L. N. Studenikina, A. V. Protasov, D. A. Borzenkov, A. A. Melnikov, S. Y. Domareva
{"title":"水溶液中臭氧氧化法改性聚乙烯醇","authors":"L. N. Studenikina, A. V. Protasov, D. A. Borzenkov, A. A. Melnikov, S. Y. Domareva","doi":"10.20914/2310-1202-2022-4-192-199","DOIUrl":null,"url":null,"abstract":"Currently, the task of obtaining polyvinyl alcohol oligomers (PVA) is urgent to create functional materials of a new generation with specified properties. One of the methods of modification of PVS is ozonolysis, which has a number of advantages over other methods of oxidative degradation of polymers. The aim of the work is to evaluate the structural changes and physico–mechanical characteristics of film samples of PVS modified by ozonated oxidation. To carry out the oxidation process, a 5% aqueous solution of PVA brand 1799 was prepared. The ozone-oxygen mixture was obtained using an ozonizer of a known design. The oxidation of PVS was carried out in a glass thermostatically controlled flask at 70 ° C, blowing an ozone-oxygen mixture through an aqueous solution of PVS for 40 minutes. Sampling was carried out after 10, 20 and 40 minutes of oxidation. The films were obtained by irrigation followed by air drying, after which they were subjected to IR spectrometric analysis and strength indicators were determined. As a result of the study, it was found that the modification of PVA brand 1799 by ozonated oxidation in an aqueous medium is accompanied by the following change in IR spectrograms: in the region of 1400 - 1600 cm-1, a sharp decrease in the intensity of the peak corresponding to hydroxyl groups forming hydrogen bonds is observed for ozone-oxidized PVA, in the region of 1650 – 1700 cm-1, a pattern of decrease in intensity is noted the peak with an increase in the oxidation time of PVA with ozone, which indicates a decrease in the MM of the polymer as a result of oxidative degradation, in the region of 3400 – 3600 cm-1 marked a change in the nature of the spectrogram, which also indicates a change in the structure of hydrogen bonds in oxidized PVS; the physico-mechanical properties of film samples subjected to 40-minute ozonated oxidation of PVS change towards a decrease in both strength and elongation at break by an average of 4 times, the Young's modulus decreases by more than 3 times, and the stretching diagram changes character in the zone of highly elastic deformation (the intensity of stress growth decreases by 1.5-2 times as the film elongates during stretching) and the fracture zone (the diagram acquires a stepwise character without a sharp break), which is associated with a decrease in the molecular weight of the PVS, the acquisition of new functional groups, a change in the stereoregularity of the hydroxyl groups of the main polymer chains, an increase in amorphousness and a change in their relaxation time.","PeriodicalId":31207,"journal":{"name":"Vestnik Voronezskogo Gosudarstvennogo Universiteta Inzenernyh Tehnologij","volume":"168 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Modification of polyvinyl alcohol by ozonated oxidation in an aqueous solution\",\"authors\":\"L. 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Sampling was carried out after 10, 20 and 40 minutes of oxidation. The films were obtained by irrigation followed by air drying, after which they were subjected to IR spectrometric analysis and strength indicators were determined. 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引用次数: 0
摘要
目前,制备具有特定性能的新一代功能材料迫切需要获得聚乙烯醇低聚物(PVA)。臭氧分解是改性PVS的方法之一,与其他聚合物氧化降解方法相比,臭氧分解具有许多优点。本研究的目的是评价臭氧氧化修饰的PVS薄膜样品的结构变化和物理力学特性。为了进行氧化过程,制备了5% PVA 1799的水溶液。使用已知设计的臭氧发生器获得臭氧-氧气混合物。PVS的氧化在70°C的玻璃恒温烧瓶中进行,将臭氧-氧气混合物吹过PVS水溶液40分钟。在氧化10、20和40分钟后取样。经冲洗、风干得到薄膜,对薄膜进行红外光谱分析并测定其强度指标。研究结果发现,在水介质中臭氧氧化对PVA 1799牌号进行改性后,其红外光谱图出现如下变化:在该地区1400 - 1600 cm - 1,峰的强度急剧降低相应的羟基形成氢键ozone-oxidized PVA观察到,在该地区1650 - 1700 cm - 1,强度下降的模式指出,峰值与PVA与臭氧的氧化时间的增加,这表明MM减少聚合物的氧化降解的结果,在该地区的3400 - 3600 cm - 1标志着一个谱图的性质的变化,这也表明氧化PVS中氢键结构发生了变化;经过40分钟臭氧氧化的PVS薄膜样品的物理力学性能变化为强度和断裂伸长率平均下降4倍,杨氏模量下降3倍以上;拉伸图在高弹性变形区(拉伸过程中应力增长强度随薄膜伸长而减小1.5-2倍)和断裂区(拉伸图呈现逐步变化特征,但没有急剧断裂)发生变化,这与PVS分子量的减小、新官能团的获得、主聚合物链羟基的立体规整性的改变有关。无定形性的增加和弛豫时间的改变。
Modification of polyvinyl alcohol by ozonated oxidation in an aqueous solution
Currently, the task of obtaining polyvinyl alcohol oligomers (PVA) is urgent to create functional materials of a new generation with specified properties. One of the methods of modification of PVS is ozonolysis, which has a number of advantages over other methods of oxidative degradation of polymers. The aim of the work is to evaluate the structural changes and physico–mechanical characteristics of film samples of PVS modified by ozonated oxidation. To carry out the oxidation process, a 5% aqueous solution of PVA brand 1799 was prepared. The ozone-oxygen mixture was obtained using an ozonizer of a known design. The oxidation of PVS was carried out in a glass thermostatically controlled flask at 70 ° C, blowing an ozone-oxygen mixture through an aqueous solution of PVS for 40 minutes. Sampling was carried out after 10, 20 and 40 minutes of oxidation. The films were obtained by irrigation followed by air drying, after which they were subjected to IR spectrometric analysis and strength indicators were determined. As a result of the study, it was found that the modification of PVA brand 1799 by ozonated oxidation in an aqueous medium is accompanied by the following change in IR spectrograms: in the region of 1400 - 1600 cm-1, a sharp decrease in the intensity of the peak corresponding to hydroxyl groups forming hydrogen bonds is observed for ozone-oxidized PVA, in the region of 1650 – 1700 cm-1, a pattern of decrease in intensity is noted the peak with an increase in the oxidation time of PVA with ozone, which indicates a decrease in the MM of the polymer as a result of oxidative degradation, in the region of 3400 – 3600 cm-1 marked a change in the nature of the spectrogram, which also indicates a change in the structure of hydrogen bonds in oxidized PVS; the physico-mechanical properties of film samples subjected to 40-minute ozonated oxidation of PVS change towards a decrease in both strength and elongation at break by an average of 4 times, the Young's modulus decreases by more than 3 times, and the stretching diagram changes character in the zone of highly elastic deformation (the intensity of stress growth decreases by 1.5-2 times as the film elongates during stretching) and the fracture zone (the diagram acquires a stepwise character without a sharp break), which is associated with a decrease in the molecular weight of the PVS, the acquisition of new functional groups, a change in the stereoregularity of the hydroxyl groups of the main polymer chains, an increase in amorphousness and a change in their relaxation time.