1 Preservation of Quality Through Packaging
1.1 Quality and Shelf-Life
1.2 Physical and Chemical Interactions Between Plastics and Food or Pharmaceuticals
1.3 The Organization of this Book
Further Reading
2 Characteristics of Plastic Materials
2.1 Classification, Manufacture, and Processing Aids
2.1.1 Classification and Manufacture of Plastics
2.1.1.1 Raw Materials and Polymerization Processes
2.1.1.2 Addition Polymerization
1 Preservation of Quality Through Packaging
1.1 Quality and Shelf-Life
1.2 Physical and Chemical Interactions Between Plastics and Food or Pharmaceuticals
1.3 The Organization of this Book
Further Reading
2 Characteristics of Plastic Materials
2.1 Classification, Manufacture, and Processing Aids
2.1.1 Classification and Manufacture of Plastics
2.1.1.1 Raw Materials and Polymerization Processes
2.1.1.2 Addition Polymerization
2.1.1.3 Condensation Polymerization
2.1.1.4 Synthesis of Copolymers, Block, and Graft Copolymers
2.1.1.5 Polymer Reactions
2.1.1.6 Plastic Processing
2.1.2 Processing Aids
2.1.2.1 Initiators and Crosslinkers
2.1.2.2 Catalysts
2.2 Structure and States of Aggregation in Polymers
2.2.1 Structure
2.2.2 States of Aggregation
2.3 The Most Important Plastics
2.3.1 Thermoplastics
2.3.1.1 Polyethylene
2.3.1.2 Polypropylene
2.3.1.3 Polybutene-1
2.3.1.4 Polyisobutylene
2.3.1.5 Poly-4-methylpentene-1 (P4MP1)
2.3.1.6 Ionomers
2.3.1.7 Cyclic Olefin Copolymers (COC)
2.3.1.8 Polystyrene
2.3.1.9 Polyvinyl Chloride
2.3.1.10 Polyvinylidene Chloride
2.3.1.11 Thermoplastic Polyesters
2.3.1.12 Polycarbonate
2.3.1.13 Polyamide
2.3.1.14 polymethylmethacrylate
2.3.1.15 Polyoxymethylene or Acetal Resin
2.3.1.16 Polyphenylene Ether (PPE)
2.3.1.17 Polysulfone
2.3.1.18 Fluoride Containing Polymers
2.3.1.19 Polyvinylether
2.3.2 Thermosets
2.3.2.1 Amino Resins (UF, MF)
2.3.2.2 Unsaturated Polyester (UP)
2.3.3 Polyurethanes
2.3.4 Natural and Synthetic Rubber
2.3.5 Silicones
2.3.6 Plastics Based on Natural Polymers Regenerated Cellulose
2.3.6.1 Biodegradable Polymers
2.3.7 Coatings and Adhesives
2.3.7.1 Lacquers
2.3.7.2 Plastic Dispersions
2.3.7.3 Microcrystalline Waxes
2.3.7.4 Temperature-Resistant Coatings
2.3.7.5 Printing Inks and Varnishes
References
3 Polymer Additives
3.1 Introduction
3.2 Antifogging Agents
3.3 Antistatic Agents
3.4 Blowing Agents
3.5 Colorants
3.6 Fillers and Reinforcing Agents
3.7 Lubricants
3.8 Nucleating Agents
3.9 Optical Brighteners
3.10 Plasticizers
3.11 Stabilizers
3.11.1 Antiacids
3.11.2 Antimicrobials
3.11.3 Antioxidants
3.11.3.1 Chain-Breaking Antioxidants
3.11.3.2 Hydroperoxide Deactivating Antioxidants
3.11.4 Dehydrating Agent
3.11.5 Heat Stabilizers
3.11.6 Light Stabilizers
3.11.6.1 Light Screening Pigments and UV Absorbers
3.11.6.2 Photoantioxidants
3.12 Transformation Products of Plastic Stabilizers
3.12.1 Transformation Products from Phenolic Antioxidants and UV Absorbers
3.12.2 Transformation products from Hydroperoxide Deactivating Antioxidants
3.12.3 Transformation Products from Hindered Amine Stabilizers
3.12.4 Transformation products from Heat Stabilizers for PVC
3.13 Conclusions
References
4 Partition Coefficients
4.1 Experimental Determination of Polymer/Liquid Partition Coefficients
4.2 Thermodynamics of Partition Coefficients
4.2.1 Equilibrium Between Different Phases in Ideal Solutions
4.2.1.1 Partitioning in Ideal Solutions: Nernst's Law
4.2.2 Equilibrium Between Different Phases in Nonideal Solutions
4.2.2.1 Partition Coefficients for Nonideal Solutions
4.2.3 Partition Coefficients for Systems with Polymers
4.2.4 Relationship Between Partition Coefficients and Solubility Coefficients
4.3 Estimation of Partition Coefficients Between Polymers and Liquids
4.3.1 Additive Molecular Properties
4.3.2 Estimation of Partition Coefficients Using QSAR and QSPR
4.3.3 Group-Contribution Thermodynamic Polymer Partition Coefficient Estimation Methods
4.3.3.1 Estimation of Partition Coefficients Using RST
4.3.3.2 Estimation of Partition Coefficients Using UNIFAC
4.3.3.3 Estimation of Partition Coefficients Using Group-Contribution Flory Equation-of-State
4.3.3.4 Estimation of Partition Coefficients Using Elbro Free Volume Model
4.3.3.5 Comparison of Thermodynamic Group-Contribution Partition Coefficient Estimation Methods
4.3.4 Vapor Pressure Index Partition Coefficient Estimation Method
4.3.4.1 Examples of Vapor Pressure Index Values
References
5 Models for Diffusion in Polymers
5.1 Diffusion in Polymers - The Classical Approach
5.1.1 Diffusion in Rubbery Polymers
5.1.1.1 Molecular Models
5.1.1.2 The Molecular Model of Pace and Datyner
5.1.1.3 Free-Volume Models
5.1.1.4 The Free-Volume Model of Vrentas and Duda
5.1.2 Diffusion in Glassy Polymers
5.2 Diffusion in Polymers - The Computational Approach
5.2.1 Molecular Dynamics
5.2.2 The Transition-State Approach
5.3 Conclusions
References
6 A Uniform Model for Prediction of Diffusion Coefficients with Emphasis on Plastic Materials
6.1 Introduction
6.2 Interaction Model
6.2.1 Model Assumptions
6.3 Prerequisites for Diffusion Coefficients
6.3.1 Critical Temperatures of n-Alkanes
6.3.2 Melting Temperatures of n-Alkanes
6.3.3 Melting Temperatures of Atom Clusters
6.3.4 Critical Compression Factor
6.3.5 The Entropy of Evaporation
6.3.6 The Reference Temperature and the Reference Molar Volume
6.4 The Diffusion Coefficient
6.4.1 Diffusion in Gases
6.4.2 Diffusion in the Critical State
6.4.3 Diffusion in Solids
6.4.3.1 Self-diffusion Coefficients in Metals
6.4.3.2 Self-Diffusion Coefficients in Semiconductors and Salts
6.4.3.3 Self-Diffusion Coefficients in n-Alkanes
6.4.4 Diffusion in Liquids
6.4.4.1 Self-Diffusion Coefficients in Metals
6.4.4.2 Self-Diffusion Coefficients in n-Alkanes
6.4.5 Diffusion in Plastic Materials
6.4.5.1 Diffusion Coefficients of n-Alkanes in polyethylene
6.4.5.2 Diffusion Coefficients of Additives in Polymers
References
7 Transport Equations and Their Solutions
7.1 The Transport Equations
7.1.1 The Terminology of Flow
7.1.2 The DifferentiaI Equations of Diffusion
7.1.3 The General Transport Equations
7.2 Solutions of the Diffusion Equation
7.2.1 Steady State
7.2.2 Nonsteady State
7.2.3 Diffusion in a Single-Phase Homogeneous System
7.2.3.1 Dimensionless Parameters and the Proportionality of Mass Transfer to the Square Root of Time
7.2.3.2 Comparison of Different Solutions for the Same Special Cases
7.2.4 Diffusion in Multiphase Systems
7.2.4.1 Diffusion in Polymer/Liquid Systems
7.2.4.2 Influence of Diffusion in Food
7.2.5 Surface Evaporation
7.2.6 Permeation Through Homogeneous Materials
7.2.7 Permeation Through a Laminate
7.2.8 Concentration Dependence of the Diffusion Coefficient
7.2.9 Diffusion and Chemical Reaction
7.3 Numerical Solutions of the Diffusion Equation
7.3.1 Why Numerical Solutions?
7.3.2 Finite-Difference Solution by the Explicit Method
7.3.2.1 von Neumann Stability Analysis
7.3.2.2 The Crank-Nicholson Implicit Method
7.3.3 Spatially Variable Diffusion Coefficient
7.3.4 Boundary Conditions
7.3.5 One-Dimensional Diffusion in Cylindrical and Spherical Geometry
7.3.6 Multidimensional Diffusion
References
8 Solution of the Diffusion Equation for Multilayer Packaging
8.1 Introduction
8.2 Methods for Solving the Diffusion Problem in a Multilayer (ML) Packaging
8.3 Solving the Diffusion Equation for a Multilayer Packaging in Contact with a Foodstuff
8.4 Development of a User-Friendly Software for the Estimation of Migration from Multilayer Packaging
References
9 User-Friendly Software for Migration Estimations
9.1 Introduction
9.2 MIGRATEST@Lite - A User-Friendly Software for Migration Estimations
9.2.1 Basic Features of MIGRATEST@Lite and Input Data Menus
9.2.2 Estimation of Migration with MIGRATEST@Lite
9.2.3 Output Information Delivered by MIGRATEST@Lite
9.2.4 Case Examples Computed with MIGRATEST@Lite
9.2.5 Migration Estimations with the MIGRATEST@EXP Software
9.2.6 Case Examples Computed with MIGRATEST@EXP
References
10 Permeation of Cases and Condensable Substances Through Monolayer and Multilayer Structures
10.1 Introduction: Barrier Function of Polymer-Based Packaging
10.2 Permeation Through Polymeric Materials
10.2.1 Substance Transport Through Monolayer Polymer Films
10.2.2 Substance Transport Through Multilayer Polymer Films (Laminates)
10.2.3 Units for Different Parameters
10.3 Substance Transport Through Single and Multilayer Polymer Substrates Combined with One Inorganic Barrier Layer
10.3.1 Numerical Modeling
10.3.2 Simplification: Barrier Improvement Factor
10.3.3 Multilayer Polymer Substrates Combined with One Inorganic Layer
10.3.4 Polymer Substrates Combined with an Inorganic Barrier Layer and Other Polymer Layers on Top of the Inorganic Layer
10.3.5 Temperature Behavior of the Structures Shown Above
10.3.6 Substance Transport Through Thin Polymer Layers Having Inorganic Layers on Both Sides
10.5 Substance Transport Through Polymers Filled with Particles
10.6 Experimental Findings: Polymer Films and One Inorganic Barrier Layer
10.6.1 Structures and Defects in Inorganic Barrier Layers on Polymer Substrates
10.6.2 Comparison of Model Calculations and Experimental Results for Combinations of Polymer Films and One Inorganic Barrier Layer
10.6.3 Apparent Additional Transport Mechanisms for Water Vapor
10.6.4 Properties of Systems with at least One Inorganic Layer Embedded Between to Polymer Layers or Films
10.7 Experimental Findings: Combinations of Polymer Films and More Than One Inorganic Barrier Layer
10.8.8 Experimental Findings: Polymers Filled with Platelet-Shaped Particles
10.9 Experimental Findings: Permeation of Flavors Through Mono- and Multilayer Films and Combinations with Inorganic Barrier Layers
10.10 Conclusions
References
11 Migration of Plastic Constituents
11.1 Definitions and Theory
11.1.1 Migration, Extraction, and Adsorption
11.1.2 Functional Barrier
11.1.3 Legal Migration Limits and Exposure
11.1.4 Parameters Determining Migration
11.2 Indirect Migration Assessment
11.2.1 Worst-Case (Total Mass Transfer) Assumption
11.2.2 General Considerations: Taking Solubility and/or Low Diffusivity of Certain Plastics into Account
11.2.3 Migration Assessment of Mono- and Multilayers by Application of Complex Mathematical Models
11.2.4 Multilayers
11.3 Migration Experiment
11.3.1 Direct Migration Measurement in Conventional and Alternative Simulants
11.3.2 Accelerated Migration Tests: Alternative Migration Tests
11.3.3 Choice of Appropriate Test Conditions
11.3.3.1 Food Simulants
11.3.3.2 Time-Temperature Conditions
11.3.3.3 Surface-to-Volume Ratio
11.3.3.4 Migration Contact
11.4 Analysis of Migration Solutions
11.4.1 Overall Migration
11.4.1.1 Aqueous and Alternative Volatile Simulants
11.4.1.2 Olive Oil
11.4.1.3 Modified polyphenylene Oxide (Tenax@)
11.4.2 Specific Migration
11.4.2.1 Vinyl Chloride EU Directives
11.4.2.2 EN 13130 Series
11.4.2.3 Further Standard Methods
11.4.2.4 Methods of Analysis in Petitions to the European Commission
11.4.2.5 Methods in Foods (Foodmigrosure Project)
11.5 Development of Methods, Validation, and Verification
11.5.1 Establishing (Juristically) Valid Performance of Methods
11.5.2 A Practical Guide for Developing and Prevalidation of Analytical Methods
11.5.3 Validation Requirements for EU Food Contact Petitions and US FDA Food Contact Notifications
11.5.4 Determination of the Detection Limit
11.5.5 Analytical Uncertainty
11.5.6 Use of the Precision Data from Fully Validated Methods
11.6 Sources of Errors
11.6.1 Highly Volatile Migrants
11.6.2 Reaction with Food/Simulant Constituents
11.6.3 Migrants in Reactive Processes (e.g., Primary Aromatic Amines from Adhesives)
11.7 Migration into Food Simulants in Comparison to Foods
11.8 Consideration of Non Intentionally Added Substances (NIAS) and Other not Regulated Migrants
References
12 US FDA Food Contact Materials Regulations
12.1 Introduction
12.2 Regulatory Authority
12.2.1 Federal Food, Drug and Cosmetic Act (FFDCA)
12.2.2 National Environmental Policy Act (NEPA)
12.3 Premarket Safety Assessment
12.3.1 Introduction
12.3.2 Chemistry Information
12.3.2.1 Migrant Levels in Food
12.3.2.2 Packaging Information
12.3.3 Toxicology Information
12.3.3.1 Safety Assessment
12.3.3.2 General Considerations
12.3.4 Environmental Information
12.3.4.1 Claim of categorical exclusion
12.3.4.2 Environmental Assessment (EA)
12.3.4.3 Polymerie Food Packaging Materials
12.3.4.4 Inadequacies in EAs
12.4 Final Thoughts
12.5 Conclusions
References
13 Community Legislation on Materials and Articles Intended to Come into Contact with Foodstuffs
13.1 Introduction
13.2 Community Legislation
13.2.1Directives/Regulations Applicable to all Materials and Articles
13.2.1.1 Framework Directives/Regulation
13.2.1.2 Regulation on Good Manufacturing Practice
13.2.2 Directives Applicable to One Category of Materials and Articles
13.2.2.1 Directive on Regenerated Cellulose Film
13.2.2.2 Directive on Ceramics
13.2.2.3 Directive on plastics Materials
13.2.2.4 Field of Application
13.2.2.5 EU List of Authorized Substances
13.2.2.6 Restricted Use of Authorized Substances (OML, SML, QM, and QMA)
13.2.2.7 Authorization of New Substances
13.2.2.8 Directives on the System of Checking Migration
13.2.2.9 Functional Barrier
13.2.2.10 Fat (Consumption) Reduction Factors
13.2.2.11 Declaration of Compliance
13.2.2.12 Specific Rules for Infants and Young Children
13.2.2.13 Special Restrictions for Certain Phthalates now Authorized at EU Level
13.2.2.14 Simulant for Milk and Milk products
13.2.2.15 Other Complementary Community Initiatives
13.2.3 Directives Concerning Individual or Groups of Substances
13.2.3.1 Directives on Vinyl Chloride
13.2.3.2 Directive on MEG and DEG in Regenerated Cellulose Film
13.2.3.3 Directive on Nitrosamines in Rubber Teats and Soothers
13.2.3.4 Regulation on the Restriction of Use of Certain Epoxy Derivatives
13.2.3.5 Directive on the Suspension of the Use of Azodicarbonamide as Blowing Agent in plastics
13.2.3.6 Regulation on Some Plasticizers in Gaskets in Lids
13.3 National Law and European Mutual Recognition
13.3.1 Future Commission Plans
13.4 National Legislations and Council of Europe Resolutions
13.5 Conclusions
14 Packaging Related Qff-Flavors in Foods
14.1 Introduction
14.2 Sensory Evaluation
14.3 Identification of Off-Flavor Compounds
14.4 Physical Chemical Parameters Determining Off-Flavors
14.5 Derivation of Threshold Concentrations of Sensory-Active Compounds
References
15 Possibilities and Limitations of Migration Modeling
15.1 Correlation of Diffusion Coefficients with Plastic Properties
15.2 The Partition Coefficient
References
Appendices
Appendix I
References
Appendix Il
References
Appendix III
A Selection of Additives Used in Many Plastic Materials
Index
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