STARCH-STARKE
·
2021
·
IF 2.741
Lei Chen,Jing Li,Zia-ud Din,Chun Hu,Hanguo Xiong
Nanoparticle incorporation is a common strategy for promoting the performance of starch-based wood adhesive as low storage stability limits the application of conventional nanocomposite adhesives. This work focuses on the performance comparison of adhesives containing different nanoparticles (nano-TiO 2 , TK (TiO 2 -KH570), TKB (TiO 2 -KH570-Butyl acrylate)) to improve both the bonding strength and storage stability. The structure and morphology of these nanoparticles are characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. The results indicate that the surface modification improves the dispersion of nano-TiO 2 . After adding in adhesive, the results of shear strength, viscosity, and rheological properties signify that the structural strength within adhesive is related to the surface hydrophobicity and the thickness of the surface hydrophobic layer of functionalized nanoparticles. TKB exhibits excellent improvement on the storage stability of adhesive due to its wide surface hydrophobic layer weakening the intermolecular interaction. TK shows limited improvement on both bonding strength and storage stability as the hanging hydrogen groups from KH570 form cross-linking structure with other components in adhesive. Therefore, selecting the appropriate functional nanoparticles is an important parameter for designing high-performance wood adhesive for the veneer industry.
研究领域:
材料科学
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林产品工程
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DOI
高影响因子
STARCH-STARKE
·
2020
·
IF 2.226
Xiaodong Bai,Xuepeng Zhang,Yuqian Xu,Xuemei Yong
A graft copolymer is synthesized with graft copolymerization of acrylamide (AM) and 1-vinyl-2-pyrrolidone (NVP) grafting onto sodium carboxymethyl starch (CMS) via central composite design (CCD). The initiation system consists of potassium persulfate (KPS) and sodium hydrogen sulfite (SBS). The copolymer is confirmed by infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, scanning electron microscopy, thermogravimetric experiment, and elemental analysis. The rheological performance, filtration loss, cake thickness, and cake fictional coefficient of the drilling mud containing copolymer are evaluated. The results show that copolymers have ability to thicken and reduce filtration volume and have no obvious influence on the thickness and fictional coefficient of the mud cake. Response surface methodology (RSM) is exerted for variable evaluation and optimization. The results indicate that initiator concentration is the main contributing factor to decrease filtration volume and the optimum results are 1.5 wt% (initiator concentration), 1.82 (mole ratio of monomer to starch [AGU]), 66.02 °C (reaction temperature), 3.87 h (reaction time). The predicted value and the actual experimental value are 8.64 and 9 mL respectively with an error of 4.01%. The small error indicates that there is a small deviation between the actual and the predicted values, which also shows that the model is reasonable.
研究领域:
材料科学
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石油工程
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产品关联
DOI
高影响因子
STARCH-STARKE
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2024
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IF 2.6
Lian Li,Jia Zheng,Li Yao,Hong Wang,Yiyi Lv,Guichun Huang,Shuyi Qiu,Xiangyong Zeng,Chaoyang Wei
Baijiu distillers' grain is a solid waste after the fermentation of grains, and their high added value and deep processing and utilization require further study. This study uses the enzyme and microwave coassisted method to extract Baijiu distillers' grain polysaccharides (DGPs). Through optimization of the single-factor test and response surface methodology (RSM), the optimal conditions are solid–liquid ratio 1:30, enzyme time 50 min, enzyme temperature 50 °C, enzyme pH 5.0, microwave time 6 min, and microwave power 480 W, with a maximum DGP yield of 3.98% ± 0.03. DGP is purified by DEAE-Sepharose cellulose ion exchange chromatography to obtain four fractions, namely DGP-1, DGP-2, DGP-3, and DGP-4; the molecular weights are 2224.05, 90.99, 1478.16, and 346.19 kDa, respectively, and the main monosaccharide components are Man and Glc. The antioxidant assay shows that the four kinds of DGPs have different free radical scavenging capacities, among which DGP-2, DGP-3, and DGP-4 have good antioxidant activities. Therefore, DGP can be used as a potential natural antioxidant.
研究领域:
食品科学
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生物化学
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产品关联
DOI
高影响因子
STARCH-STARKE
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2020
·
IF 2.226
Linjuan Duan,Rongrong Liu,Qun Li
A more efficient Fenton oxidation method with high shear mixing for the preparation of cellulose nanofiber (CNF) is investigated. The Fenton reaction is the reaction between Fe 2+ and H 2 O 2 to produce a series of free radicals that leads to oxidation of the cellulose. With the new technology, the Fe 2+ is preloaded into the kraft pulp by a high shear refining method to realize in situ oxidation of cellulose fibers. It is found that the carbonyl content in the fibers using high shear mixing process is 149.79 μmol g −1 when the dosage of hydrogen peroxide is 0.08 g/g (weight of dry fibers), compared to the 126.40 μmol g −1 of fiber without high shearing when the dosage of hydrogen peroxide is 0.15 g/g, which indicates that the new Fe 2+ pre-loading process has higher oxidation efficiency with lower H 2 O 2 consumption compared with traditional Fe 2+ preloading process. The 13 C NMR results show that the C 2 , C 3, and C 6 hydroxyl groups are oxidized to aldehyde and carboxyl groups, which is beneficial to increase the electrostatic repulsion between fibers and facilitate the subsequent homogenization treatment. The obtained CNF is uniform in size and slightly lower in thermal stability.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
STARCH-STARKE
·
2019
·
IF 1.795
Li Guo,Hui Li,Lu Lu,Feixue Zou,Haiteng Tao,Bo Cui
To illuminate the relationship between the branch chain structures and physicochemical characteristics of cassava starch and to expand the range of its functionality, cassava starch granules are modified with sequential α-amylase from hog pancreas , barley β-amylase, and transglucosidase from Aspergillus niger . The molecular weight and amylose contents of the enzyme-modified starches decrease, and the modified starches exhibits increased numbers of short and medium chains and a higher branch density compared with those of control starch. The crystal pattern is transformed from A-type to a mixture of A-type and V-type, and the crystallinity is reduced. The enzyme-modified starches exhibits increased solubility and paste clarity, a more homogeneous crystal distribution, and reduced gelatinization temperatures, gelatinization enthalpy, and viscosity compared with those of control starch. The enzyme-treated starches exhibit a larger elasticity modulus, a viscous modulus, and a reduced loss angle tangent when the range of the transglucosidase treatment time is from 2 to 4 h, whereas the opposite effect is observed when the transglucosidase treatment time ranges from 8 to 10 h. These findings demonstrate that the rheological properties of the enzyme-modified starch are significantly dependent on the time of the transglucosidase treatment. Thus, triple enzyme modification may supply a new potential method to obtain the expected hydrophilic, rheological, and thermal properties of cassava starch.
研究领域:
食品科学
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生物化学
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DOI
高影响因子
STARCH-STARKE
·
2019
·
IF 1.795
Jia Shao,Zheng Zhang,Shixing Zhao,Sui Wang,Zhiyong Guo,Hongzhen Xie,Yufang Hu
As promising soft materials, various excellent properties of hydrogels have received widespread attention during recent years. Mechanical properties and self-healing performance are required characteristics for hydrogels in practical applications. An important challenge is to develop hydrogels exhibiting mechanical performance and self-recoverability through physical cross-linking. In this work, the authors report a hydrogel consisting of a fully physically linked poly (vinyl alcohol)/agarose (PVA/AG) dual-network, which is of high toughness and self-healing properties. The synthesis process of the PVA/AG hydrogel is convenient, with AG as the first network, and hydrogen bonding and crystal-associated PVA as the second network to form a dual physical crosslink. Due to this physical cross-linking, the PVA/AG hydrogel has good mechanical properties (tensile strength of 6.5 MPa to 14.6 MPa, ductility of 168% to 214%). The highest compressive strength of hydrogel is up to 3.66 MPa, which is almost 8 times that of pure PVA hydrogel. In addition, it has excellent self-healing properties without stimulation or healing agents. Compared to pure PVA hydrogel, PVA/AG hydrogels have higher thermal stability due to higher decomposition temperatures and lower degradation rates. In this study, the authors also initially explore the potential application of obtained hydrogel.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
STARCH-STARKE
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2018
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IF 2.173
Sarkodie Bismark,Zhang Xun,Zhu Zhifeng,Frimpong Charles,Badoe William,Asinyo Benjamin,Howard K. Ebenezer
In this study, amphiphilic starch prepared by phosphorylation and octenylsuccinylation is surveyed to identify its effect on the adhesion of starch to cotton/polyester blend fibers at different temperature. Acid-thinned cornstarch (ATS) is phosphorylated and octenylsuccinylated with pentasodium triphosphate and 2-octenylsuccinic anhydride, respectively, to improve upon adhesion to cotton/polyester blend fibers. Two series of amphiphilic starch samples with different levels of the substitution (DS) are derived for determining desirable level of starch modification in sizing. Amphiphilic starch paste shows strong adhesion to cotton/polyester blend fibers than ATS paste. It is found that the modification reduces the crystallinity, changed the morphology, improves moisture regain, alleviates the adverse influence of starch retrogradation, and improves adhesion to fibers and desizing efficiency. The adhesion of amphiphilic starch paste to cotton/polyester blend fibers at 60 °C is statistically higher than adhesion of ATS at 95 °C. The amphiphilic starch with a total DS of 0.06 shows the highest potential use for strong cotton/polyester blend warp sizing due to its good sizing properties.
研究领域:
材料科学
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纺织工程
·
有机化学
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产品关联
DOI
高影响因子
STARCH-STARKE
·
2019
·
IF 1.795
Wei Meng,Fangping Chen,Chenhao Zhang,Ruihua Cui,Peilei Wang,Changsheng Liu
In this study, a high-efficiency polyurethane prepolymer (PUP) compatibilizer is developed to improve the compatibility between cassava starch and poly(butylene adipate-co-terephthalate) with higher molecular weight (MPBAT). Preferentially, modified starch (MS) is prepared by reacting isocyanate groups of PUP with hydroxyl groups of starch in a high-speed mixer, and then starch-based MPBAT composites (MSPT) with PUP as a compatibilizer are continuously extruded using twin-screw extruder. The mechanical properties, water absorption, and thermodynamic properties as well as morphology of MSPT are investigated with different PUP contents and at the same mass ratio of MPBAT to starch (1:1). Samples of MSPT-2 provide satisfactory mechanical properties comparable to control samples. Addition of 13 wt.% PUP to MSPT, improves tensile strength from 3.8 to 11.9 MPa and increases elongation at break from 93.3 to 580.4% at room temperature compared with control without the PUP. The hydrophobicity and thermostability properties of MSPT-2 composites are also enhanced. The results further prove that MSPT-2 composites possess excellent compatibility, not only because of the urethane bonds of the PUP and starch, but also stemming from the physical crosslinking between soft segment of PUP and aliphatic segment of MPBAT. Starch-based MPBAT composites with excellent compatibility and high toughness will help broaden the application field of biodegradable plastics.
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
STARCH-STARKE
·
2019
·
IF 1.795
Ri-Hui Lin,Yan-Ye Fan,Tao Liu,Hui Yang,Li-Juan Ma,Xia-Jie Huang,Yue Liu
Native starch granule has a complex crystalline structure. Controlled decrystallization cassava starch (CDCS) was prepared by the alcohol–alkali method. Polarized microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis of the CDCS are carried out to investigate its structural information. The results show that the relative crystallinity (RC) of the processed cassava starches can be reduced from 25.56% to 17.90% by adjusting the concentration of sodium hydroxide while keeping the integrity of the starch granule. During the decrystallization process, as the sodium hydroxide concentration is increased from 0.25 to 1.25 mol L −1 , the polarized light of the starch granules disappear from the inside to the outside, and the X-ray diffraction peaks of native cassava starch (NCS) disappear sequentially from 17.16°, 23.04°, 15.08°, to 17.83°. On the other hand, the FTIR peaks of the NCS centered at 1645 cm −1 is shifted to about 1600 cm −1 , and the intensity of the peaks at 3424, 2929, 1645, and 1017 cm −1 become weaker with decrystallization process. This study provides valuable data and a theoretical basis to understand the mechanism of the controlled decrystallization of cassava starch.
研究领域:
食品科学
·
材料科学
·
植物学
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产品关联
DOI
高影响因子
STARCH-STARKE
·
2020
·
IF 2.226
Rongli Zhang,Fangwen Chu,Yunqin Hu,Huiling Hu,Yulong Hu,Huan Liu,Chaofei Huo,Hao Wang
A photo-crosslinking cinnamic acid-modified starch (CA-St) copolymer is synthesized through an esterification reaction using 4-dimethylaminopyridine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide as catalysts. The structure of the CA-St is confirmed by 1 H nuclear magnetic resonance and infrared spectroscopy. Using the nanoprecipitation method, the photo-crosslinking CA-St copolymer is aggregated into colloidal particles (CPs). The formation process and photo-crosslinking of CA-St CPs are evaluated in terms of size distribution, and ultraviolet and visible spectrophotometry. The scanning electron microscopy shows that the CA-St CPs comprise spherical particles with a diameter of approximately 410 nm. This type of photo-crosslinking CP has potential applications in nano- and biotechnology fields.
研究领域:
材料科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
STARCH-STARKE
·
2021
·
IF 2.741
Qiujie Fang,Na Chen,Shan Hu,Sheng Hu,Jianfeng Ye,Xiaozhou Ye,Yun Wang
Some special oral drugs may cause adverse reactions and degrade in the stomach; therefore, it is necessary to develop a new generation of multifunctional drug delivery carries to deal with such issues. Herein, by polyelectrolyte composite method using KGM and CS as raw material, CKGM/CS/TPP/5-ASA microcapsules are prepared using 5-ASA as model drug, and then coated with an acid-resistant polyacrylic acid polymer layer. The size of CKGM/CS/TPP/5-ASA microcapsules is relatively uniform, with average particle size 1.78 ± 0.02 mm. The inner part of microcapsules has a core-shell three-dimensional network structure, and the 5-ASA embedded in the network is in its crystal form. The microcapsules exhibited good encapsulate properties, with 495.5 µg mg −1 drug loading amount and 82.3% encapsulation efficiency under optimized conditions. The in vitro release properties of microcapsules are also studied, and results showed that the drug is released little in Simulated Gastric Fluid solution (pH 1.2) but fully released in Simulated Colonic Fluid or Phosphate Buffered Solution (pH 7.0), and the release rate is higher in SCF solution, indicating that β-mannanase could facilitate release. All these results indicated that CKGM/CS/TPP microcapsules have good pH-controlled release, enzymatic release, and sustained release properties, hence they are promising multifunctional colon-targeted release carriers.
研究领域:
药学
·
生物材料学
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产品关联
DOI
高影响因子
STARCH-STARKE
·
2021
·
IF 2.741
Meidong Li,Xiufang Huang,Qin Zhang,Yifeng Zhou,Kai Luo
Four new types of water-soluble polysaccharides are isolated from Cardamine hupingshanensis . Herein, this study examines C. hupingshanensis polysaccharide no. 2 (CHP-2) with a molecular weight of 21.75 kDa. Analysis revealed that CHP-2 is composed of d -glucuronic acid, d -galacturonic acid, glucose, galactose, and L-arabinose. It is speculated that the main connecting bond is →4)-α-D-Glc(p)-(1→), →t)-α-D-Glcp-(1→). Through perfusion experiments using streptozotocin-induced diabetic rats, oral CHP-2 solution is found to significantly reduce food intake, water intake, and fasting blood glucose levels, while increasing the weights of rats. In addition, CHP-2 significantly reduces the serum and liver malondialdehyde contents and increases the activity of the corresponding antioxidant enzymes. Moreover, the effect elicited by the CHP-2 solution is similar to that of phenformin hydrochloride solution. Hence, the results of this study suggest that CHP-2 exhibits blood sugar-lowering and anti-oxidation effects.
研究领域:
药理学
·
生物化学
·
糖尿病研究
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）