Thermal Analysis of Acrylonitrile/Acrylic Acid Copolymer Dendrigrafted with Citric Acid

نویسنده

  • Somaye Akbari Department of Textile Engineering, Amirkabir University of Technology
چکیده مقاله:

Thermal analysis of acrylonitrile/acrylic acid P(AN/AA) copolymer films containing 5%, 10% and 20% acrylic acid dendrigrafted with citric acid (CA) is examined using differential scanning calorimetry (DSC) with various heating rates, thermogravimetry (TGA) and derivative thermogravimetric analysis (DTG). Also, the effect of carboxylic acid on thermal stabilization of the P(AN/AA) copolymers, when the carboxylic acid groups are in the bulk and when they are on the surface of the films dendrigrafted with CA, were studied using FTIR analyses. It is demonstrated that inclusion of carboxylic acid considerably enhances the rate of thermal degradation. The apparent activation energy (Ea) for overall cyclization and oxidation reactions is calculated using Kissinger’s method. The results reveal that carboxylic acid, when used as a dendrigraft, influences the cyclization and oxidation process in a different way in comparison with when they are in the bulk. The activation energy of the first generation dendrigrafted P(AN/AA) copolymer was lower than that of the copolymer and the forth dendrigraft generation.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Evaluation of hydrophilic properties of acrylonitrile/acrylic acid copolymer films dendrigrafted with citric acid

The present study investigates the hydrophilic properties of acrylonitrile/acrylic acid P(AN/AA) copolymer films with various acrylic acid (AA) contents dendrigrafted with citric acid from zero to fourth generation numbers. It was found that the hydrophilicity of the dendrigrafted films was a complicated phenomenon. Various parameters such as intermolecular hydrogen bonding, roughness and activ...

متن کامل

study of dna interaction with ethylenediaminetetraacetic acid and sesamol food additives

برهمکنش dnaتیموس گاوی طبیعی (ct-dna) با اتیلن دی آمین تترااستات (edta)در بافرtris-hcl با 8/7 ph ( دراین ph،edta به نمک دی سدیم تبدیل می شود) وسسامول در بافر tris-hcl با4/7 ph مورد بررسی قرار گرفته است. edta و سسامول استفاده فراوانی در تکنولوژی غذایی و صنعت شیمیایی دارند. مدل اتصال dna مربوط بهedta بوسیله اسپکتروفتومتری جذب، دورنگ نمایی حلقوی(cd)، ویسکومتری وژل الکتروفورز بررسی شده است. طیفuv ...

15 صفحه اول

Destructive effects of citric acid, lactic acid and acetic acid on primary enamel microhardness

  Objective: This study aimed to assess the destructive effects of citric acid, lactic acid and acetic acid produced from the fermentation of foods on primary teeth enamel.   Methods: This in vitro, experimental study was conducted on 24 sound primary teeth. The teeth were polished with a fine abrasive paper under running water. Tooth pieces measuring 3 × 4 × 3mm were cut out of the teeth and s...

متن کامل

Citric acid production.

Citric acid is a commodity chemical produced and consumed throughout The World. It is used mainly in the food and beverage industry, primarily as an acidulant. Although it is one of the oldest industrial fermentations, its World production is still in rapid increasing. Global production of citric acid in 2007 was over 1.6 million tones. Biochemistry of citric acid fermentation, various microbia...

متن کامل

Citric Acid Determination

Three types of methods have been proposed for the determination of citric acid in urine. Salant and Wise (1) used the unspecific mercuric sulfate reagent of Deniges (2) in a study of the toxicity of citrates. Thunberg (3) developed an enzymatic method employing a dehydrogenase said to be specific for citrate. The remaining methods depend on the so called pentabromoacetone method of Stahre (4), ...

متن کامل

Analysis of ascorbic acid, citric acid and benzoic acid in orange juice

Food additives, such as antioxidants and preservatives, are added to increase the shelf life of food items. In this Application Note, we describe a method to quantify an antioxidant (vitamin C) and preservatives (citric acid, benzoic acid) in orange juice. The method was developed on an Agilent 1260 Infinity LC system using an Agilent Poroshell EC-C18 column. Partial method validation was perfo...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


عنوان ژورنال

دوره 4  شماره 1

صفحات  27- 36

تاریخ انتشار 2016-03-01

با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023