DOCSLIB.ORG

The Effect of Different Concentrations of Hydroxypropyl Methylcellulose on the Morphology

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Effect of Different Concentrations of Hydroxypropyl Methylcellulose on the Morphology The Effect of Different Concentrations of Hydroxypropyl Methylcellulose on the Morphology and Mechanical Properties of Whey Protein Isolate Edible Films Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Cyd Marie Quiñones Pérez, B.S. Graduate Program in Food Science and Technology The Ohio State University 2019 Thesis Committee Dr. Melvin Pascall, Advisor Dr. Gireesh Rajashekara Dr. Hua Wang Copyrighted by Cyd Marie Quiñones Pérez 2019 Abstract A container is a barrier between a packaged product and its external environment, and it protects the product from interaction between water, oxygen, dirt, light in some cases and microorganisms. The main types of food packaging materials are glass, plastic, metal, paper board and composites. Plastics are made from polymers. A polymer is made of a large number of monomeric units connected by covalent chemical bonds to make a large molecular weight structure. Some polymers are petroleum based while others are made from plants, animals or microorganisms. Due to increased environmental concerns about plastic waste, many researchers are currently focusing on the synthesis of bio-based sustainable plastic packaging materials. Polysaccharides such as Hydroxypropyl Methylcellulose (HPMC), and proteins such as Whey Protein Isolate (WPI) are being used in the food industry because they are widely available, nontoxic and have the capacity to produce edible films with acceptable properties. The objectives of this study were to compare the ratio of blending HPMC with WPI on physical, mechanical, thermal and permeability properties of films made with the blends. Five different blends were tested HPMC-WPI (100:0), HPMC-WPI (75:25), HPMC-WPI (50:50), HPMC-WPI (25:75) and HPMC-WPI (0:100). The impact of these blends on thickness, moisture content, water activity, homogeneity, oxygen transmission, water vapor permeability (WVP), glass transition temperature ii and morphology were determined. The results for moisture content showed that there was no significant difference between the films made with the different blends. However, HPMC-WPI (75:25) had a higher moisture content than the other blended films. The results for water activity showed that significant differences existed between some samples. The oxygen transmission analysis showed that there were no significant differences between the samples tested. HPMC- WPI (25:75) had the highest oxygen transmission rate and HPMC-WPI (50:50) had the lowest, but modifications such as increasing the relative humidity during the analysis are still necessary to confirm these results. There were no significant differences between the different permeabilities of the samples tested for water vapor permeability. The glass transition temperatures of the films shifted from 135oC to 95oC as a result of increased addition of the HPMC fraction. This indicated that the thermal transitions of the blends shifted to higher temperatures by the HPMC. The thermo- Gravimetric Analysis showed that the degradation peaks shifted to a lower temperature as the WPI concentration increased in the samples. The scanning electron micrographs of the films at different HPMC/WPI concentrations revealed homogeneously blended materials. The X-ray diffraction patterns that the blends developed higher and more intense peaks when the HPMC fraction increased. This indicated that HPMC had a higher degree of crystals when compared with WPI. This research showed that blended HPMC/WPI film could be made but more research is needed for their optimization. iii Dedication To my mom, dad and my sister, I could not have done this without you. Thank you for letting me fly. iv Acknowledgment I would like to thank Dr. Melvin Pascall for the opportunity of being part of his laboratory and for his patience during the last three years. I am grateful to the members of my committee Dr. Gireesh Rajashekara and Dr. Hua Wang for their support and advice. In addition, I would like to express my gratitude to the members of my laboratory for sharing their knowledge specially to Elliot Dhuey for his help and support in overcoming the obstacles I faced during my research. My gratitude goes to the faculty, staff and students that wake up every day with the intention of making the world a better place. My sincere thanks go to Sandy Puckett, for listening when I could barely speak. Thank you for supporting me during the lows and highs of graduate school. Thanks for creating a safe space in your office and in your heart for me. The word thank you will never be enough. I would like to thank Gabriel Fernandez Pedrosa, Paola Judith Padilla Vazquez, Evemarie Bracetti Resto and Carlos Alberto Rodríguez Santiago for simply making everything brighter. This would not have been possible without you. I thank my coworkers from The College of Nursing – Office of Student Affairs Equity and Inclusion. Thank you for being by my side during the most exciting moments and during the v most difficult ones. You have been my family, my support and my home during the last three years. You will always be in my heart and in my thoughts Finally, thank you Benedicto Quiñones Torres, Noemí Pérez Bocanegra and Hilda María Quiñones Pérez. Thank you for always understanding, for never judging, for always accepting and for letting me fly. Thank you for having faith in me, for teaching me how to be a better student, professional, and a better human. There are not enough words to describe how thankful I am. Thank you, my love. vi Vita July 1993 Born – San Juan, Puerto Rico 2016 B.S. Industrial Microbiology, University of Puerto Rico, Mayagüez Campus 2019 M.S. Food Science and Technology, The Ohio State University Field of Study Major Field: Food Science and Technology vii Table of Contents Abstract ……………………………...........…………………………………………………....... ii Dedication ………………………………………………………………………………………. iv Acknowledgment ………………………………………………………………………………... v Vita …………………………………………………………………………………………….. vii List of Tables ………………………………………………………………………………….... xi List of Figures ………………………………………………………...……………………….. xiii 1 Literature Review .................................................................................................................... 1 1.1 Packaging and it functions ............................................................................................... 1 1.2 Packaging categories ....................................................................................................... 1 1.3 Packaging materials ......................................................................................................... 2 1.3.1 Glass .................................................................................................................................................... 2 1.3.2 Metal ................................................................................................................................................... 5 1.3.3 Paper board ........................................................................................................................................ 7 1.3.4 Polymers .......................................................................................................................................... 10 1.4 Types of Edible Films ................................................................................................... 15 viii 1.4.1 Polysaccharide-based edible films and coatings .................................................................. 15 1.4.2 Protein-based edible films and coatings ................................................................................. 31 1.4.3 Lipid-based edible films and coatings ..................................................................................... 40 1.5 The methods of characterizing edible films .................................................................. 43 1.5.1 Thickness ......................................................................................................................................... 43 1.5.2 Tensile strength, elongation and elastic modulus ................................................................ 45 1.5.3 Permeability properties ................................................................................................................ 46 2 The Incorporation of Selected Small Molecule Compounds into Whey Protein Isolate – Hydroxypropyl Methylcellulose and their effect on Physical, Permeability, Thermal, Mechanical and Chemical Properties ................................................................................................................ 66 2.1 Introduction ................................................................................................................... 66 2.2 Experimental Design ..................................................................................................... 68 2.3 Materials and Methods .................................................................................................. 69 2.3.1 Preparation of HPMC-WPI at different concentrations ..................................................... 69 2.3.2 Film Moisture Content and Water Activity ........................................................................... 70 2.3.3 Oxygen Transmission Rate ......................................................................................................... 71 2.3.4 Water Vapor Permeability .........................................................................................................
Load more

Recommended publications
  • Horiba Scientific in Edi- Bottom to Top) of MCC, Sub-Hydroxypropyl Cellulose, Hypromellose (Hydroxypropyl Methylcellulose) Son, New Jersey
    ® Electronically reprinted from November 2016 Molecular Spectroscopy Workbench Characterizing Modified Celluloses Using Raman Spectroscopy Raman spectra of celluloses modified for use in the pharmaceutical, food, and materials industries are compared and analyzed, with the goal of determining spectroscopic features that can be of use in aiding in the determination of physical and chemical properties. Fran Adar ellulose is probably the most abun- the goal of then providing some insight restricted. The details of the modifications dant biopolymer on Earth and has into the chemical reactions between cel- (the chemistry of the substituent, percent C been exploited since the dawn of lulose and certain small molecules that can substitution, molecular weight, and so on) human civilization. Wood materials have change the physicochemical properties will determine the temperature of gelation been used in construction, and cotton of the reacted material. After that, we can and the viscosity of the products. Actually, and flax (linen) have been used for cloth- look at the Raman spectra of a few of these hydroxypropyl methyl cellulose (HPMC) ing and other textile applications. During modified celluloses to assess whether the is an interesting example because of the later times paper was manufactured from spectra can be useful in characterizing the variety of ways that it is used. In pharma- cellulosic sources and used for recording final products. ceutical tablets, HPMC can be used as a information. protective coating, and as a rate controlling Chemically, wood, cotton, and linen Cellulose Background release agent in timed-release formula- are all identified as cellulose, but their For the first use of cellulose in a modern tions.
    [Show full text]
  • Hydroxypropylmethyl Cellulose
    HYDROXYPROPYLMETHYL CELLULOSE Prepared at the 74th JECFA (2011) and published in FAO JECFA Monographs 11 (2011), superseding the specifications prepared at the 63rd JECFA (2004), published in the Combined Compendium of Food Additive Specifications, FAO JECFA Monographs 1 (2005). A group ADI ”not specified” for modified celluloses (ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, methyl ethyl cellulose, and sodium carboxymethyl cellulose) was established at the 35th JECFA (1989). SYNONYMS INS No. 464 DEFINITION Hydroxypropylmethyl cellulose is a methyl cellulose modified by treatment with alkali and propylene oxide by which a small number of 2-hydroxypropyl groups are attached through ether links to the anhydroglucose units of the cellulose. The article in commerce may be further specified by viscosity. Chemical names Hydroxypropylmethyl cellulose, 2-hydroxypropyl ether of methyl cellulose C.A.S. number 9004-65-3 Chemical formula [C6H7O2(OH)x(OCH3)y(OCH2CHOHCH3)z]n where z = 0.07 - 0.34 y = 1.12 - 2.03 x = 3-(z + y): (z + y = degree of substitution) Structural formula where R = H or CH3 or CH2CHOHCH3 Formula weight Unsubstituted structural unit: 162.14 Structural unit with 1.19 degree of substitution: approx. 180 Structural unit with 2.37 degree of substitution: approx. 210 Macromolecules: from about 13,000 (n about 70) up to about 200,000 (n about 1000) Assay Not less than 19% and not more than 30% of methoxy groups (-OCH3) and not less than 3% and not more than 12% hydroxypropoxy groups (-OCH2CHOHCH3), on the dried basis DESCRIPTION Hygroscopic white or off-white powder, or granules or fine fibres FUNCTIONAL USES Emulsifier, thickening agent, stabiliser CHARACTERISTICS IDENTIFICATION Solubility (Vol.
    [Show full text]
  • PHARMACOLOGY REVIEW(S) Tertiary Pharmacology Review
    CENTER FOR DRUG EVALUATION AND RESEARCH APPLICATION NUMBER: 22-210 PHARMACOLOGY REVIEW(S) Tertiary Pharmacology Review By: Paul C. Brown, Ph.D., ODE Associate Director for Pharmacology and Toxicology OND IO NDA: 22-210 Submission receipt date: December 17, 2007 Drug: Zenpep (pancrelipase) Delayed-Release Capsules Sponsor: Eurand Pharmaceuticals, Ltd. Indication: Treatment of exocrine pancreatic insufficiency due to cystic fibrosis or other conditions Reviewing Division: Division of Gastroenterology Products Introductory Comments: The pharm/tox reviewer and supervisor have found the nonclinical information adequate to support approval of this NDA for the above indication. As noted by the reviewer, no new pharmacology studies and no toxicology studies are needed for new pancreatic enzyme products as outlined in the Guidance for Industry: Exocrine Pancreatic Insufficiency Drug Products - Submitting NDAs, which was published in 2006. The sponsor submitted several studies of one of the excipients, hydroxypropyl methylcellulose phthalate. The reviewer found that the safety of the excipients was adequately supported for the indicated use. The reviewer recommended that the product be labeled as pregnancy category C and that the labeling state that animal reproduction studies have not been conducted. Conclusions: I agree that the nonclinical information provided is adequate to support approval of this NDA from a pharm/tox perspective. No additional nonclinical studies are recommended. I agree with the labeling suggestions in the pharm/tox review. 1 Submission Linked Applications Type/Number Sponsor Name Drug Name / Subject -------------------- -------------------- -------------------- ------------------------------------------ NDA 22210 ORIG 1 ZENTASE --------------------------------------------------------------------------------------------------------- This is a representation of an electronic record that was signed electronically and this page is the manifestation of the electronic signature.
    [Show full text]
  • E 460(Ii), E 461, E 462, E 463, E 464, E 465, E 466, E 468 and E 469 As Food Additives
    SCIENTIFIC OPINION ADOPTED: 27 September 2017 doi: 10.2903/j.efsa.2018.5047 Re-evaluation of celluloses E 460(i), E 460(ii), E 461, E 462, E 463, E 464, E 465, E 466, E 468 and E 469 as food additives EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Maged Younes, Peter Aggett, Fernando Aguilar, Riccardo Crebelli, Alessandro Di Domenico, Birgit Dusemund, Metka Filipic, Maria Jose Frutos, Pierre Galtier, David Gott, Ursula Gundert-Remy, Gunter Georg Kuhnle, Claude Lambre, Jean-Charles Leblanc, Inger Therese Lillegaard, Peter Moldeus, Alicja Mortensen, Agneta Oskarsson, Ivan Stankovic, Paul Tobback, Ine Waalkens-Berendsen, Matthew Wright, Alexandra Tard, Stavroula Tasiopoulou and Rudolf Antonius Woutersen Abstract Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient sources added to Food (ANS) was asked to deliver a scientific opinion on the re-evaluation of microcrystalline cellulose (E 460(i)), powdered cellulose (E 460(ii)), methyl cellulose (E 461), ethyl cellulose (E 462), hydroxypropyl cellulose (E 463), hydroxypropyl methyl cellulose (E 464), ethyl methyl cellulose (E 465), sodium carboxy methyl cellulose (E 466) and enzymatically hydrolysed carboxy methyl cellulose (E 469) as food additives. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the Scientific Committee on Food (SCF) established an acceptable daily intake (ADI) ‘not specified’ for unmodified and modified celluloses. Celluloses are not absorbed and are excreted intact in the faeces; in addition, microcrystalline cellulose, powdered and modified celluloses could be fermented by the intestinal flora in animals and humans. Specific toxicity data were not always available for all the celluloses evaluated in the present opinion and for all endpoints.
    [Show full text]
  • Type of the Paper (Article
    Supplementary Materials: In-Depth Study into Polymeric Materials in Low-Density Gastroretentive Formulations Nieves Iglesias, Elsa Galbis, Lucía Romero-Azogil, Elena Benito, Ricardo Lucas, M. Gracia García-Martín and M.-Violante de-Paz* 1. Tables with the chemical structure of the polymers most commonly used in FGRDDS Table S1. Semisynthetic cellulose derivatives. Chemical structures and tradenames. Swelling, gelling and matrix forming cellulose derivatives Substituents in glucopyranose units Acronym and common Molecular Material names /Tradename Weight (kDa) Hydroxypropylmethyl HPMC/MC R = -CH2CH(OH)CH3 or - cellulose/ Hypromellose/ CH3 or -H 30-1,200 Methyl cellulose Methocel®, Metolose® R = -CH3 or -H Hydroxypropyl HPC/ R = -CH2CH(OH)CH3 or - 40-1,150 cellulose Klucel ® HF H Hydroxyethyl cellulose HEC R = -CH2CH2OH or -H 90-1,300 Carboxymethyl cellulose CMC/NaCMC (and its sodium salts)(a) R = -CH2COONa 90-700 XrL-CMC/ or -CH2COOH or -H Sodium croscarmellose(b) Ac-Di-Sol® (a)CMC pKa = 4.0; (b)Cross-linked CMC; tradename: Ac-Di-Sol® Table S2. Other semisynthetic cellulose derivatives. Chemical structures and tradenames. Other cellulose derivatives Substituents in glucopyranose units Acronym and common Material names/ Tradename R = -COCH3 or -CO-C6H4-COOH Cellulose acetate phthalate CAP or -H Ethyl cellulose EC R = -CH2CH3 or -H R = -COCH3 or -COCH2CH2CH3 Cellulose acetate butyrate CAB or -H Microcrystalline cellulose MCC R = -H (mixtures of MCC and Avicel® NaCMC) 1 Table S3. Swelling, gelling and matrix forming materials used for floating GRDDS. Natural gums. Heteroglycans Material Chemical structure Guaran (From Guar Gum) Nonionic polysacch. Carrageenans: kappa: R = -H Iota: R = -SO3- Anionic polysacch. Gellan gum Anionic polysacch.
    [Show full text]
  • Food Additive Emulsifier E Number Lecithin E322 Sodium Phosphates
    Supplementary Table S1: Excluded food additives on the low emulsifier diet Food additive emulsifier E number Lecithin E322 Sodium phosphates E339i-iii Alginic acid E400 Sodium alginate E401 Potassium alginate E402 Ammonium alginate E403 Calcium alginate E404 Propylene glycol alginate E405 Agar E406 Carrageenan E407 Processed euchema seaweed E407a Carob bean gum E410 Guar gum E412 Tragacanth gum E413 Gum arabic E414 Xanthan gum E415 Karaya gum E416 Tara gum E417 Octenyl succinic acid modified gum arabic E423 Konjac flour E425 Soybean hemicellulose E426 Cassia gum E427 Polyoxyethylene (20) sorbitan monolaurate E432 (polysorbate 20) Polyoxyethylene (20) sorbitan monooleate E433 (polysorbate 80) Polyoxyethylene (20) sorbitan E434 monopalmitate (polysorbate 40) Polyoxyethylene (20) sorbitan E435 monostearate (polysorbate 60) Polyoxyethylene (20) sorbitan tristearate E436 (polysorbate 65) Pectins E440 Ammonium salts of phosphatidic acid E442 Glycerol esters of rosin E445 Food additive emulsifier E number Diphosphates E450(i-viii) Polyphosphates E452(i-vi) Celluloses E460(i-ii) Methyl cellulose E461 Ethyl cellulose E462 Hydroxypropyl cellulose E463 Hydroxypropyl methyl cellulose E464 Methyl ethyl cellulose E465 Sodium carboxymethyl cellulose E466 Ethyl hydroxyethyl cellulose E467 Cross-linked sodium E468 carboxymethylcellulose Sodium carboxymethyl cellulose E469 enzymatically hydrolysed Salts of fatty acids, with base of Ca, Mg, K, E470(i-iii) Na, Al, NH3 Mono- and di glycerides of fatty acids E471 Acetic and fatty acid esters of glycerol E472a
    [Show full text]
  • Formulation Considerations for the Management of Dry Eye Disease
    pharmaceutics Review Formulation Considerations for the Management of Dry Eye Disease Priyanka Agarwal 1, Jennifer P. Craig 2 and Ilva D. Rupenthal 1,* 1 Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland 1142, New Zealand; [email protected] 2 Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; [email protected] * Correspondence: [email protected]; Tel.: +64-9-923-6386 Abstract: Dry eye disease (DED) is one of the most common ocular surface disorders characterised by a deficiency in quality and/or quantity of the tear fluid. Due to its multifactorial nature involving several inter-related underlying pathologies, it can rapidly accelerate to become a chronic refractory condition. Therefore, several therapeutic interventions are often simultaneously recommended to manage DED efficiently. Typically, artificial tear supplements are the first line of treatment, followed by topical application of medicated eyedrops. However, the bioavailability of topical eyedrops is generally low as the well-developed protective mechanisms of the eye ensure their rapid clearance from the precorneal space, thus limiting ocular penetration of the incorporated drug. Moreover, excipients commonly used in eyedrops can potentially exhibit ocular toxicity and further exacerbate the signs and symptoms of DED. Therefore, formulation development of topical eyedrops is rather challenging. This review highlights the challenges typically faced in eyedrop development, in particular, those intended for the management of DED. Firstly, various artificial tear supplements currently on the market, their mechanisms of action, as well as their application, are discussed.
    [Show full text]
  • Methyl Cellulose
    METHYL CELLULOSE Dossier prepared with and submitted on behalf of: Dow Wolff Cellulosics for evaluation pursuant to Regulation (EC) 258/97 (as amended) on novel foods and novel food ingredients by the UK Competent Authority on Novel Foods (UK Food Standards Agency) November, 2011 Authors: Dow Wolff Cellulosics Regulatory Services, Leatherhead Food Research Contents 1 EXECUTIVE SUMMARY ..................................................................................... 4 2 ADMINISTRATIVE DETAILS .............................................................................. 6 2.1 Name and Contact Details for Correspondence ................................................ 6 3 INTRODUCTION ................................................................................................. 7 4 Specification of the Novel Food........................................................................ 9 4.1 General Description .......................................................................................... 9 4.2 Analytical Information ...................................................................................... 10 5 Effect of the Production Process Applied to the Novel Food ....................... 13 5.1 Raw Materials ................................................................................................. 15 5.2 Production Process ......................................................................................... 15 6 History of the Organism Used as the Source of the Novel Food .................. 17 7 Anticipated
    [Show full text]
  • Aggregation and Gelation in Hydroxypropylmethyl Cellulose Aqueous Solutions ∗ Sérgio M.C
    Journal of Colloid and Interface Science 327 (2008) 333–340 Contents lists available at ScienceDirect Journal of Colloid and Interface Science www.elsevier.com/locate/jcis Aggregation and gelation in hydroxypropylmethyl cellulose aqueous solutions ∗ Sérgio M.C. Silva a,b, Fátima V. Pinto a, Filipe E. Antunes c,MariaG.Miguela, João J.S. Sousa b, Alberto A.C.C. Pais a, a Chemistry Department, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal b Faculty of Pharmacy, University of Coimbra, Rua do Norte, 3000-295 Coimbra, Portugal c Chemical Engineering Department, University of Coimbra, Polo II - Pinhal de Marrocos, 3030-290 Coimbra, Portugal article info abstract Article history: In this work we present an analysis of the thermal behavior of hydroxypropylmethyl cellulose aqueous Received 17 July 2008 solutions, from room temperature to higher temperatures, above gelation. We focus on significant aspects, Accepted 28 August 2008 essentially overlooked in previous work, such as the correlation between polymer hydrophobicity and Available online 4 September 2008 rheological behavior, and the shear effect on thermal gelation. Micropolarity and aggregation of the polymer chains were monitored by both UV/vis and fluorescence spectroscopic techniques, along with Keywords: Hydroxypropylmethyl cellulose polarized light microscopy. Gel formation upon heating was investigated using rheological experiments, Gelation mechanism with both large strain (rotational) tests at different shear rates and small strain (oscillatory) tests. The Rheology present observations allow us to compose a picture of the evolution of the system upon heating: firstly, Micropolarity index polymer reptation increases due to thermal motion, which leads to a weaker network. Secondly, above ◦ 55 C, the polymer chains become more hydrophobic and polymer clusters start to form.
    [Show full text]
  • Basic Concepts of Cellulose Polymers - a Comprehensive Review
    Archives of Pharmacy Practice Review Article ISSN 2045-080X Vol 3 , Issue 3 , 2012 Basic Concepts Of Cellulose Polymers - A Comprehensive Review Harika K, Sunitha K, Pavan Kumar P, Maheshwar K and Madhusudan Rao Y* Department of Pharmaceutics, National facilities in Engineering and Technology with Industrial Collaboration (NAFETIC) centre, University College of Pharmaceutical Sciences, Kakatiya University, Warangal – 506 009, A.P. India. Citation: Harika K, Sunitha K, Pavan Kumar P, Maheshwar K and Madhusudan Rao Y. Basic Concepts Of Cellulose Polymers- A Comprehensive Review. Archives of Pharmacy Practice. 2012; 3(3)pp202-216. Abstract Man’s pursuance for new and improved materials has been should promote innovation. To assist the exploitation expanding with time and it can be said that it is unending. of novel drug delivery systems the need for polymers Though introduced very late in the chain of materials, continues to increase. polymers occupy a major place and pivotal position in our This review serves as a comprehensive source to improve materials map today. Unfolding of the science of polymers and understanding of cellulose derivative polymers and create polymer – based materials had evoked lot of interest and made new avenues in development of a delivery system. In them as a class of materials for their potential use in the field of addition, this review presents in-depth information on pharmaceuticals and industry based products. In recent years, various aspects of polymer chemistry, nomenclature, an awareness and understanding of these polymers has various polymer grades, physical characteristics of increased based upon the following factors. polymers, solubility, and the utility of polymers for As pharmaceutically active ingredients continue to become various drug delivery systems.
    [Show full text]
  • Evaluation of Cellulose Ethers for Conservation (1990)
    Research in Conservation 1990 3 R. L. Feller Evaluation M. Wilt of Cellulose Ethers for Conservation Evaluation of Cellulose Ethers for Conservation Research in Conservation 1990 3 R. L. Feller Evaluation M. Wilt of Cellulose Ethers for Conservation © 1990 by the J. Paul Getty Trust. All rights reserved Printed in the United States of America. Second printing, 1993 Library of Congress Cataloging-in-Publication Data Feller, Robert L. Evaluation of cellulose ethers for conservation / R.L. Feller, M. Wilt. p. cm. -- (Research in conservation : 3) Includes bibliographical references. ISBN 0-89236-099-2 : $16.00 1. Cellulose ethers. I. Wilt, M. (Myron) II. Title. III. Series. QD323.F45 1989 069' .53--dc20 89-16947 CIP The Getty Conservation Institute The Getty Conservation Institute (GCI), an operating program of the J. Paul Getty Trust, was created in 1982 to enhance the quality of conservation practice in the world today. Based on the belief that the best approach to conservation is interdisci- plinary, the Institute brings together the knowledge of conser- vators, scientists, and art historians. Through a combination of in-house activities and collaborative ventures with other orga- nizations, the Institute plays a catalytic role that contributes substantially to the conservation of our cultural heritage. The Institute aims to further scientific research, to increase conser- vation training opportunities, and to strengthen communica- tion among specialists. Research in Conservation This reference series is born from the concern and efforts of the Getty Conservation Institute to publish and make avail- able the findings of research conducted by the GCI and its individual and institutional research partners, as well as state- of-the-art reviews of conservation literature.
    [Show full text]
  • Liquid Crystalline Properties of Derivatives of Cellulose Isolated
    LIQUID CRYSTALLINE PROPERTIES OF HYDROXYPROPYL CELLULOSE PREPARED FROM DISSOLVED EGYPTIAN BAGASSE PULP RAGAB E. ABOU-ZEID,*,** NAHLA A. EL-WAKIL,* AHMED ELGENDY,* YEHIA FAHMY* and ALAIN DUFRESNE** *Cellulose and Paper Department, National Research Centre, 33 Bohouth Str., Dokki, Giza 12622, Egypt **Université Grenoble Alpes, CNRS, Grenoble INP, LGP2, F-38000 Grenoble, France ✉Corresponding author: Ahmed Elgendy, [email protected] Received June 26, 2020 Egyptian agricultural wastes were used for preparing advanced cellulosic derivatives possessing liquid crystalline properties. Cellulose was successfully isolated in pure form from Egyptian bagasse pulp. Hydroxypropylation was carried out on the obtained cellulose and the liquid crystalline properties were investigated. The prepared hydroxypropyl cellulose (HPC) was esterified with 4-alkyloxybenzoic acids, giving products with liquid crystalline properties. The molecular structure of HPC and a series of its esters – 4-alkoxybenzoloxypropyl cellulose (ABPC-m) – was confirmed by Fourier transform infrared (FT-IR) and 1H NMR spectroscopy. The liquid crystalline (LC) phases and transition behaviors were investigated using differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The lyotropic behavior in dimethyl acetamide (DMA) was investigated using an Abee refractometer, and the critical concentration was determined by measuring the refractive index of the solutions in DMA. Keywords: cellulose, bagasse pulp, 4-alkyloxybenzoic acids, liquid crystalline properties, phase transitions INTRODUCTION Cellulose, the most abundant natural polymer, could be a primary chemical resource in the future, as it is renewable, biodegradable, biocompatible, and derivatizable.1 However, cellulose has not yet reached its potential applications in many areas, because it is difficult to process in normal solutions or in the melting state on account of its strong intermolecular and intramolecular hydrogen bonding system.
    [Show full text]