{"title":"Mechanochemical Preparation of Poly(vinyl alcohol)/Carboxymethyl Cellulose Composites","authors":"O. N. Dabizha, O. A. Shilova, E. M. Ivan’kova","doi":"10.1134/s1061933x23601312","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Biodegradable solid-phase poly(vinyl alcohol)/carboxymethyl cellulose composites, which are promising to be used in pharmaceutics, agriculture, and chemical industry, have been obtained by an environmentally friendly method of “mild” mechanochemical activation without solvents and crosslinking agents. Air-dry mixtures of poly(vinyl alcohol) and carboxymethyl cellulose taken in mass ratios of 2 : 1, 1 : 1, and 1 : 2 have been subjected to a shock–shear action for 3 and 5 min (mechanical energy doses of 0.74 and 1.24 kJ/g) using an IVS-4 vibrating grinder (1500 rpm; 23.4 Hz; 0.55 kW; sample weight, 50 g; grinding bodies-to-sample mass ratio, 44 : 1). The mechanically activated samples in the form of medium powders (bulk density within a range of 600–1000 kg/m<sup>3</sup>) have been studied by the methods of scanning electron microscopy, differential scanning calorimetry, thermogravimetry, IR spectroscopy, optical microscopy, pycnometry, turbidimetry, and gravimetry. It has been found that the mechanochemical activation of an equimass mixture of poly(vinyl alcohol) and carboxymethyl cellulose at a mechanical energy dose of 1.24 kJ/g yields polymer solutions with a concentration of 1 g/dL that are rather transparent in the visible region (turbidity of 0.14 cm<sup>–1</sup>) and stable for 96 h. It has been revealed that, when being dried at 25°C, poly(vinyl alcohol) crystallizes from aqueous 1 and 2 g/dL solutions to form dendrites or crystallites after treatment at mechanical energy doses of 0.74 and 1.24 kJ/g, respectively. Polymer films of the composites have a complex morphology that includes dendritic and axialite crystalline forms. It has been found that the mechanochemical treatment stimulates the formation of crystalline forms of polymers, changes their intermolecular interaction, and affects the hydroxyl and ether groups of carboxymethyl cellulose, as well as the hydroxyl groups of poly(vinyl alcohol).</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Colloid Journal","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1134/s1061933x23601312","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Biodegradable solid-phase poly(vinyl alcohol)/carboxymethyl cellulose composites, which are promising to be used in pharmaceutics, agriculture, and chemical industry, have been obtained by an environmentally friendly method of “mild” mechanochemical activation without solvents and crosslinking agents. Air-dry mixtures of poly(vinyl alcohol) and carboxymethyl cellulose taken in mass ratios of 2 : 1, 1 : 1, and 1 : 2 have been subjected to a shock–shear action for 3 and 5 min (mechanical energy doses of 0.74 and 1.24 kJ/g) using an IVS-4 vibrating grinder (1500 rpm; 23.4 Hz; 0.55 kW; sample weight, 50 g; grinding bodies-to-sample mass ratio, 44 : 1). The mechanically activated samples in the form of medium powders (bulk density within a range of 600–1000 kg/m3) have been studied by the methods of scanning electron microscopy, differential scanning calorimetry, thermogravimetry, IR spectroscopy, optical microscopy, pycnometry, turbidimetry, and gravimetry. It has been found that the mechanochemical activation of an equimass mixture of poly(vinyl alcohol) and carboxymethyl cellulose at a mechanical energy dose of 1.24 kJ/g yields polymer solutions with a concentration of 1 g/dL that are rather transparent in the visible region (turbidity of 0.14 cm–1) and stable for 96 h. It has been revealed that, when being dried at 25°C, poly(vinyl alcohol) crystallizes from aqueous 1 and 2 g/dL solutions to form dendrites or crystallites after treatment at mechanical energy doses of 0.74 and 1.24 kJ/g, respectively. Polymer films of the composites have a complex morphology that includes dendritic and axialite crystalline forms. It has been found that the mechanochemical treatment stimulates the formation of crystalline forms of polymers, changes their intermolecular interaction, and affects the hydroxyl and ether groups of carboxymethyl cellulose, as well as the hydroxyl groups of poly(vinyl alcohol).
期刊介绍：
Colloid Journal (Kolloidnyi Zhurnal) is the only journal in Russia that publishes the results of research in the area of chemical science dealing with the disperse state of matter and surface phenomena in disperse systems. The journal covers experimental and theoretical works on a great variety of colloid and surface phenomena: the structure and properties of interfaces; adsorption phenomena and structure of adsorption layers of surfactants; capillary phenomena; wetting films; wetting and spreading; and detergency. The formation of colloid systems, their molecular-kinetic and optical properties, surface forces, interaction of colloidal particles, stabilization, and criteria of stability loss of different disperse systems (lyosols and aerosols, suspensions, emulsions, foams, and micellar systems) are also topics of the journal. Colloid Journal also includes the phenomena of electro- and diffusiophoresis, electro- and thermoosmosis, and capillary and reverse osmosis, i.e., phenomena dealing with the existence of diffusion layers of molecules and ions in the vicinity of the interface.
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