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 ◽  
...  

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.

2015 ◽  
Vol 815 ◽  
pp. 545-550
Author(s):  
Xiao Peng Xu ◽  
Si Chen ◽  
Yan Qin Shi ◽  
Bo Zhen Wu ◽  
Meng Ma ◽  
...  

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


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1031 ◽  
Author(s):  
Wenyuan Han ◽  
Manqi Zhang ◽  
Degang Li ◽  
Tianbao Dong ◽  
Bing Ai ◽  
...  

Thermal stabilizers, lubricant, and plasticizers are three crucial additives for processing poly(vinyl chloride) (PVC). In this study, a new mannitol stearate ester-based aluminum alkoxide (MSE-Al) was designed and synthesized as a novel additive for PVC. The thermal stability and processing performance of PVC stabilized by MSE-Al were evaluated by the Congo red test, conductivity measurement, thermal aging test, ultravioletevisible (UV–Vis) spectroscopy test, and torque rheometer test. Results showed that the addition of MSE-Al could not only markedly improve the long-term thermal stability of PVC, but also greatly accelerate the plasticizing and decrease the balance torque, which demonstrated that MSE-Al possessed a lubricating property. Thus, MSE-Al was demonstrated to be able to provide tri-functional additive roles, e.g., thermal stabilizer, plasticizer, and lubricant. The test results for the thermal stability of PVC indicated that the initial whiteness of PVC stabilized by MSE-Al was not good enough, thus the synergistic effect of MSE-Al with zinc stearates (ZnSt2) on the thermal stability of PVC was also investigated. The results showed that there is an appreciable synergistic effect between MSE-Al and ZnSt2. The thermal stabilization mechanism and synergism effect of MSE-Al with ZnSt2 are then discussed.


Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 531 ◽  
Author(s):  
Qiufeng Ye ◽  
Xiaotao Ma ◽  
Bobin Li ◽  
Zhe Jin ◽  
Yingying Xu ◽  
...  

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.


Polymer Korea ◽  
2015 ◽  
Vol 39 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jiayou Xu ◽  
Qinghua Liang ◽  
Xiumei Xian ◽  
Kaidan Li ◽  
Jie Liu

2016 ◽  
Vol 51 (4) ◽  
pp. 261-270
Author(s):  
FK Rony ◽  
SK Ray ◽  
A Hoque ◽  
M Asaduzzaman ◽  
S Sultana ◽  
...  

Galvanizing industries of Bangladesh produce profuse amount of environmentally hazardous solid waste materials like zinc dross which contains significant amount of valuable zinc and harmful heavy lead. Zinc was extracted as zinc chloride (ZnCl2) from zinc dross. Zinc stearate (ZnSt2) samples were prepared by precipitation method from stearic acid, sodium hydroxide and ZnCl2 by varying the amount of the reagents and product yield found within the range 96.06-99.18%. Characteristic peaks of ZnSt2 were investigated by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimeter (DSC) onset curve assigned accurate melting point within the range 122.84-124.03°C. Surface morphology of ZnSt2 was observed by Scanning Electron Microscope (SEM) and products had semi-crystalline structure. Thermal stability of ZnSt2 was evaluated by Thermo-gravimetric Analyzer (TGA) that complied with literature. A combination of ZnSt2 and Calcium stearate (CaSt2) at 1:1 ratio was used as thermal stabilizer in the powder commercial grade PVC resin and performed better thermal stability. The dehydrochlorination temperature of PVC with mixed stearates was 344.67±1.04°C for 10% (w/w) loading whereas for PVC, PVC with 10% (w/w) ZnSt2 and PVC with 10% (w/w) CaSt2, it was 269.83±1.04°C, 317.33±1.26°C and 323.33±2.08°C respectively.Bangladesh J. Sci. Ind. Res. 51(4), 261-270, 2016


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