Effect of Orotic Acid on the Stabilization Efficiency of Ca-Zn Thermal Stabilizers for Poly(vinyl chloride)

2015 ◽  
Vol 815 ◽  
pp. 545-550
Author(s):  
Xiao Peng Xu ◽  
Si Chen ◽  
Yan Qin Shi ◽  
Bo Zhen Wu ◽  
Meng Ma ◽  
...  
Keyword(s):  
Orotic Acid ◽  
Synergistic Effects ◽  
Zinc Stearate ◽  
Long Term Stability ◽  
Poly Vinyl Chloride ◽  
Stabilization Effect ◽  
Initial Color ◽  
Catalytic Effects ◽  
Thermal Stability Of

The effect of orotic acid (OA) and its mixtures with calcium stearate (CaSt2) and zinc stearate (ZnSt2) in various ratios on the thermal stability of PVC has been investigated by Congo red and discoloration tests. The results shows that OA acts as a long-term thermal stabilizer for PVC like CaSt2, and the combination of OA and ZnSt2 exhibited a synergistic stabilization effect at a certain ratio. This is due to the ability of OA to absorb HCl released during the degradation of PVC to diminish its catalytic effects, and react with ZnCl2 to stop its catalytic effect for PVC. CaSt2-ZnSt2/OA stabilizers exhibit good synergistic effects with both acceptable initial color and long-term stability for PVC

scholarly journals Synthesis and Study of Zinc Orotate and its Synergistic Effect with Commercial Stabilizers for Stabilizing Poly(Vinyl Chloride)

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 194 ◽  
Author(s):  
Feng Ye ◽  
Qiufeng Ye ◽  
Haihua Zhan ◽  
Yeqian Ge ◽  
Xiaotao Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Synergistic Effect ◽  
Vinyl Chloride ◽  
Zinc Stearate ◽  
Precipitation Method ◽  
Long Term Stability ◽  
Poly Vinyl Chloride ◽  
Initial Color ◽  
Thermal Stability Of

Zinc orotate (ZnOr2), which is a new kind of poly(vinyl chloride) (PVC) stabilizer, is prepared in this work through the precipitation method, and its impact on the thermal stability of PVC is measured by thermogravimetric analysis (TG), Congo red test, and discoloration test. The results exhibit that the thermal stability of PVC is positively enhanced after the addition of ZnOr2. In contrast with a commercial thermal stabilizer, zinc stearate (ZnSt2), a noteworthy improvement was observed that ZnOr2 could postpone the “zinc burning” of PVC. This is principally ascribed to the Or anion in the structure of ZnOr2 being able to absorb the HCl released by PVC, and to supersede unstable chlorine atoms in the structure of PVC. In addition, blending ZnOr2 with calcium stearate (CaSt2) in diverse mass ratios can significantly accelerate the thermal stability of PVC. Optimum performance was achieved with a CaSt2:ZnOr2 ratio of 1.8:1.2. Moreover, an outstanding synergistic effect can be observed when CaSt2/ZnOr2 is coupled with other commercial auxiliary stabilizers. The initial color and long-term stability of PVC including CaSt2/ZnOr2 is significantly increased when pentaerythritol (PER) is added, while dibenzoylmethane (DBM) can only improve its long-term thermal stability.

scholarly journals On Long-Term Stability of Metallic Glasses

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1076 ◽  
Author(s):  
Louzguine-Luzgin ◽  
Jiang
Keyword(s):  
Metallic Glasses ◽  
Surface Oxidation ◽  
Initial Structure ◽  
Ambient Conditions ◽  
Scanning Calorimetry ◽  
Long Term Stability ◽  
Transmission Electron ◽  
Different Types ◽  
Thermal Stability Of

Thermal stability of different types of metallic glasses and partially crystalline alloys stored for at least 15 years at ambient conditions was tested in the present work by differential scanning calorimetry in comparison with that of the original alloys tested in the as-cast state in the earlier works. The structure of the naturally aged alloys was also studied by X-ray diffractometry. The structure of a couple of selected alloys was also tested by transmission electron microscopy. Most of the alloys retained their initial structure and showed only a moderate decrease in the crystallization temperature. Only those alloys which showed visible surface oxidation (Cu-Zr-system based) were partly transformed into a crystalline state forming micron-scale Cu particles in air at ambient conditions.

scholarly journals Flower-Like MoSe2/MoO2 Composite with High Capacity and Long-Term Stability for Lithium-Ion Battery

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1256 ◽  
Author(s):  
Qiuyan Hao ◽  
Guoliang Cui ◽  
Yan Zhao ◽  
Zhumabay Bakenov
Keyword(s):  
High Performance ◽  
Synergistic Effects ◽  
High Capacity ◽  
Lithium Ion ◽  
Active Surface ◽  
Interlayer Spacing ◽  
Simple Method ◽  
Long Term Stability ◽  
Specific Discharge

A simple method is developed for the preparation of MoSe2/MoO2 composite with a flower-like structure for high-performance lithium-ion batteries (LIBs). MoSe2 could lead to fast and facile movement of Li+ due to its larger interlayer spacing. Meanwhile, MoO2 could protect the lamellar structure of MoSe2 from being destroyed in the charging/discharging processes to maintain the required active surface to electrolytes. In addition, the flower-like structure of the composite could effectively alleviate the volume expansion during charging/discharging. As LIBs are anode material, MoSe2/MoO2 composite demonstrates an excellent specific discharge capacity of 1042 mAh g−1 after 100 cycles at 0.1 A g−1, which is attributed to the synergistic effects of MoSe2 and MoO2 in the composite.

scholarly journals Enhancing the thermal stability of the carbon-based perovskite solar cells by using a CsxFA1−xPbBrxI3−x light absorber

RSC Advances ◽  
2019 ◽  
Vol 9 (21) ◽  
pp. 11877-11881 ◽  
Author(s):  
Pengfei Wang ◽  
Nianyao Chai ◽  
Chang Wang ◽  
Jingchen Hua ◽  
Fuzhi Huang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solar Cells ◽  
Thermal Cycling ◽  
Perovskite Solar Cells ◽  
Constant Heat ◽  
Long Term Stability ◽  
Light Absorber ◽  
Thermal Stability Of ◽  
Carbon Based

Mixed-cation CsxFA1–xPbBrxI3–x perovskite was used as light absorber for the carbon-based perovskite solar cells, and the as-prepared solar devices showed excellent long-term stability under constant heat (85 °C) and thermal cycling (−30 °C to 85 °C) condition.

MoS2–MoP heterostructured nanosheets on polymer-derived carbon as an electrocatalyst for hydrogen evolution reaction

2018 ◽  
Vol 6 (2) ◽  
pp. 616-622 ◽  
Author(s):  
Zexing Wu ◽  
Jie Wang ◽  
Kedong Xia ◽  
Wen Lei ◽  
Xien Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Acid Medium ◽  
Hydrogen Evolution Reaction ◽  
Electrocatalytic Activity ◽  
Synergistic Effects ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Electronic Interactions ◽  
Long Term Stability

MoS2–MoP/C prepared through a facile and scalable strategy exhibited excellent electrocatalytic activity and long-term stability for HER in acid medium. The electronic interactions, relative high specific surface area and synergistic effects of the doped heteroatoms contribute to the superior catalytic performance.

scholarly journals Development and Investigation of Lanthanum Sulfadiazine with Calcium Stearate and Epoxidised Soyabean Oil as Complex Thermal Stabilizers for Stabilizing Poly(vinyl chloride)

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 531 ◽  
Author(s):  
Qiufeng Ye ◽  
Xiaotao Ma ◽  
Bobin Li ◽  
Zhe Jin ◽  
Yingying Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Vinyl Chloride ◽  
Calcium Stearate ◽  
Gravimetric Analysis ◽  
Thermal Stabilizer ◽  
Poly Vinyl Chloride ◽  
Water As Solvent ◽  
Vis Spectroscopy ◽  
Thermal Stability Of

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 CaSt2 can provide outstanding improvement in the long-term thermal stability of PVC. When the ratio of LaSD/ESBO/CaSt2 is 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.

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