Innovative Biopolymer Nanocomposites Thin Films For Food Packagings / Marwa Mohamed Faisal

Supervisor:

Thesis (M.A.)—Nile University, Egypt, 2018 .

"Includes bibliographical references"

Contents:
DEDICATION................................................................................................................... 2
Nomenclature .................................................................................................................... 3
Table of Contents .............................................................................................................. 4
LIST OF TABLES ............................................................................................................ 8
LIST OF FIGURES .......................................................................................................... 9
ABSTRACT ..................................................................................................................... 11
Chapter 1 ......................................................................................................................... 13
1. Introduction .......................................................................................................... 14
1.1. Background .................................................................................................. 14
1.2. Active package ............................................................................................. 15
1.3. Bio-based polymers ...................................................................................... 18
1.4. Fillers ............................................................................................................ 20
1.4.1. Cotton fibers (COT) .............................................................................. 20
1.4.2. Nano Cotton cellulose ........................................................................... 22
1.4.3. Egg Shells powder (ES) ........................................................................ 22
1.4.4. Aloe Vera (AV)..................................................................................... 23
1.4.5. Glycerol (G) .......................................................................................... 24
1.5. Thesis Scope and Objective ......................................................................... 25
Chapter 2 ......................................................................................................................... 26
2. Literature Review ................................................................................................ 27
2.1. Preface .......................................................................................................... 27
2.2. Polymer Matrix ............................................................................................ 28
2.2.1. Feasibility study .................................................................................... 28
2.2.2. Chitin and Chitosan............................................................................... 29
2.2.3. Chitosan Nanoparticles (NCS) .............................................................. 31
2.2.4. Chitosan used in active package systems .............................................. 32
2.3. Characterization of active packages ............................................................. 33
2.3.1. Bio Impedance ...................................................................................... 34
2.3.2. Investigation of Tomato ripening stages ............................................... 36
2.4. Statistical Analysis ....................................................................................... 37
2.4.1. Design Expert........................................................................................ 37
Chapter 3 ......................................................................................................................... 39
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3. Materials and Methods ........................................................................................ 40
3.1. Materials ....................................................................................................... 40
3.2. Methods of Characterization ........................................................................ 42
3.2.1. Sample preparation ............................................................................... 44
3.2.2. Extraction of chitosan chemically from shrimp exoskeleton grounded and non-grounded shells ................................................................................... 44
3.2.3. Extraction of chitosan (CS) from shrimp shells waste with different degrees of deacetylation ...................................................................................... 47
3.2.4. Synthesis and optimization of chitosan nano particles (NCS) ........ 48
3.3. Preparation of fillers ..................................................................................... 49
3.3.1. Preparation of cotton fibers ................................................................... 49
3.3.2. Preparation of Nano cotton fibers ......................................................... 50
3.3.3. Preparation of egg shells powder .......................................................... 50
3.3.4. Extraction of Aloe Vera gel .................................................................. 50
3.4. Preparation of CS and NCS composite films ............................................... 51
3.4.1. Preparation of CS films from grounded CS and non-grounded CS powders 51
3.4.2. Preparation of chitosan composite films by solvent casting process .... 52
3.4.3. Preparation of Nano chitosan composite films by solvent casting process 53
3.5. Methods of Characterization ........................................................................ 54
3.5.1. Hydrogen nuclear magnetic resonance NMR (1HNMR) ...................... 54
3.5.1. X-Ray Diffraction (XRD) ......................................................................... 55
3.5.2. Fourier transformation Infrared (FTIR) Spectrum ................................ 55
3.5.3. Water vapor permeability (WVP) ......................................................... 55
3.5.4. The particle size analysis of powders ................................................... 56
3.5.5. Apparent porosity.................................................................................. 56
3.5.6. Swelling degree and Solubility degree ................................................. 56
3.5.7. Electron Impedance spectroscopy (EIS) and weight loss % ................. 57
3.5.8. Soil Degradation Test ........................................................................... 59
3.5.9. Thermal gravimetric Analysis (TGA) of chitosan and nano chitosan composite films ................................................................................................... 60
3.5.10. Mechanical Measurement of composite films .................................. 60
3.5.11. Scanning electron Microscope (SEM) of composite films ............... 62
3.5.12. Statistical analysis: Design Expert of composite films ..................... 63
Chapter 4 ......................................................................................................................... 65
4. Results and Discussion ......................................................................................... 66
4.1. First evaluation ............................................................................................. 66
4.1.1. Proton nuclear magnetic resonance 1HNMR of grounded and non –grounded CS powders ......................................................................................... 66
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4.1.1.1. 1HNMR of extracted non- grounded chitosan with different DDA hours 68
4.1.2. X-Ray diffraction of grounded and non –grounded CS powders ......... 70
4.1.3. Fourier transformation Infrared (FT-IR) Spectra of grounded and non –grounded CS powders ......................................................................................... 71
4.1.4. Water Vapor permeability (WVP) on grounded and non –grounded chitosan films ...................................................................................................... 73
4.2. Evaluation of Nano particles ........................................................................ 74
Evaluation of the nanoparticles sizes prepared from chitosan powder and the cellulose powders that were extracted from cotton waste was performed as a second evaluation procedure. .................................................................................. 74
4.2.1. Particle size analyzer............................................................................. 74
4.3. Evaluation of CS and NCS composite films ................................................ 75
4.3.1. X-ray Diffraction (XRD) of composite films ....................................... 75
4.3.2. Fourier transformation Infrared (FTIR) Spectrum ................................ 80
4.4. Evaluation of best wt. % filler ratio ............................................................. 91
4.4.1. Determination of WVP ......................................................................... 91
4.5. Evaluation of physiochemical properties of CS and NCS composite films . 92
4.5.1. Apparent Porosity degree of CS and NCS ccomposite films ............... 93
4.5.2. Swelling degree of CS and NCS 25wt.% composite films ................... 94
4.5.3. Solubility degree of CS and NCS composite films ............................... 96
4.5.4. Impedance Spectroscopy and weight loss measurement ...................... 98
4.5.5. Rate of Degradation Test of CS, NCS composite films ...................... 104
4.5.6. Thermo gravimetric analysis (TGA) of CS, NCS composite films .... 106
4.5.7. The mechanical properties of Chitosan matrix ................................... 108
4.6. SEM analysis .............................................................................................. 112
4.6.1. SEM for Chitosan composite films with fillers 25 wt .% ................... 112
4.6.2. SEM for NCS composite films ........................................................... 114
4.7. Statistical analysis ...................................................................................... 116
Chapter 5 ....................................................................................................................... 122
5. Summary and Conclusion ................................................................................. 123
5.1. Summary .................................................................................................... 123
5.2. Conclusion .................................................................................................. 124
5.3. Future Perspectives .................................................................................. 126
References ...................................................................................................................... 128

Abstract:
The present study aims at developing novel polymer nano composites films for active packaging applications, by investigating different factors such as type of polymer, type of filler and wt. % of fillers. The synthesized Polymer Nano/composites films undergo several characterization techniques such as physical, mechanical and thermal characterization. The main goal is enhancing permeability, tensile strength and thermal properties of the produced films to act as potential candidates for possible industrial application such as wrapping films and packaging materials. A bio polymer was used in this study: chitosan (CS) which is a natural polymer that is extracted from shrimp wastes. In the current research, emphasis was made on the natural polymer due to its biodegradable nature and for proving better performance in concerning its permeability as membrane matrices. The polymer Nano/composites were prepared by mixing each polymer with natural fillers (cotton fibers, Nano cotton cellulose, aloe Vera, glycerol, egg shells powder) with different concentration (5%, 15%,25%,35%) and studying their influence on the prepared films properties.
CS composites and nano composite membranes were fabricated by mixing the polymer with cotton fibers (COT), nano cotton (NCOT), aloe Vera (AV), glycerol (G), and Egg shells powder (ES). Physical cross-linking of CS by sodium tripoly phosphate (TPP) was carried out in order to enhance the binding between the internal CS chains and form Chitosan Nano particles (NCS). Natural fillers with different ratios (5wt. %, 15wt. %, 25wt.%, 35wt.%) were added on physically on NCS and CS by solvent casting technique.
In the current research, analysis was classified into three steps. First, extraction of chitosan chemically from shrimp shells by two different forms and decide which one will be used in our work. Secondly, selection the best ratios by analyzing the intermolecular chemical bond between CS, NCS matrix with fillers using Fourier transformation infrared Spectrum (FTIR) and examine the phase transitions using X-ray Diffraction (XRD). Third, by selecting the suitable filler and this was determined
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through exploring water vapor permeability, impedance, physical properties, thermal stability, mechanical properties and SEM. The last step was investigating the suitable filler ratio using statistical analysis carried out by Design Expert software (DE) to find the filler and filler percentage required for the films.
The results revealed that polymer type, filler type and filler% play an essential role in controlling the thermal stability and accordingly the rest of the physicochemical and mechanical properties of all fabricated CS,NCS nano composite films. Adding fillers to CS matrix showed chemical combination which was confirmed by FTIR and XRD .CS/NCS composite films enhanced the thermal stability although there is a little increment in the onset temperature according to filler ratios, however in NCS nano composite membranes fillers decreases the thermal stability except egg shells . Moreover, the addition of fillers enhances the mechanical properties of CS films specially egg shells with ratios 15%, 25%. Experimental validation of these films were investigated using Electrochemical impedance spectroscopy (EIS) to show that ES films were the best in delaying the ripening of tomato fruit followed by Nano cotton cellulose. Impedance measurement and Mechanical properties weren’t performed on NCS composite films as films were too brittle owing to their thinner structures. The statistical analysis was in agreement with the experimental results, whereby CS matrix, type of filler and wt. % of filler were significant factors. The factors had a direct influence on, thermal stability, apparent porosity, permeability, swelling and solubility degree.
The current research showed that fabricated CS composite films can be effective candidates in active packaging systems as they enhance thermal, barrier and mechanical properties.

Text in English, abstracts in English.