CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Yujie Sun,Qiongen Hu,Jiangtao Qian,Ting Li,Piming Ma,Dongjian Shi,Weifu Dong,Mingqing Chen
Based on stearyl chloride and native starch, esterified starch were prepared and the chemical structure was characterized by 1 H NMR and FTIR. It was found that stearyl chloride was an efficient agent to fabricate esterified starch with high degree of substitution (DS). During the melt blending of esterified starch (80 wt%) and poly(caprolactone) (PCL, 20 wt%), it was shown the torque of PCL/esterified starch was much lower than that of PCL/native starch without any plasticizer, and further decreased with increasing DS. Compared with PCL/native starch, the tensile properties of PCL/esterified starch composites were significantly enhanced. The tensile strength and elongation at break were increased from 2.7 MPa to 56% for PCL/native starch composites to 9.1 MPa and 626% for PCL/esterified starch ones with DS of 1.50, respectively. SEM observation revealed the esterified starch particles in matrix became smaller and more uniform. In addition, the water resistance and hydrophobic character of PCL/esterified starch composites were improved. PCL composites containing 80 wt% esterified starch with favorable mechanical properties would have great potential applications in broad areas.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2022
·
IF 7.758
Jianqiang Sun,Haofeng Zhu,Xindong Yang,Yan Zheng,Tianchi Sun,Honglei Xu,Jiaqi Meng,Anping Zhang
Phthalate esters (PAEs) are ubiquitous in agricultural soil and crops because of the widespread application of plastic films containing PAEs. The enzymes play critical roles in the elimination of pollutants from environmental matrices. In an attempt to evaluate the effect of enzymes on the degradation of various PAEs, this study investigated the enzyme-catalyzed reaction kinetics of seven selected PAE congeners in water and soil. Carboxylesterase and lipase catalyzed the transformation of PAEs to monoalkyl phthalate esters and phthalic acid with the half-life ranges of 4.78–126.03 h. PAEs with long-alkyl-chain were more recalcitrant to carboxylesterase and lipase-catalyzed degradation, and PAEs with short alkyl chains were relatively easier to be degraded by the two enzymes. The results indicate that the alkyl chain length had a profound effect on the enzyme-catalyzed degradation of PAEs. The reaction rates and half-lives were significantly correlated with the log Kow value ( p < 0.01), which was dominated by the molecular structure. The results obtained in this work are expected to well guide the application of carboxylesterase and lipase in the remediation of waterbody contaminated by various PAEs. With respect to soil, they can be well used in the remediation, exposure, and risk assessment of paddy soil. However, the application of the results in the remediation of other soils might lead to the risk of a low removal ratio.
研究领域:
环境科学
·
生物化学
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Jinbao Xu,Weiguo Liang,Jie Zhang,Zhixian Dong,Caihong Lei
Side-chain functionalized poly( ε -caprolactone) (PCL) is of much ongoing interest in light of its biocompatible and biodegradable features being widely applied in the field of biomaterials, but the versatile and robust protocols for the preparation of PCL-based (co)polymers with functional pendants remaining a challenge. Herein, an organic base of tetramethylguanidine (TMG) promoted esterification reaction of a variety of carboxylic acids and a -Cl of poly( α -chloro- ε -caprolactone) (P( α- Cl - CL)), enabling the direct synthesis of side-chain functional PCL, is described with wide substrate scope in mild reaction condition. It is noteworthy that this protocol affords one versatile and robust method for the preparation of PCL-based functional polymers, which are of high attraction for their application in biological area.
研究领域:
生物材料
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Jiexiang Tong,Subin Xie,Jia-Tao Miao,Jing Luo,Ren Liu
Polyurethane-urea acrylate (PUUA) has been used to develop mechanically robust materials, due to the urea-based bifurcated H-bond. However, the uncontrollable reaction rate between diamine and diisocyanate makes it difficult to prepare PUUA. Herein, we put forward a simple method to synthesize PUUA, which was then used to prepare UV-cured PUUA coatings with simultaneous high hardness and excellent toughness. In our strategy, a novel diol containing urea group has been designed, which was employed as chain extender to synthesize PUUA at a controllable polymerization rate. By adopting chain extenders with different molecular structures, two kinds of PUUA were synthesized. The molecular structures of diol containing urea group and PUUA were identified by Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance spectroscopy ( 1 H NMR). Benefiting from the strong urea-based H-bond, the UV-cured PUUA films showed simultaneously enhanced mechanical strength and toughness. Specially, the optimal PUUA film exhibited high mechanical strength (19 MPa), high elongation at break (310 %), and high toughness (26.9 MJ m −3 ), which was 9.5, 2.8 and 19.2-fold increase compared with polyurethane acrylate (PUA) film without urea groups. Correspondingly, the UV-cured PUUA coatings exhibited higher impact resistance and higher hardness than PUA coating. This work provides a new avenue to develop PUUA for high-performance UV-curable coatings.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 34
·4331-4337
·
IF 3.1
Xin Xiao,Wenchun Liao,Rao Ma,Long Huang,Yunhui Yang
In this work, a highly sensitive colorimetric sensing platform was designed for the detection of trichlorfon based on inhibiting thiocholine (TCh)-induced redox reaction. 5,10,15,20-Tetracarboxyphenylporphyrin (TCPP) functionalized CuCo2O4 (TCPP–CuCo2O4) was synthesized to construct a colorimetric sensing platform for trichlorfon. In the presence of H2O2, TCPP–CuCo2O4 can oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue ox-TMB, accompanied by a strong absorption peak at 652 nm, while acetylcholinesterase (AChE) can specifically hydrolyze acetylthiocholine (ATCh) into TCh, which can reduce ox-TMB back into colorless TMB, resulting in a lower absorbance at 652 nm. Trichlorfon can irreversibly inhibit the activity of AChE and thus recover the absorption peak. Under the optimized conditions, detection of trichlorfon has a wide linear range of 40–4000 ng mL−1 with a linear correlation coefficient of 0.9904. The proposed method can be applied to the detection of trichlorfon in vegetables and has good application prospects.
研究领域:
分析化学
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环境科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 7
·1759
·
IF 5
Yuxian Ma,Minghui Zhang,Wenhao Du,Shixiong Sun,Benbo Zhao,Yuan Cheng
Waterborne coatings have obtained more and more attention from researchers with increasing concerns in environmental protection, and have the advantages of being green, environmentally friendly and safe. However, the introduction of hydrophilic groups leads to lower hydrophobicity and it is difficult to meet the requirements of complex application environments. Herein, we proposed an optimization approach of waterborne polyurethane (WPU) with vinyl tris(β-methoxyethoxy) silane (A172), and it was found that the surface roughness, mechanical properties, thermal stability and water resistance of WPU will be increased to a certain extent with the addition of A172. Moreover, the hydrophobicity of the coating film is best when the silicon content is 10% of the acrylic monomer mass and the water contact angle reaches 100°, which could exceed two-thirds of the research results in the last decade. Therefore, our study can provide some theoretical basis for the research of hydrophobic polyurethane coatings.Keywords:silane coupling agent;waterborne polyurethane;acrylate;hydrophobic modification
研究领域:
材料科学
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高分子化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2023
·Vol. 52
·期 9
·1048-1065
·
IF 1.2
Li Dan,Zheng Yingdi,Jin Yang,Li Yixin
The fundamental physical properties including density, viscosity and refractive index have been measured for binary mixtures of four fatty acid ethyl esters mixed with diethyl carbonate (DEC) over the entire composition range at temperatures T = (293.15 to 323.15) K and normal atmospheric pressure. The values of excess molar volume, viscosity deviation and refractive index deviation are calculated and the effects of temperature and composition on the variation of excess properties are discussed. All of the values of excess molar volume and refractive index deviation are observed to be positive and the values of viscosity deviation are negative. The excess or deviation properties have also been evaluated and fitted to the Redlich–Kister equation with satisfied results.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 29
·e55670
·
IF 2.7
Jinyun Cui,Huaping Wang,Xinyi Chen,Ze Kan,Zhibo Li
Poly(butylene-adipate-co-terephthalate) (PBAT) is recognized for its advantages as a biodegradable thermoplastic polyester. However, its application is often limited due to low strength and poor processability. In contrast, poly(4-hydroxybutyrate) (P4HB) emerges as a fully biodegradable polyester characterized by high strength, excellent toughness, and facile processing. In this study, P4HB was employed to reinforce PBAT, and glycidyl methacrylate grafted onto poly(4-hydroxybutyrate) (P4HB-g-GMA) was introduced as an effective compatibilizer to address their inherent incompatibility. The study explored the influence of P4HB-g-GMA content on the mechanical, thermal, morphological, and rheological properties of the blends. The findings revealed that P4HB-g-GMA significantly enhanced the compatibility, mechanical properties, and melt strength of PBAT/P4HB blends. Furthermore, various PBAT/P4HB foams were prepared through a batch foaming process, employing supercritical CO 2 as a physical foaming agent. The volume expansion ratio and cell size of PBAT/P4HB foams increased with higher levels of the compatibilizer.
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
CHEMOSPHERE
·
2023
·
IF 8.8
Yan-Yan Liu,Yi-Xin Zhang,Hua-Mei Wen,Xiao-Long Liu,Xin-Jiong Fan
Phthalate esters (PAEs) and parabens are environmental pollutants that can be toxic to human health. Herein, a cold-adapted esterase from the Mao-tofu metagenome named Est1260 was screened for its PAE-hydrolyzing potential in cold temperatures. The results showed that purified Est1260 could degrade a variety of PAEs and parabens at temperatures as low as 0 °C. After careful analysis of the structural information and molecular docking, site-saturation mutation was conducted at the identified hotspots. Protein expression of variant A1B6 doubled, and its thermal stability significantly improved (24 times) without sacrificing activity at low temperatures. In addition, Est1260 and its variants were activated by NaCl and demonstrated resistance to high concentrations of saline (up to 5 M), making it a potential biocatalyst for bioremediation of PAE and paraben-polluted environments.
研究领域:
环境科学
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生物化学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Dai-Xu Wei,Duanfang Cai,Youguo Tan,Kezhi Liu,Jin-Wei Dao,Xiang Li,Aikeremujiang Muheremu
Huperzine A (HupA) is used in Alzheimer's disease (AD) therapy for its effective inhibition of acetylcholinesterase (AChE) and enhancement of cholinergic neuronal function. However, direct oral administration and injection of HupA cause side effects like nausea, anorexia, and rapid metabolism. Using a tripolymer, poly(3-hydroxybutyrate- co -3-hydroxyvalerate-co-3-hydroxyhexanoate (PBVHx), from the polyhydroxyalkanoate (PHA) family synthesized via synthetic biology, we present a novel AD therapy strategy with peritoneally administered PBVHx microspheres loaded with HupA (HupA-PBVHxMs). This approach extends HupA's metabolic duration in the blood and brain, enhancing AChE inhibition efficacy. Uniformly sized HupA-PBVHxMs, created using microfluidics and rotary evaporation, show up to 70.4 % drug encapsulation efficiency, sustained HupA release for 40 days, reduced neurotoxicity from Aβ25–35, and maintained in vivo HupA supply and AChE inhibition for over 20 days. In cognitive tests, HupA-PBVHxMs improved function in AD mice. Thus, PBVHx microspheres with slower HupA release and lower biotoxicity offer a superior platform for sustained AChE inhibitor release, outperforming commercial PLGA microspheres.
研究领域:
药学
·
神经科学
·
生物技术
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2020
·
IF 2.678
Liang Zhao,Yinan Sun,Xiaoqiu Liu,Lihua Hong,Ju Niu,Chengji Zhao
In this paper, a novel polyurethane copolymer (PU) derived from hexamethylene diisocyanate (HDI), polycaprolactone (PCL) and tetramethyl biphenyl epoxy acrylate (TMBPEA) was synthesized, characterized, and designed to have controllable mechanical properties and shape memory ability. The multifunctional PU contains cystallizable PCL segments, cross-linkable C C bonds in TMBPEA and urethane moieties. Both the PCL crystalline phase and photo-crosslinking of C C bonds play an important role in determining the mechanical properties of PU. Therefore, by adjusting the degree of crystallinity and the degree of crosslinking, the mechanical properties of PU could be easily controlled and varied. Before photo-crosslinking, the crystallinity of PU increases from 33.01% to 78.97%, as the content of PCL in PUs increases. However, after photo-crosslinking, the degree of crystallinity was significantly reduced to 11.09% as the UV irradiation time increased. In this way, the mechanical properties of PUs could be readily controlled by adjusting the ratio of PCL in the PUs and varying the UV irradiation time. As the ratio of PCL in PUs increases, the tensile strength and Young’s modulus of PUs increases from 9.04 ± 1.26 MPa to 12.98 ± 0.33 MPa and 89.79 ± 5.74 MPa to 224.88 ± 5.22 MPa, respectively. Meanwhile, the elongation at break increases from 499.09 ± 88.38% to 776.51 ± 67.39%. After crosslinking, the Young’s modulus of UV-cured PUs decreased from 224.88 ± 5.22 MPa to 18.74 ± 1.30 MPa as the UV irradiation time increased. Moreover, the elongation at break of UV-cured PUs was also dramatically reduced to around 60 MPa after photo-crosslinking compared to pristine PUs. Furthermore, shape memory tests indicated that uncrosslinking PUs samples have shape memory ability.
研究领域:
材料科学
·
高分子化学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Jiarong Qiu,Yueqi Zhang,Yaning Shi,Junwei Jiang,Shenglu Wu,Longxiang Li,Yuting Shao,Zhihong Xin
Phthalate esters have raised public concerns owing to their effects on the environment and human health. We identified a novel phthalate-degrading hydrolase, EstJ6, from a metagenomic library using function-driven screening. Phylogenetic analysis indicated that EstJ6 is a member of family IV esterases. EstJ6 hydrolyzed various dialkyl and monoalkyl phthalate esters, and exhibited high hydrolytic activity (128 U/mg) toward dibutyl phthalate at 40 °C and pH 7.5. EstJ6 hydrolyzed not only common phthalate esters with simple side chains but also diethylhexyl phthalate and monoethylhexyl phthalate, which have complex and long side chains. Site-directed mutagenesis indicated that the catalytic triad residues of EstJ6 consists of Ser146, Glu240, and His270. EstJ6 is therefore a promising biodegradation enzyme, and our study illustrates the advantages of a metagenomic approach in identifying enzyme-coding genes for agricultural, food, and biotechnological applications.
研究领域:
环境科学
·
生物技术
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）