CHINESE JOURNAL OF POLYMER SCIENCE
·
2024
·
IF 4.1
Zhang Xin-Rao,Wang Fu-Shan,Wang Xin,Gao Yan,Zhang Hong-Xing,Liu Zhi-Qin,Feng Jia-Chun
Although Ziegler-Natta (Z-N) polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging, the migration of acid scavengers, an additive usually introduced in Z-N polyolefins, from the packaging to its contents has not been reported. In this work, the migration of the two most used acid scavengers, calcium stearate (CaSt 2 ) and zinc stearate (ZnSt 2 ), from a Z-N polypropylene random copolymer (PPR) into water during autoclaving at 121 °C were comparatively investigated. It was found that, for PPR plates containing 0.1 wt% CaSt 2 or ZnSt 2 (PPR-0.1CaSt 2 , PPR-0.1ZnSt 2 , respectively), the concentration of migrated calcium ion into water increased with autoclaving time, while that of zinc ion was much lower at same treatment durations and did not show a significant increase with treatment time. Interestingly, after removing all plates and acidification treatment, a considerable amount of stearic acid was detected in sterilized water for PPR-0.1ZnSt 2 , but no such significant stearic acid was detected in sterilized water for PPR-0.1CaSt 2 . Based on the structural evolution of the two soaps upon heating, possible mechanisms for the different migration behavior of CaSt 2 and ZnSt 2 from PPR into water during autoclaving treatment were proposed. Our results suggest that the migration issue of acid scavengers is worthy of attention in pharmaceutical packaging materials produced from Z-N polyolefins.
研究领域:
材料科学
·
食品科学
·
药学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Heliang Du,Xiaoyong Wang
The gel-like phase constructed by fatty acid compounds is a kind of fascinating soft matters but its structural characteristics have not been fully understood. This work has investigated the crystalline structures and formation mechanism of gel-like phase containing potassium stearate (KS), stearic acid (SA), and water at 80% neutralization degree. The crystalline fibers are observed in the gel-like samples of KS-SA-water on the polarized optical microscopy . X-ray diffraction measurement demonstrates that there are two isolate types of lamellar crystallites of KS and KS-SA complexes instead of the mixed crystallites in KS-SA-water samples. While KS crystallites have shorter Bragg spacing and tilted angle than the crystallites of KS-SA complexes, it is found that the solvent of water does not penetrate in the interlayer of two kinds of crystallites. The dynamic rheology measurement suggests the strong elasticity of KS-SA-water samples, which indicates the network structure formed by the lamellar crystalline fibers entrapping water. The addition of glycerol does not affect the crystalline structures of KS-SA-water samples, but significantly increase the values of storage modulus and melting enthalpy . This result suggests that the added glycerol can promote the strength of the hydrogen bonding between the solvent and crystalline fibers in the network structure of KS-SA-water samples. These findings provide new insights to the structural properties of gel-like phase of fatty acid compounds, which are importantly helpful for controlling their structure and functions.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Xinrao Zhang,Fuqing Wei,Zhuoni Wang,Guangquan Li,Shiyuan Yang,Jiachun Feng
Zinc stearate (ZnSt 2 ) and calcium stearate (CaSt 2 ) are two kinds of extensively used additives in polymer industry. However, the selection principle of the two soaps in different polyolefins is still unclear. To establish the action mechanism of these soaps in polyolefins application, the understanding of the exact structures when they play roles is prerequisite. In this work, considering that these additives play their roles during the melt processing of polyolefin, in which the structure may be different with their as-received states, the structures and evolution behavior of the two soaps in a polyolefin melt upon heating and cooling were systematically explored. It was found that the two soaps exhibited different dispersed structures and evolution behavior in the polypropylene random copolymer (PPR). The ZnSt 2 in PPR presented microcrystal at low temperatures and dissociated into ionic clusters during heating, and then gradually aggregated and recrystallized upon cooling; while the CaSt 2 in PPR exhibited vitreous agglomerates with lamella ordered structure at low temperatures and transformed to diverse colloidal liquid crystal aggregates during heating, and then gradually reassembled to vitreous agglomerates in cooling process. At concentration closed to practical application (about 1000 ppm or less), ZnSt 2 in molten PPR dispersed in form of ionic clusters like closed small molecules, whereas CaSt 2 in PPR melt presented weakly ordered aggregates. These findings provided an important foundation for building up the well-defined relationship between the structure and performance of these soaps in polyolefins.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2018
·
IF 5.651
Shangde Sun,Gaoshang Wang,Ping Wang
Monoricinolein (MRO) and diricinolein (DRO) were renewable and biodegradable lubricants . In this paper, MRO and DRO were prepared by the novel cleaner enzymatic glycerolysis of castor oil (CO) in solvent-free system. Three commercial immobilized lipases (Novozym 435, Lipozyme RM IM and Lipozyme TL IM) were screened and compared, and Novozym 435 showed the best catalysis performance among the tested lipases. Effects of reaction variables (reaction pressure, reaction time, temperature, enzyme load, substrate ratio and water content) on the enzymatic glycerolysis of CO were investigated. High conversion of CO (92.48 ± 1.02%) and the maximum bio lubricants yields (54.47 ± 0.58% MRO and 38.01 ± 0.50% DRO) were achieved under the following conditions: enzyme load 5% (w/w, based on the total mass), CO/glycerol ratio at 1:6, 90 °C, and 3 h. The activation energies (Ea) for CO conversion and the formation of MRO and DRO were calculated as 33.75 kJ/mol, 22.26 kJ/mol and 24.37 kJ/mol, respectively, and the process showed high selectivity toward the formation of MRO. Reaction kinetic agreed with the ping-pong Bi-Bi mechanism with the inhibition of CO, and the kinetic values ( V max , K m ′ and K IA ) were 0.0946 mol/(L·min), 1.6704 mol/L, and 0.89 mol/L, respectively.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
Food & Function
·
2022
·Vol. 13
·期 9
·5317-5326
·
IF 6.317
Zipeng Liu,Ling Chen,Bo Zheng
The nutritional design of personalized starchy foods has become a research hotspot in the field of food science. Driven by the immense functional and nutritional implications of starch–lipid binary interactions, this study is aimed at designing starch digestibility by controlling the interaction between starch and glycerol monostearate (GMS)/stearic acid (SA) using a hot-extrusion 3D printing (HE-3DP) environment. The results indicated that the thermal shear force in the HE-3DP environment promoted hydrophobic interactions between starch and lipids, forming a V-type starch–lipid complex with a compact and ordered structure, thus enhancing enzymatic resistance. Compared with GMS, SA with linear hydrophobic chains was inclined to compound with starch to form a more ordered structure. Interestingly, the slowly digestible starch (SDS) and resistant starch (RS) content reached 25.06% when the added SA content was 10%. Besides, correlations between the structural parameters and digestibility were established, which provided crucial information for designing nutritional starchy food systems using HE-3DP.
研究领域:
食品科学
·
营养学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Ningning Bai,Qing Li,Hongzhou Dong,Cui Tan,Peng Cai,Lan Xu
Self-recovering superhydrophobic coatings (SHCs) have drawn much attention in recent years because of their unique self-recovering properties and potential industrial applications. In this study, self-recovering SHCs based on recovery of structural damage have been successfully fabricated by spraying the mixture of polymethylmethacrylate/zinc stearate/stearic acid. The SHCs display a static contact angle (CA) of 158°, a sliding angle (SA) of 1° and exhibit a rough structure as shown in the SEM images. By acid rain (pH ≈ 3.5) scouring, the coatings maintain CA of 134° and high adhesion due to the broken morphology. Interestingly, the coatings restored superhydrophobicity after immersion in water for several minutes. Furthermore, the SHCs exhibit good long-term stability, water-durability and UV-durability, adapting to out-door environment. Above all, the coatings are environmental, low cost and can be quickly coated on various large-scale substrates, which will widen their practical applications.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
REPRODUCTION
·
2023
·
IF 3.8
Min Chen,Jia-Lu Shi,Zi-Meng Zheng,Zhi Lin,Ming-Qing Li,Jun Shao
The autophagy of trophoblasts is necessary for developing and maintaining of a healthy pregnancy. Autophagy dysfunction in trophoblast cells is linked to recurrent spontaneous abortion (RSA). However, the mechanism underlying trophoblast autophagy is unknown. In this study, we investigated the expression of autophagy-related genes in both normal and RSA villi. We also examined the production of lysophosphatidic acid (LPA) and lysophosphatidic acid receptor1 (LPAR1) in trophoblast cells during early pregnancy. We found that the activation of the LPA-LPAR1 axis triggered the autophagy of trophoblast cells and increased the expression of sodium/hydrogen exchanger 1 (NHE1). Inhibition of NHE1 suppressed the autophagy in trophoblast cells and we confirmed that NHE1 regulates LPA production in trophoblast cells. Additionally, we found decreased expression of autophagy-related genes and LPAR1 in villi from RSA patients. These observations indicate that the LPA/LPAR1-NHE1 axis regulates the autophagy of trophoblast cells during pregnancy. Insufficient autophagy and poor expression of LPAR1 in trophoblast cells may result in dysfunction of the trophoblasts and increased risk of spontaneous abortion. Overall, our research elucidated that a positive LPA/LPAR1-NHE1 axis can promote the autophagy of trophoblast cells and the abnormal axis leads to the autophagy deficiency of trophoblast cells in recurrent spontaneous abortion.
研究领域:
妇产科学
·
分子生物学
·
生殖医学
✓ 已验证
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 8
·1887
·
IF 5
Hui Fang,Guifeng Li,Kai Wang,Fangjuan Wu
This study investigates the effect of adding stearic acid (SA) on the thermal conductivity of polyamide 6 (PA6)/boron nitride (BN) composites. The composites were prepared by melt blending, and the mass ratio of PA6 to BN was fixed at 50:50. The results show that when the SA content is less than 5 phr, some SA is distributed at the interface between BN sheets and PA6, which improves the interface adhesion of the two phases. This improves the force transfer from the matrix to BN sheets, promoting the exfoliation and dispersion of BN sheets. However, when the SA content was greater than 5 phr, SA tends to aggregate and form separate domains rather than being dispersed at the interface between PA6 and BN. Additionally, the well-dispersed BN sheets act as a heterogeneous nucleation agent, significantly improving the crystallinity of the PA6 matrix. The combination of good interface adhesion, excellent orientation, and high crystallinity of the matrix leads to efficient phonon propagation, resulting in a significant improvement in the thermal conductivity of the composite. The highest thermal conductivity of the composite is achieved when the SA content is 5 phr, which is 3.59 W m−1K−1. The utilization of a composite material consisting of 5phr SA as the thermal interface material displays the highest thermal conductivity, and the composite also demonstrates satisfactory mechanical properties. This study proposes a promising strategy for the preparation of composites with high thermal conductivity.Keywords:thermal conductivity;polyamide;boron nitride;stearic acid
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Shufen Wang,Jinrou Wei,Hongzhao Xie,Xiaopeng Chen,Jie zhen Liang,Xiaojie Wei,Jie Huang,Linlin Wang
The phase equilibrium relationships of resin systems are indispensable for resin tapping, distillation, and investigating the release of terpenes in biogenic volatile organic compounds (BVOCs). Herein, we obtained the vapor–liquid equilibrium (VLE) data of monoterpene-sesquiterpene systems that contain resin acid by a headspace gas chromatography (HS-GC). There is no azeotropic behavior between terpenes, and abietic acid was found to inhibit the volatilization and separation of terpenes. Furthermore, the saturated vapor pressure of the systems almost triples when the experimental temperature increases from 313.15 to 333.15 K, which may exacerbate terpene emissions in ecosystems. Additionally, the thermodynamic consistency of the VLE values was confirmed by van Ness test, and the experimental data were correlated using NRTL, UNIQUAC, and Wilson activity coefficient models, while the Conductor-like Screening Model for Real Solvents (COSMO-RS) model was utilized for predictions. All of the data satisfy thermodynamic consistency, and the correlation results and prediction results demonstrate good adherence of the activity coefficient models to experimental values and the positive capacity of COSMO-RS in predicting the VLE relationship for the pine resin systems, respectively.
研究领域:
生态学
·
化学工程
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Xiang Liu,Tian C. Zhang,Huaqiang He,Like Ouyang,Shaojun Yuan
Corrosion is one of the most challenging issues for the large-scale application of magnesium alloys . Fabricating a superhydrophobic surface with a low-cost, easy-to-handle method is meaningful for anti-corrosion protection of Mg alloys. In this study, a stearic acid/CeO 2 bilayer coating was prepared on AZ31B Mg by a simple electrodeposition method combined with immersion in stearic acid solution. The growth traits of the coating with different electrodeposition current densities and time were evaluated, which demonstrated that 60 min combined with 0.65 mA/cm 2 is the optimal electrodeposition condition. Besides, the wettability , anti-corrosion ability, durability, chemical stability and self-cleaning properties of the coating were comprehensively investigated. The results showed that the as-prepared coating exhibited a good superhydrophobic and self-cleaning property with CA>158° and SA<2°. Moreover, the coating demonstrated an improved anti-corrosion performance in 3.5 wt% NaCl solution and was quite stable in the atmosphere and in contact with pH droplets of 1–13.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
Polymer-Plastics Technology and Materials
·
2022
·
IF 2.439
Weihua Ye,Zhi Wen,Chao Chen,Minyan Zhang,Zhengfu Liao
Poly(vinyl chloride) (PVC) has been widely used in many fields due to its excellent comprehensive properties, although its thermal stability is poor. In the article, a urea derivative, cyanoacetylurea, is prepared and its structure is characterized by means of FTIR and 1H-NMR. The stabilization effect of cyanoacetylurea on PVC thermal stabilization is evaluated by thermogravimetric analysis (TGA), thermal aging test and Congo red test. Meanwhile, the processability of PVC stabilized by cyanoacetylurea is investigated through dynamic performance test. Compared with calcium stearate (CaSt2) and zinc stearate (ZnSt2), cyanoacetylurea shows higher stabilization effect on PVC thermal stabilization than CaSt2 and ZnSt2. Also, the synergistic effect of mixtures of cyanoacetylurea, CaSt2 and ZnSt2 on PVC thermal stabilization is investigated. At last, the stabilization mechanism is discussed and cyanoacetylurea is able to absorb hydrogen chloride and to add hydrogen chloride on the carbonyl group, as well as postpone “zinc burning.” The results show that cyanoacetylurea presents a good thermal stabilization efficiency and can be a potential organic thermal stabilizer for PVC.
研究领域:
材料科学
·
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 24
·4156
·
IF 4.7
Cunshe Chen,Sihan Zheng,Zexun An,Zhihua Pang,Xinqi Liu
This study investigates the oral processing characteristics and application of soybean fiber and sodium alginate microgel in enhancing the texture and sensory attributes of low-fat yogurt. By combining soybean fiber with sodium alginate, a stable composite microgel system was developed with a uniform particle-size distribution. Oral lubrication performance was assessed by evaluating particle size, texture, friction coefficient and rheological properties, providing insights into how microgels improve food lubricity. The results showed that adding soybean fiber/sodium alginate microgel to low-fat yogurt significantly enhanced lubrication, texture and sensory quality compared to standard low-fat yogurt. The yogurt sample containing 2 wt% microgel achieved optimal sensory results, improving hardness and adhesiveness. This study suggests that soybean fiber/sodium alginate microgel offer a promising strategy for enhancing the sensory quality in low-fat dairy products, supporting healthier food innovations.
研究领域:
食品科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）