ساخت و ارزیابی ظروف سلولزی از کاه برنج با پوشش‌های طبیعی

استفاده از ضایعات کشاورزی برای تولید ظروف، یکی از گزینه‌های مناسب برای حل مشکل انباشت زیست‌توده ناشی از کشت محصولاتی همچون برنج است. به‌کارگیری کاه برنج به‌عنوان ماده اولیه ظروف سلولزی یک‌بار مصرف علاوه بر جلوگیری از ماند کاه در شالیزارها، می‌تواند موجب بهبود مشکل کمبود مواد اولیه سلولزی، کاهش استفاده از ظروف پلاستیکی و خطرات ناشی از آن شود. ساخت و ارزیابی استقامت، میزان آبگریزی و خاصیت ضدمیکروبی ظروف سلولزی تجزیه‌پذیر کاه برنج از اهداف اصلی این تحقیق می‌باشد. کاه در هاضم با سدیم هیدروکسید 10 و 20 درصد به‌منظور به‌دست آوردن ماده اولیه ساخت ظروف سلولزی، پخته و سپس برای گرفتن آزمون‌های آبگریزی، شاخص مقاومت به کشیدگی و درجه روشنایی، کاغذ با گراماژ 120 ساخته شد. غلظت‌های 1، 2، 5 و 10 درصد از محلول موماتانول به‌عنوان پوشش اولیه برای بهبود آبگریزی و عصاره گزنه ریزپوشانی شده با صمغ دانه شاهی به‌عنوان پوشش دوم برای بهبود خاصیت ضد باکتریایی استفاده شد. میزان آبدوستی و خاصیت ضد میکروبی نمونه‌ها سنجش و مقایسه گردید. قالب لیوان از فولاد دو تکه ساخته و با استفاده از خمیر مناسب کاه برنج و پوشش با غلظت مناسب نمونه ساخته شد. نتایج نشان داد افزایش مقدار سدیم‌هیدروکسید از 10 به 20 درصد در شرایط پخت موجب افزایش شاخص مقاومت به کشیدگی از 40.34 به n.m g1 43.5 و درجه روشنی از 43.41 به 45.13 می شود. افزایش سدیم هیدروکسید بر میزان آبدوستی تاثیر معنی‌داری نداشت. همچنین غلظت 5 درصد موم عسل به همراه عصاره گزنه ریزپوشانی شده با صمغ دانه شاهی با 37.22 میلی‌لیتر جذب آب و قطر هاله 4.63 میلی‌متر بهینه‌ترین پوشش به‌دست آمد.

Fabrication and Evaluation of Cellulose Containers from Rice Straw with Natural Coatings

IntroductionThe use of agricultural waste to produce biodegradable containers is an appropriate option to solve the problem of biomass accumulation resulting from the cultivation of crops such as rice. The highest amount of agricultural waste compared to the area under cultivation is related to wheat straw and rice straw, respectively. After wheat, rice is the most important agricultural product in human nutrition. According to the World Food Organization, the area under rice cultivation in the world is about 150 million hectares. The use of rice straw as a raw material for disposable cellulosic dishes can prevent straw residues in paddy fields, improve the deficiency of cellulosic raw materials, and reduce the use of plastic containers and the dangers thereof. Rice straw is a significant source for making cellulosic containers, but after making containers, hydrophobicity and microbial hazards can be among the problems of making these types of containers. The coating technique is one of the best solutions for resolving hydrophobicity and microbial problems. Coverage is very important and necessary to increase the shelf life of agricultural products and maintain their quality. Waxes are the best preventative methods against moisture and water vapor loss, and beeswax is one of the best edible waxes with these properties. The antibacterial properties of coatings with natural antioxidants will help solve the cellulose containers’ problem. The main objectives of this study were to evaluate the endurance, hydrophobicity and antimicrobial activity of rice straw degradable cellulosic dishes.Materials and MethodsIn order to obtain the raw material for the manufacture of cellulosic dishes, the straw was digested with 10% and 20% sodium hydroxide, and then to weigh the hydrophobicity tests, tensile strength index and brightness, 120 Gr paper was made. Concentrations of 1, 2, 5 and 10% of the wax solution in ethanol solution were prepared and used as the first coating to improve the hydrophobicity. The nettle extract encapsulated with royal seed gum as the second coating to improve the antibacterial activity. Hydrophobicity and antimicrobial properties of the samples were measured and compared. The cup mold specimen was made of 2piece steel and made using appropriate rice straw paste and coating with the appropriate concentration of the sample in disposable cellulose.Results and DiscussionThe results showed that increasing the amount of sodium hydroxide in baking conditions increased the tensile strength and the degree of clarity, but it had no effect on hydrophobicity. As the concentration of baking soda (sodium hydroxide) increases, so does the brightness. Increasing the concentration of sodium hydroxide increases the tensile strength, and the increase in tensile strength due to the increase in the percentage of sodium hydroxide can be due to the increase in the ability to form bonds between fibers due to the release of lignin. Honey wax with a 5% concentration was the most optimal coating for hydrophobic cellulose containers. With increasing wax concentrations in ethanol solvents from 1 to 10 percent, water absorption by the paper made from rice straw has decreased by approximately 93 percent. Adding royal seed gum and nettle extract has a positive effect on the diameter of the halo and has antimicrobial properties. Honey wax with 5% and 10% concentration with nanoencapsulated nettle extract with royal seed gum was selected as the most suitable coating to improve antibacterial activity.ConclusionDue to the characteristics of rice straw and the experiments shown, rice straw can be considered as a suitable alternative to oil resources in the production and usage of disposable tableware. Rice straw has the potential to be used as a cellulose source for the production of disposable containers, and honey wax with a 5% concentration and nanoencapsulated nettle extract can improve the hydrophobic and antimicrobial properties as the airtight coating of the dishes.