manufacturing highly filled composite materials via melt compounding and injection molding , the authors proposed a novel approach based on Diels-Alder (DA) chemistry. Polycaprolactone oligomers (PCL olig , M w = 2000 g/mol) were firstly crosslinked by DA bonds, and then the resultant network PCL olig -DA was also connected to maleimide functionalized Al 2 O 3 particles (Al 2 O 3 -M) via DA bonds. Upon being heated to the retro-DA reaction temperature, the covalent adaptable composite network exhibited low viscosity due to de-crosslinking, enabling melt processing and well dispersion of high-concentration fillers. During the subsequent cooling, the composite network was regained because of DA reaction, benefiting increase of the composite’s strength . Consequently, the contradictory requirements for molecular weight of matrix polymer under the circumstances, which had better to be as low as possible during the manufacturing but as high as possible in the ultimate composites, were skillfully satisfied.
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高影响因子
危险品化学品经营许可证（带存储）