PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
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2020
·Vol. 16
·期 8
·1211-1219
·
IF 2.831
Liao Wanfeng,Ni Xiuyuan
Photopolymerization, which is one of the most attractive polymerization methods, has been recently studied for the development of new photoinitiators. Herein, we use a binary mixture of titanium dioxide (TiO 2 ) nanoparticles and carboxylic diacid as a novel photoinitiator to initiate the free radical polymerization of vinyl acetate (VAc). The polymerization of VAc is achieved both in aqueous medium and bulk. The initiation mechanism of TiO 2 /diacids is studied via nuclear magnetic resonance (NMR) spectroscopy using 13 C labeled diacids as probing molecules. Further, a universal reaction mechanism is established, where the polymerization of VAc is initiated by the HOOC-R˙ radical, which is generated from the photocatalytic decarboxylation of the diacid. The polymerization kinetics results indicate that the polymerization rate is strongly dependant on the diacid structure. Compared to the use of diacids with an odd number of carbons, it is found that using diacids with an even number of carbons results in the polymerization rate reaching the maximum value faster.
研究领域:
材料科学
·
化学工程
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DOI
PubMed
高影响因子
POLYMER
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2025
·
IF 4.5
Pengkai Qin,Linbo Wu,Suyun Jie
Two series of high molecular weight aliphatic-aromatic random copolyesters: PBXT, where X represents the carbon atom number of the aliphatic α,ω -diacids, PBXT 48 and PBXT 50w (X = 4–14, even), with molar and mass copolymer compositions (48 mol% and 50 wt%) equal to those of commercial poly(butylene adipate-co-terephthalate) (PBAT) were synthesized from butanediol, terephthalic acid and various aliphatic α , ω -diacids. They were characterized with 1 H NMR, and their melt crystallization, optical, mechanical and gas barrier properties were assessed. In these copolyesters, the melt crystallization of butylene terephthalate (BT) sequence is dominant, while the butylene adipate (BX) sequences can also crystallize from melt when the BX content is high enough, the chain length of α , ω -diacid unit or the crystallization time is long enough. Long enough chain length of α , ω -diacid unit ( X ≥ 6) endows PBXT with sufficient chain flexibility/mobility and, therefore, excellent melt crystallizability at rapid cooling. For PBXTs with X ≥ 6, the effect of X on BT crystallization is not monotonic. In particular, both PB6T and PB12T displayed a higher melt crystallization temperature than the adjacent PBXTs. Compared to PB6T, PB4T has higher transparency and gas barrier properties; with increasing X from 6 to 14, the PBXTs show increased transparency and water vapor barrier, but decreased oxygen barrier performance. The tensile modulus and strength of PBXT decrease, and the elongation at break increases with increasing X . But the effect of X is clearly weakened for PBXTs with the same mass composition of 50 wt%.
研究领域:
材料科学
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高分子化学
·
物理化学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Han Hu,Jiayi Li,Shenggan Luo,Ying Tian,Jinggang Wang,Yi-Lei Zhao,Ruoyu Zhang,Jin Zhu
Nowadays, the promotion and application of aliphatic-aromatic copolyesters, such as poly (butylene adipate–co–terephthalate) (PBAT), are growing into a general trend. Although the structures of diacids exerted substantial impacts on degradation behavior, the underlying mechanisms have rarely been studied. In this work, 2,5-Furandicarboxylic acid was combined with succinic acid (PBSF), adipic acid (PBAF) and diglycolic acid (PBDF) to prepare three kinds of copolyesters. They showed unique degradation behaviors in buffer, enzyme environment and artificial seawater. These characteristics are closely related to the structural compositions of diacids. PBAFs displayed impressive biodegradability when catalyzed by Candida antarctica lipase B (CALB), while the more hydrophilic PBDFs exhibited faster hydrolysis in both buffer and artificial seawater. PBSFs, with hydrophobic and short segments, obtained a relatively slower rate of hydrolysis and enzymatic degradation. The reactivity sites and hydrolytic pathway were revealed by the combination of DFT calculation and Fukui function analysis. MD simulations, QM/MM optimizations and theozyme calculations showed that PBAF-CALB was prone to form a pre-reaction state, leading to the reduced energy barrier in the acylation process. This work revealed the effects of different structural features of diacids on polymer degradation and paved a way to design target biodegradable polymers in different degradation conditions.
研究领域:
材料科学
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环境科学
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生物化学
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DOI
高影响因子
EUROPEAN JOURNAL OF MASS SPECTROMETRY
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2017
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IF 1.022
Dengyang Yin,Xunxiu Hu,Dantong Liu,Wencheng Du,Haibo Wang,Mengzhe Guo,Daoquan Tang
Liquid chromatography coupled with mass spectrometry technique has been widely used in the analysis of biological targets such as amino acids, peptides, and proteins. In this work, eight common single carboxylic acids or diacids, which contain different pKa have been investigated as the additives to the analysis of amino acids. As the results, carboxylic acid additive can improve the signal intensity of acidity amino acids such as Asp and Glu and the chromatographic separation of basic amino acids such as Arg, His, and Lys. In particular, the diacids have better performance than single acids. The proposed mechanism is that the diacid has hydrogen bond interaction with amino acids to reduce their polarity/amphiprotic characteristics. Besides, oxalic acid has been found having better enhancement than phthalic acid by overall consideration. Therefore, we successfully quantified the 15 amino acids in Sepia bulk pharmaceutical chemical by using oxalic acid as the additive.
研究领域:
分析化学
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生物化学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Jiyang Zuo,Tao Yang,Chen Lin,Hongxia Deng,Shanshan Gu,Fei Liu,Zhisen Shen,Jin Zhu,Jinggang Wang
This work provides an in-depth molecular structure design strategy for developing high-barrier polymer packaging films. A series of high-performance PPDThF copolyesters were prepared by utilizing the unique crystallization ability of poly(propylene 2,5-thiophenedicarboxylate) (PPThF), as well as a long-chain dicarboxylic acid, namely dodecanedioic acid (DA). The incorporation of a polyethylene-like polyester structure from DA into the main chain of polymers has been found to be random copolymerization, leading to limited crystallizable sequence lengths. The effects of the long-chain dicarboxylic acids on the thermal transition, aggregation structure, gas barrier properties, and optical properties of the copolyester PPDThF copolyesters were investigated. The results demonstrate that PPDThF-10 combines the benefits of conventional thermoplastics, like high strength (>30 MPa) and high modulus (>0.6 GPa), with the mechanical and physical characteristics of chemically cross-linked rubber, including high extensibility (ε = 730%) and toughness (134 MJ/m–3). The results obtained so far demonstrate that thiophene-based copolyesters can be used in food packaging applications.
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
SOLAR ENERGY
·
2017
·
IF 4.018
Shang Liu,Lipeng Han,Shaolei Xie,Yongzhong Jia,Jinhe Sun,Yan Jing,Quanyou Zhang
Low stability, reliability, and corrosion are considerable challenges to widespread application of succinic acid (SA) as phase change material (PCM). Here, we present a novel medium-temperature form-stable phase change material (FSPCM) aiming to eliminate these obstacles. In this study, FSPCM was fabricated by adsorbing eutectics of adipic acid (AA) and SA into expanded graphite (EG). The molar ratio of AA and SA in eutectics was determined to be 7:3, and the optimal mass ratio of EG in FSPCM is ca. 0.1. The composite was characterized by diffraction scanning calorimetry, scanning electron microscopy, Fourier transform infrared spectrometer, X-ray diffractometer, and thermal gravimetric analyzer. The results showed that the FSPCM melts at ca. 135 °C with latent heat storage of 206 J/g. No notable change of thermal behavior in FSPCM was observed after experienced 100 accelerated cycle test. Compared to SA, both the stability and reliability were promoted in FSPCM. Besides, the leakage of dicarboxylic acid was prevented, thus the corrosion was alleviated. It is envisioned that the as-prepared FSPCM have considerable potential in medium-temperature latent heat storage.
研究领域:
材料科学
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能源存储
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产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2023
·Vol. 31
·期 11
·4770-4783
·
IF 5.3
Wang Guoqiang,Wang Jianyu
In this work, the melt polycondensation method was used to synthesize aliphatic polyesters from 1,12-dodecanediol and aliphatic diacids with even carbon atoms. Gel permeation chromatography, hydrogen-1 nuclear magnetic resonance ( 1 H NMR), infrared spectroscopy, differential scanning calorimetry, wide-angle X-ray diffraction, thermogravimetric analysis, tensile test, dynamic mechanical analysis, and rotational rheometer were used for characterization. All polyesters had high weight average molecular weight (> 60,000 g/mol). Poly(1,12-dodecylene adipate) had the lowest weight average molecular weight (66,360 g/mol) and poor thermal stability. Four polyesters had very flexible molecular chains and shared a crystalline structure with polyethylene. Poly(1,12-dodecylene octanedioate) and poly(1,12-dodecylene sebacate) had tensile strength of 20.8 MPa and 25.3 MPa, respectively, and elongation at break of 255% and 254%, respectively, meaning that their tensile properties were similar to those of polyethylene.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2017
·
IF 5.951
Xiao-Lin Wang,Li Chen,Jia-Ning Wu,Teng Fu,Yu-Zhong Wang
In this study, novel biobased pressure-sensitive adhesives (PSAs) derived from epoxidized soybean oils and carboxylic acid-terminated polyesters were developed with flame retardance, thermal stability, and peel strength comparable to those of current PSAs. The dynamic mechanical analysis indicated that the PSAs exhibited a dynamic mechanical response consistent with related high-performance PSAs. The thermal properties of the PSAs were investigated by thermogravimetric analysis, and the results suggested that the onset decomposition temperatures in both nitrogen and air atmospheres were improved by incorporating both 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phosphaphenanthrene-10-oxide (DDP) and 2-(6-oxido-6H-dibenz<1,2>oxaphosphorin-6-yl)-1,4-hydroxyethoxyphenylene (DOPO-HQ-HE) as the flame-retardant monomer. Microscale combustion calorimetry, the limiting oxygen index test, UL-94, and the test method for flame resistance of PSA tapes were used to evaluate the flame retardance of the PSAs. With an increase in the content of the flame-retardant monomers, the flame retardance of two phosphorus-containing PSAs improved. The PSAs were based on renewable materials without any volatile organic compound, thus being environmentally friendly together with having the expected thermal stability and flame retardance. If we take advantage of these features, the PSAs can provide more opportunities for versatile applications.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Shengdu Yang,Yushun He,Junhua Zhang
Despite the significant progress in high thermal-resisting photocurable resin, the simultaneous achievement of robustness, stretchability, and dielectric properties in modified naphthalene-type photocurable resin remains a great challenge owing to intrinsic restrictions mediated by strong π-π stacking effect. Herein, a simple and feasible method is demonstrated to respectively introduce three selected di-functional acid chain extenders into 1,6-naphthalene diglycidyl ether (NDE), and prepare a series of naphthalene-type photocurable enhancement resin with excellent thermal/mechanical properties and low dielectric traits. Most importantly, the effect of the increase of succinic acid (SA) chain-extending segments on the thermal and mechanical properties of SA chain-extending NDE (S-NDE) resin is systematically investigated. An optimized synthesized route is presented by chain extension chemical strategy, which enables the improvement of the “seesaw” issue between high heat resistance and mechanical robustness. As a consequence, the optimized UV-curing S-NDE thin film exhibits robust tensile strength (75.45 ± 4.46 MPa), excellent heat resistance (T g : 145.4 °C), high stretchability (7.22 ± 0.85 %), and desired dielectric constant (2.2). Meanwhile, the uncured S-NDE resin exhibited an excellent alkali elution property within 5 min. An actually printed circuit board (PCB) solder resistance coating/patterning application is further demonstrated based on the selective elution property of high-performance formulated S-NDE green ink, providing an efficient strategy for the design and fabrication of high-performance naphthalene-type photocurable materials.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2024
·
IF 6.1
Jiaxuan Li,Songping Mo,Bo Xiao,Qing Li,Lisi Jia,Ying Chen
Microencapsulation enhances the performance of phase change materials (PCMs). However, the existing research on microencapsulation of dicarboxylic acids (DAs) is inadequate, with only one study dedicated to the development of microcapsules containing a low DA content and a shell that decomposes at low temperatures. In this study, glutaric acid (GA), as a representation of DA, was successfully microencapsulated with an enhanced encapsulation ratio. The results obtained by scanning electron microscopy (SEM) revealed a uniform spherical core–shell structure of the microencapsulated GA (MEGA). Fourier transform infrared spectroscopy (FT-IR) an X-ray diffractometer (XRD) analysis confirmed the absence of any chemical reaction between the core and shell materials. Additionally, differential scanning calorimetry (DSC) results demonstrated excellent heat storage. Notably, MEGA exhibited a thermal reliability index of 94.4 % after 200 accelerated thermal cycles. Thermogravimetry analyzer (TGA) results showed good thermal stability of MEGA. The dispersion stability and thermal conductivity of MEGA suspensions displayed significant enhancements compared to those of GA suspensions. Furthermore, compared with the base fluid, the MEGA suspensions with 1.0 wt%, 5.0 wt% and 10.0 wt% demonstrated reduced pumping power requirements by 16.9%, 54.6% and 70.0%, respectively. These findings suggest that MEGA holds promising prospects for applications in the medium temperature energy storage field.
研究领域:
材料科学
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热能工程
·
能量存储
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xinyi Wang,Qinrui Chen,Juanjuan Wen,Chengyu Nie,Wei Ke,Xiaowei Da,Xianfu Chen,Minhui Qiu,Yiqun Fan
Long-chain dicarboxylic acids (LCDAs) are important basic chemical raw materials, and their bio-synthesis has gained increasing prominence in recent years. However, the pigments formed during the biological process have a significant impact on the purity of the product. In this study, a TiO 2 -ZrO 2 ceramic nanofiltration (NF) membrane with tunable pore size was developed and used for efficient decolorization of LCDA fermentation broth. Based on the inhibitory effect of Ti doping on ZrO 2 phase transition, combining the steric hindrance effect of organic residues, NF membranes with regulable molecular weight cut-off (600/1100/1600 Da) can be achieved by controlling calcination temperature in range of 350–450 ℃. They all have a rejection of over 98.8 % for the larger molecular weight pigments (DY9, AY3 and AY23), and the rejection for the smaller SY pigment is also above 90 %. In addition, the NF membranes exhibited excellent performance in crude sebacic acid aqueous solution. With a sebacic acid salt rejection of less than 5 % and a pigment rejection of over 90 %, they achieved simultaneous efficient decolorization and product recovery. Finally, the multi-channel NF membrane prepared at 400 ℃ calcination temperature achieved excellent decolorization performance in the real dodecanedioic acid fermentation broth, increasing the purity of acid after acidification crystallization from 98.62 % to 99.56 %. This verified its application potential in the industrial treatment of LCDA fermentation broth.
研究领域:
材料科学
·
化学工程
·
膜分离技术
·
生物化工
·
纳米材料
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 31
·46531
·
IF 1.901
Guangji Zou,Pingli Wang,Wutong Feng,Zhonglai Ren,Junhui Ji
Poly(decamethylene terephthalamide) (PA10T), a bio-based high-performance semi-aromatic polyamide, has been commercialized in recent years. However, there still are some weaknesses restricting its application range, such as narrow melt processing window and low ductility. In this study, we chose dodecanedioic acid (a potential bio-based raw material) as the comonomer to prepare copolyamides [poly(decamethylene terephthalamide/decamethylene dodecanediamide), PA10T/1012] for solving these problems. The basic properties of these copolyamides were characterized by viscosity measurement, Fourier transform infrared spectrometer, proton nuclear magnetic resonance, wide-angle X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and tensile measurement. Results show that, compared to PA10T, PA10T/1012 exhibits wider melt processing window and more outstanding elongation at break. Meanwhile, PA10T/1012 is still qualified for high temperature resistant material. Furthermore, T g , T d ,5% , T d ,10% , and T d ,max of PA10T/1012 show a linear dependence on 1012 content, which is helpful to design new bio-based copolyamides for meeting the needs of various occasions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46531.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）