POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Feng Ye,Xiaojie Guo,Haihua Zhan,Jiaxian Lin,Weichong Lou,Xiaotao Ma,Xu Wang
Zinc urate (Zn 3 Ur 2 ) is synthesized by the reaction of uric acid and zinc acetate , and the structure of the complex is confirmed by Elemental analysis (EA), Thermogravimetric analysis (TGA) and Infrared spectroscopy (FTIR). The thermal stability effect of Zn 3 Ur 2 with its assistant thermal stabilizers about calcium stearate, β-diketones and polyols on Poly (vinyl chloride) (PVC) is investigated by TG, Congo red test and Discoloration test. The results show that the thermal stability of PVC is increased significantly after Zn 3 Ur 2 is added. Compared with traditional commercial thermal stabilizer such as ZnSt 2 , Zn 3 Ur 2 can observably delay the “Zinc burning” of PVC and the complete discoloration time is improved to 150 min. This is mainly attributed to the anions in the structure of Zn 3 Ur 2 , which could efficiently absorb the HCl released by PVC and have ability to replace unstable chlorine atoms on structure of PVC. Moreover, the mixing of Zn 3 Ur 2 and calcium stearate (CaSt 2 ) can signally promote the long-term thermal stability of PVC. The thermal stability of PVC reaches the optimal state when the ratio of CaSt 2 /Zn 3 Ur 2 is 1.8/1.2 and its total black time arrives at 210 min. In addition, an excellent synergistic effect can be observed when CaSt 2 /Zn 3 Ur 2 is combined with other commercial assistant stabilizers. The initial color and long-term stability of PVC containing CaSt 2 /Zn 3 Ur 2 is markedly improved when Dibenzoylmethane (DBM) is added while Pentaerythritol (PER) can only increase its long-term stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 3
·531
·
IF 3.164
Qiufeng Ye,Xiaotao Ma,Bobin Li,Zhe Jin,Yingying Xu,Cheng Fang,Xiaoya Zhou,Yeqian Ge,Feng Ye
Lanthanum sulfadiazine (LaSD) was synthesized from sulfadiazine and lanthanum nitrate using water as solvent under alkaline conditions, and was used as a novel rare earth thermal stabilizer to stabilize poly(vinyl chloride) (PVC). The structure of LaSD was characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR) and thermo- gravimetric analysis (TGA). The influence of lanthanum sulfadiazine with calcium stearate (CaSt2) and epoxidized soybean oil (ESBO) on stabilizing PVC was studied by using the Congo red test, oven discoloration test, UV-vis spectroscopy and thermal decomposition kinetics. The results showed that the addition of LaSD as a thermal stabilizer can significantly improve the initial whiteness and long-term stability of PVC. In addition, the synergies between LaSD, ESBO, and CaSt2can provide outstanding improvement in the long-term thermal stability of PVC. When the ratio of LaSD/ESBO/CaSt2is 1.8/0.6/0.6, its thermal stability time is 2193 s which is the best state for stabilizing PVC. Furthermore, comparing the reaction energy (Ea) and the variations in the conjugate double bond concentration in PVC samples, the order of thermal stability of PVC was PVC/LaSD/ESBO/CaSt2> PVC/LaSD/ESBO > PVC/LaSD. The thermal stability mechanism of LaSD on PVC was studied by the AgCl precipitation method and FTIR spectrum. The results showed that the action of LaSD on PVC was achieved through replacing unstable chlorine atoms and absorbing hydrogen chloride.Keywords:lanthanum sulfadiazine;poly(vinyl chloride);calcium stearate;epoxidised soya bean oil;synergistic effect;thermal decomposition kinetics
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2022
·Vol. 29
·期 10
·1-13
·
IF 3.061
Liu Zhipeng,Du Yue,Li Jiangshan,Kang Da,Ye Chunlin,Zhao Shicheng
The flowability of Ultra-high molecular weight polyethylene (UHMWPE) is very poor so flow modification is needed to improve its processing efficiency, but flow modification could significantly deteriorate its wear resistance. To solve this technical problem, it is necessary to recognize the reasons why flow modifiers deteriorate the wear resistance of UHMWPE. In current research, influence of calcium stearate (CaSt) which is a commonly used flow modifier on the wear resistance of UHMWPE was investigated, the experimental results showed that a small amount of CaSt (0.5wt%) could significantly deteriorate the wear resistance of UHMWPE (11%). Subsequently, the effect of CaSt on the three-phase structure (amorphous, crystalline and interphase) of UHMWPE was investigated to explain why CaSt deteriorates the wear resistance of UHMWPE in terms of structure–property relationship. The study of crystallization and melting behavior indicates that the incorporation of CaSt makes the matrix produce more well-formed crystals thus increasing the hardness of the matrix, and the increase in hardness can alleviate the degree of abrasive wear. The study of the amorphous region found that CaSt has a unique disentanglement effect, which reduces the degree of entanglement of molecular chains of the matrix, and the reduction of the degree of entanglement deteriorates the shear resistance of the matrix, thus aggravating the shear damage of the sample during the wear process. Meanwhile, the disentanglement effect of CaSt can also improve the recrystallization ability of the matrix, reducing the interphase of the matrix thus making the matrix more susceptible to structural damage during the wear process. Furthermore, the incorporation of CaSt significantly reduces the heat resistance of the matrix, which makes the wear resistance of the matrix deteriorate more caused by the friction heat during the wear process. This paper can provide theoretical guidance to solve the problem of severe degradation of wear resistance after flow modification of UHMWPE and provide inspiration for the structural design of other wear-resistant materials.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2024
·Vol. 26
·期 13
·2400481
·
IF 3.4
Mingjie Wu,Liang Shao,Chunyan Ma,Yinkun He,Yanlong Yang,Wenqi Wang,Jianzhong Ma,Zhanyou Ji
Thermoplastic polyurethane (TPU) elastomer is a commonly used material for foam preparation. However, its application is hindered by significant shrinkage behavior. To reduce the foam shrinkage, polylactic acid (PLA) and calcium stearate-modified montmorillonite (MMT-St) are incorporated into the polyurethane matrix. The TPU/PLA/MMT-St composite foams are formed using an intermittent supercritical carbon-dioxide-foaming process. The addition of PLA inhibits the relaxation of TPU chain segments, while the introduction of calcium stearate (GaSt 2 ) improves the dispersion of MMT within the matrix, increases the nucleation sites of cell growth, and improves cell structure. The cell diameter decreases from 10 to 4 μm, while the cell density increased from 4.1 × 10 12 to 15.8 × 10 12 cell cm −3 . In addition, the cell distribution range narrows from 4–19 to 2–6 μm. Incorporating MMT-St increases the crystallinity and thermal stability of TPU/PLA, mitigates chain relaxation at room temperature, and enhances foam dimensional stability. As a result, this leads to a decrease in shrinkage rate from 27.5% to 5%. As both matrices of the material are thermoplastic, this composite foam possesses recyclability with enhanced material utilization.
研究领域:
材料科学
·
高分子化学
✓ 已验证
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
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Yuhan Wang,Qingyuan Xu,Bao Lu,Jinfeng Sun,Zhonglun Zhang,Chuanlin Hu,Guihua Hou
In the preparation of foam concrete (FC), reconciling the contradiction of porosity (or thermal conductivity) and mechanical strength poses a significant challenge. In this paper, the strategy of regulating the carbonation of γ-2CaO·SiO 2 (γ-C 2 S) to form aragonite whiskers for strengthening the pore wall was proposed, thereby achieving the highest possible total porosity while meeting the required compressive strength. The controlled formation of aragonite and its strengthening mechanism of pore wall, as well as the optimum preparation conditions of FC formed by γ-C 2 S carbonation were studied. The results indicated that the CaCO 3 in the pore walls predominantly existed in the form of whisker-like aragonite under the action of modifier MgCl 2 ·6H 2 O, and the mass content of aragonite achieved 53.4 %, almost without calcite. Under the optimum preparation conditions, the thermal conductivity and compressive strength of aragonite foam concrete (AFC) were 0.0496 W/m·K and 0.5 MPa, respectively. Compared with calcite foam concrete (CFC) formed without the regulator, the compressive strength was increased by 150 % and the thermal conductivity was decreased by 5.2 %, it showed that thermal conductivity and mechanical strength were reconciled. Based on pore structure analysis, the formation of aragonite reduced the pore wall porosity (PP) and refined the most probable pore size. Furthermore, the CO 2 absorption rate reached 45.4 % under the carbonation of 84 h. This provides a new perspective for the preparation of low thermal conductivity FC with CO 2 sequestration functionality.
研究领域:
材料科学
·
土木工程
·
碳封存
·
晶体生长
·
隔热材料
✓ 已验证
产品关联
DOI
高影响因子
MARINE AND PETROLEUM GEOLOGY
·
2021
·
IF 4.348
Qingtao Wang,Wenhui Liu,Lixin Pei,Zhenghong Cai,Houyong Luo,Xiaofeng Wang,Dongdong Zhang,Jinzhong Liu
The total organic carbon of carbonate sediments includes a 5%–45% contribution from acid-soluble organic matter, particularly carboxylic acid salts. However, there is little information available on hydrocarbon generation from carboxylic acid salts. The objectives of this study were to investigate the extent and timing of hydrocarbon generation from calcium stearate . Thus, gold-tube nonhydrous pyrolysis experiments of calcium stearate were conducted from 250 to 600 °C at 50 MPa. Infrared spectroscopy and δ 13 C testing were also performed on solid pyrolysate and gaseous products, respectively, to trace changes of functional groups and stable carbon isotopes. Pyrolysis of calcium stearate produced hydrocarbons, CO 2 , CaO, CaCO 3 , coke, and other inorganic compounds of low molecular weight . A Van Krevelen diagram indicated that calcium stearate falls in the same region as hydrogen-rich type I kerogen. The maximum yield of methane generated from calcium stearate was as high as that from North Sea oil. Hydrocarbon generation from calcium stearate was related to cracking of the alkyl moiety and similar to that occurring in pyrolysis of n- C 18 . As a consequence of kinetic carbon isotope fractionation, with increasing temperature CO 2 becomes enriched in 13 C and CaCO 3 becomes enriched in 12 C. Notably, CaCO 3 with very low δ 13 C values is probably an effective proxy indicating hydrocarbon generation from carboxylic acid salts, if no other CaCO 3 is produced via thermochemical sulphate reduction processes. The optimized kinetic parameters demonstrate that calcium stearate had higher methane generation activation energies than those of n -C 18 and type I kerogen. Hence, methane generation from calcium stearate is delayed when extrapolated to geological conditions. This retarded methane generation illustrates the vital role of carboxylic acid salts in the generation of deep oil and gas. Future research should concern the abundance of carboxylic acid salts in carbonate formations and the depositional environments that facilitate the formation of carboxylic acid salts.
研究领域:
地质学
·
地球化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2021
·Vol. 27
·期 2
·367-375
·
IF 1.993
Zhimin Fu,Zhanhong Yang,Yao Rong,Lie Deng,Jian Wu
A high-efficiency zinc chelate stabilizer, Zn-(2-hydroxybenzylidene) aspartic acid (Zn-HBAPA), has been synthesized. From dehydrochlorination and discoloration tests conducted at 180°C, Zn-HBAPA has shown to be an excellent thermal stabilizer for flexible poly(vinyl chloride) (PVC) when compared with industrially used cadmium-zinc soap stabilizer. Blending CaSt 2 derivatives and costabilizer THAM (tris[hydroxymethyl]aminomethane) with synthesized Zn-HBAPA stabilizer in different ratios substantially improved the thermal stability of PVC while maintaining the initial color of the PVC. The thermal stability time and the induction time were 55.5 and 52 min, respectively. The initial color of PVC samples held for more than 70 min, and the time to turn the PVC samples completely black took 160 min. Results also showed that not only did the Zn-HBAPA stabilizer show a good synergistic effect when combined with CaSt 2 and THAM, but it also exhibited good compatibility with PVC.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Jianyu Wu,Zilun Tang,Xiaochun Liu,Wenjing Lin,Minghui Feng,Xiaofeng Lin,Yuxin Gu,Yong Li,Guobin Yi
Herein, as two types of rational designed thermal stabilizers, the maleic acid-sorbitol ester (MS) and zinc maleic acid-sorbitol ester complex (Zn-MS) with unsaturated carbon double bonds were synthesized to improve the initial whiteness and long-term thermal stability for polyvinyl chloride (PVC). The successfully synthesized MS and Zn-MS had three functions of replacing the labile chlorine on the PVC chains, reducing the “zinc burning” and absorbing the hydrogen chloride (HCl) released by PVC. After introducing the MS and Zn-MS, the stability time of PVC could be extended to more than 140 min and 120 min at 180 °C, respectively. Additionally, both the MS and Zn-MS had showed lower-torque effect on rheology and less-implications for plate-out in PVC. The addition of MS and Zn-MS could promote the dispersion of composition in the PVC matrix and endow the PVC with better strength and toughness. Meanwhile, in contrast with ZnSt 2 or CaSt 2 , the transparency of PVC sheet stabilized by MS and Zn-MS also showed the higher transmittance, which severally reached to 57.2% and 72.1%.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2020
·Vol. 60
·期 11
·2761-2769
·
IF 1.917
Huimin Xia,Kun Sui,Tengteng Ge,Fazong Wu,Qiqi Sun,Zhongwei Wang,Liang Song,Xiaowen Huang,Qing Yu
Punica granatum peel extractive (PPE), a novel stabilizer of polyethylene, is investigated in this study. Oxidation onset temperature (OOT), carbonyl index (CI), melt flow rate (MFR), tensile strength, and elongation at break are used to characterize the effects of PPE, which are also compared with commercial antioxidant (Irganox 1010) with the presence of tetrakis (2,4-di-tert-butylphenol)[1,1-biphenyl]-4,4′-diylbisphosphite (PEPQ). Long-term and short-term aging results show that samples modified by PPE or Irganox 1010 (PE-PPE 0.12% -P and PE-1010 0.12% -P samples) have comparable CI value and stability of OOT. However, compared with PE-PPE 0.12% -P sample, much higher CI and larger change of MFR is detected for PE-1010 0.12% -P after UV irradiation and five extrusions. It suggests that PPE is better protector for PE against UV light and mechanical shear force. All results indicate that the effect of PPE in protecting PE is comparable or much better than Irganox 1010 and it can be used as multiple stabilizers for PE. Moreover, the stabilities of PE modified with PPE alone (PE-PPE 2% ) is also investigated. Results show that PE-PPE 2% sample has good thermo-oxidative, UV and processing stabilities. All results reveal that PPE is a good candidate of PE stabilizer and it could avoid the usage of PEPQ in protecting PE.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 48
·49599
·
IF 2.52
Huimin Xia,Hui Gao,Qiqi Sun,Fazong Wu,Tengteng Ge,Kun Sui,Zhongwei Wang,Liang Song,Xiaowen Huang,Qing Yu
Puerarin, a natural compound, was used as multifunctional protector for polyethylene (PE) and polypropylene (PP). Firstly, puerarin and tetrakis(2,4-di-tert-butylphenol)[1,1-biphenyl]-4,4′-diylbisphosphite (PEPQ) could protect PE and PP against thermos-oxidative degradation: after modification, the oxidation induction time (OIT) of increased ca. 4,160% (PE-P 1200 -P sample) and 130% (PP-P 1200 -P sample); the carbonyl index (CI) obtained through accelerated aging decreased ca. 58% (PE-P 1200 -P sample). Secondly, it is excited to find that puerarin and PEPQ could pretect PE agianst photooxidative degradation: CI value decreased ca. 35% after modification. Thridly, the coorperation of puerarin and PEPQ was also benefit for the processing stability: the change of melt flow rate (MFR) between first and fifth extrusions decreased ca. 83% (PE-P 1200 -P sample) and 99% (PP-P 1200 -P sample). Forthly, puerarin and PEPQ could still protect PE against degradation after five extrusions: the loss of tensile strength and elongation at break decreased ca. 96% and 95% after modification. Finally, the interaction of puerarin with PEPQ was discussed and the role of puerarin in protecting polyolefins was proposed.
研究领域:
材料科学
·
化学工程
·
天然产物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 137
·期 2
·437-446
·
IF 2.209
Chen Si,Wang Yating,An Zhihang,Ma Meng,Shi Yanqin,Wang Xu
Amitrole is reported as a novel kind of transparent poly(vinyl chloride) (PVC) thermal stabilizer that has both excellent inhibition of “zinc burning” thermal stability and antibacterial ability in this paper, which provide the possibility of applying the whole PVC industry into medical and food packaging, artificial leather, wire and cable, indoor decoration, and so on. From the results of Congo red test, discoloration test, and dynamic thermal stability test, we could clearly find out that amitrole could effectively replace the unstable chlorine atom and inhibit “zinc burning” of transparent PVC, while the long-term stability should be improved. Next, the stabilization mechanism of amitrole was also confirmed. The antibacterial activity of amitrole was measured by the bacteriostatic ring experiments. It was observed that the PVC films had good antibacterial properties after modified by amitrole. At last, optimal design of the amitrole/ZnSt 2 (1:1)/ESBO formulation was studied, which have strong potential as thermal stabilizer to prepare super transparency and antibacterial PVC resin.
研究领域:
材料科学
·
化学工程
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）