عنوان

ویژگی های فیزیکوشیمیایی بیونانوکامپوزیت کربوکسی متیل سلولز حاوی نانورس و نانوکریستال سلولز

‭۱۷۵پ‬

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ویژگی های فیزیکوشیمیایی بیونانوکامپوزیت کربوکسی متیل سلولز حاوی نانورس و نانوکریستال سلولز

/لیلا ابوالقاسمی فخری

تبریز:دانشگاه تبریز،دانشکده کشاورزی ، گروه صنایع غذایی

‮‭۱۴۷‬ص‬

جدول،نمودار،عکس

چاپی

واژه نامه

کتابنامه ص.: ‮‭۱۳۹-۱۴۷‬

کارشناسی ارشد

مهندسی کشاورزی-صنایع غذایی

‮‭۱۳۸۹/۱۱/۱۷‬

تبریز:دانشگاه تبریز،دانشکده کشاورزی ، گروه صنایع غذایی

.Today, dozens of different synthetic plastics, totaling about 200 million tons per year, are produced throughout the world. Among them, packaging is the largest single market for plastics. Though the synthetic petrochemical-based polymers have been widely used in a variety of packaging materials, they become a major source of waste after use due to their poor biodegradability. The environmental impact of persistent plastic wastes is raising general global concern, and disposal methods are limited. Incineration may generate toxic air pollution, satisfactory landfill sites are limited, and recycling methods for commingled waste are expensive and often energy-intensive. In addition, petroleum resources are finite and are becoming limited. Then, the use of renewable resources to produce edible or biodegradable packaging materials that can maintain product quality and reduce waste disposal problems are being explored. Carboxymethyl cellulose (CMC), is a very unique material in many of these respects: It forms strong and clear films; and it has the potential for excellent material properties by combination with appropriate fillers. Moreover it is a relatively low cost, renewable, and abundant resource. Nevertheless, CMC exhibits several disadvantages compared to conventional synthetic polymers. It has strong hydrophilic character (water sensitivity) and poor mechanical and thermal properties such as other polysaccharides, which make it unsatisfactory for some applications such as packaging purposes. Generally, many approaches are suggested to mitigate these shortcomings in biopolymer films. One approach is to blend biopolymers with synthetic polymers. Because of solubility by water, no toxicity, and biodegradation by microorganisms, PVOH which is an excellent biodegradable polymer has been increasingly used as packing materials. Development of the polymer-clay nanocomposites is one of the latest revolutionary steps of the polymer technology. The addition of low percentages of clay to polymers may cause to increase mechanical strength; improve barrier against moisture, oxygen, carbon dioxide and improve other properties of polymers and biopolymers. During the past decade, many attempts have been reported to mimic natural bionanocomposites by blending polysaccharide nanocrystals from different sources with polymeric matrix. The good mechanical and thermal properties, and other properties of cellulose nanocrystals such as low density, biodegradability, and availability from renewable resources, cause to have the ability to significantly reinforce thermoplastic polymers at low filler loadings. In this study, novel Environmentlly-friendlly carboxymethyl Cellulose (CMC)-Poly Vinyl Alcohol (PVOH) -Montmorillonite (MMT) and CMC-PVOH-Cellulose nanowhisker (CNW) nanocomposite films were successfully prepared by casting method. CMC-PVOH-Cellulose nanowhisker (CNW) nanocomposite films were prepared using a colloidal aqueous suspension of cellulose whiskers. The cellulose whiskers, prepared from cotton linter by hydrolyzing with sulfuric acid aqueous solution consisted of slender rods with an average length of 240 nm and diameter of 13 nm, respectively. The effect of PVOH, MMT, and CNW on the functional properties of these bionanocomposites was studied. Results show that the incorporating of 10 wt PVOH in to CMC matrix, improve the moisture resistance, water vapor permeability (WVP), mechanical and thermal properties and increased surface hydrophobicity of CMC film. Structural studies by XRD and AFM analysis confirmed the good and uniform dispersion of nanoclay layers and cellulose nanowhiskers in CMC-PVOH matrix. Resulted bionanocomposite films, exhibited significant improvement in barrier, mechanical and thermal properties

ابوالقاسمی فخری، لیلا

Carboxymethyl cellulose

قنبرزاده، بابک، استاد راهنما

دهقان نیا، جلال، استاد راهنما

انتظامی، علی اکبر، استاد مشاور

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