Plastic Packaging Edited by OttoG.PiringerandAlbertL.Baner Further Reading Elias, H.-G. Macromolecules Volume1:ChemicalStructuresandSyntheses 2005 ISBN:978-3-527-31172-9 Elias, H.-G. Macromolecules Volume2:IndustrialPolymersandSyntheses 2007 ISBN:978-3-527-31173-6 Elias, H.-G. Macromolecules Volume3:PhysicalStructuresandProperties 2008 ISBN:978-3-527-31174-3 Elias, H.-G. Macromolecules Volume4:ApplicationsofPolymers 2009 ISBN:978-3-527-31175-0 Brennan,J. G. Food Processing Handbook 2006 ISBN:978-3-527-30719-7 Plastic Packaging Interactions with Food and Pharmaceuticals Edited by Otto G. Piringer and Albert L. Baner Second, Completely Revised Edition TheEditors AllbookspublishedbyWiley-VCHarecarefully produced.Nevertheless,authors,editors,and Dr.OttoG.Piringer publisherdonotwarranttheinformationcontained inthesebooks,includingthisbook,tobefreeof FABESForschungsGmbH errors.Readersareadvisedtokeepinmindthat Schragenhofstr.35 statements,data,illustrations,proceduraldetailsor 80992München otheritemsmayinadvertentlybeinaccurate. Germany LibraryofCongressCardNo.:appliedfor Dr.AlbertL.Baner NestlePurinaPetcare BritishLibraryCataloguing-in-PublicationData CheckerboardSquare Acataloguerecordforthisbookisavailablefromthe St.Louis,MO63164 BritishLibrary. USA Bibliographicinformationpublishedby theDeutscheNationalbibliothek DieDeutscheNationalbibliothekliststhis publicationintheDeutscheNationalbibliografie; detailedbibliographicdataareavailableinthe Internetat<http://dnb.d-nb.de> #2008WILEY-VCHVerlagGmbH&Co.KGaA, Weinheim Allrightsreserved(includingthoseoftranslationinto otherlanguages).Nopartofthisbookmaybe reproducedinanyform–byphotoprinting, microfilm,oranyothermeans–nortransmittedor translatedintoamachinelanguagewithoutwritten permissionfromthepublishers.Registerednames, trademarks,etc.usedinthisbook,evenwhennot specificallymarkedassuch,arenottobeconsidered unprotectedbylaw. Typesetting ThomsonDigital,Noida,India Printing betz-druckGmbH,Darmstadt BookBinding Litges&DopfGmbH,Heppenheim CoverDesign AnneChristineKeßler,Karlsruhe PrintedintheFederalRepublicofGermany Printedonacid-freepaper ISBN:978-3-527-31455-3 V Contents Preface XV List of Contributors XVII 1 PreservationofQualityThroughPackaging 1 AlbertBanerandOttoPiringer 1.1 QualityandShelf-Life 1 1.2 PhysicalandChemicalInteractionsBetweenPlasticsandFood orPharmaceuticals 4 1.3 TheOrganizationofthisBook 5 FurtherReading 12 2 CharacteristicsofPlasticMaterials 15 JohannesBrandschandOttoPiringer 2.1 Classification,Manufacture,andProcessingAids 15 2.1.1 ClassificationandManufactureofPlastics 16 2.1.1.1 RawMaterialsandPolymerizationProcesses 17 2.1.1.2 AdditionPolymerization 18 2.1.1.3 CondensationPolymerization 19 2.1.1.4 SynthesisofCopolymers,Block,andGraftCopolymers 19 2.1.1.5 PolymerReactions 20 2.1.1.6 PlasticProcessing 22 2.1.2 ProcessingAids 23 2.1.2.1 InitiatorsandCrosslinkers 24 2.1.2.2 Catalysts 25 2.2 StructureandStatesofAggregationinPolymers 26 2.2.1 Structure 26 2.2.2 StatesofAggregation 29 2.3 TheMostImportantPlastics 32 2.3.1 Thermoplastics 32 2.3.1.1 Polyethylene 32 PlasticPackaging.SecondEdition.EditedbyO.G.PiringerandA.L.Baner Copyright(cid:1)2008WILEY-VCHVerlagGmbH&Co.KGaA,Weinheim ISBN:978-3-527-31455-3 VI Contents 2.3.1.2 Polypropylene 34 2.3.1.3 Polybutene-1 36 2.3.1.4 Polyisobutylene 36 2.3.1.5 Poly-4-methylpentene-1(P4MP1) 36 2.3.1.6 Ionomers 36 2.3.1.7 CyclicOlefinCopolymers(COC) 37 2.3.1.8 Polystyrene 38 2.3.1.9 PolyvinylChloride 39 2.3.1.10 PolyvinylideneChloride 41 2.3.1.11 ThermoplasticPolyesters 41 2.3.1.12 Polycarbonate 42 2.3.1.13 Polyamide 43 2.3.1.14 Polymethylmethacrylate 44 2.3.1.15 PolyoxymethyleneorAcetalResin 45 2.3.1.16 PolyphenyleneEther(PPE) 45 2.3.1.17 Polysulfone 45 2.3.1.18 FluorideContainingPolymers 46 2.3.1.19 Polyvinylether 46 2.3.2 Thermosets 46 2.3.2.1 AminoResins(UF,MF) 47 2.3.2.2 UnsaturatedPolyester(UP) 47 2.3.3 Polyurethanes 48 2.3.4 NaturalandSyntheticRubber 49 2.3.5 Silicones 51 2.3.6 PlasticsBasedonNaturalPolymersRegeneratedCellulose 54 2.3.6.1 BiodegradablePolymers 54 2.3.7 CoatingsandAdhesives 55 2.3.7.1 Lacquers 56 2.3.7.2 PlasticDispersions 57 2.3.7.3 MicrocrystallineWaxes 57 2.3.7.4 Temperature-ResistantCoatings 58 2.3.7.5 PrintingInksandVarnishes 59 References 60 3 PolymerAdditives 63 JanPospíšilandStanislavNešpu°rek 3.1 Introduction 63 3.2 AntifoggingAgents 64 3.3 AntistaticAgents 65 3.4 BlowingAgents 65 3.5 Colorants 66 3.6 FillersandReinforcingAgents 66 3.7 Lubricants 67 3.8 NucleatingAgents 67 3.9 OpticalBrighteners 68 Contents VII 3.10 Plasticizers 68 3.11 Stabilizers 70 3.11.1 Antiacids 71 3.11.2 Antimicrobials 72 3.11.3 Antioxidants 72 3.11.3.1 Chain-BreakingAntioxidants 73 3.11.3.2 HydroperoxideDeactivatingAntioxidants 74 3.11.4 DehydratingAgent 75 3.11.5 HeatStabilizers 75 3.11.6 LightStabilizers 76 3.11.6.1 LightScreeningPigmentsandUVAbsorbers 76 3.11.6.2 Photoantioxidants 77 3.12 TransformationProductsofPlasticStabilizers 78 3.12.1 TransformationProductsfromPhenolicAntioxidantsandUV Absorbers 79 3.12.2 TransformationProductsfromHydroperoxideDeactivating Antioxidants 83 3.12.3 TransformationProductsfromHinderedAmine Stabilizers 84 3.12.4 TransformationProductsfromHeatStabilizersforPVC 85 3.13 Conclusions 86 References 86 4 PartitionCoefficients 89 AlbertBanerandOttoPiringer 4.1 ExperimentalDeterminationofPolymer/LiquidPartition Coefficients 89 4.2 ThermodynamicsofPartitionCoefficients 90 4.2.1 EquilibriumBetweenDifferentPhasesinIdealSolutions 91 4.2.1.1 PartitioninginIdealSolutions:Nernst’sLaw 92 4.2.2 EquilibriumBetweenDifferentPhasesinNonidealSolutions 93 4.2.2.1 PartitionCoefficientsforNonidealSolutions 94 4.2.3 PartitionCoefficientsforSystemswithPolymers 96 4.2.4 RelationshipBetweenPartitionCoefficientsandSolubility Coefficients 98 4.3 EstimationofPartitionCoefficientsBetweenPolymersand Liquids 99 4.3.1 AdditiveMolecularProperties 99 4.3.2 EstimationofPartitionCoefficientsUsingQSARandQSPR 102 4.3.3 Group-ContributionThermodynamicPolymerPartitionCoefficient EstimationMethods 102 4.3.3.1 EstimationofPartitionCoefficientsUsingRST 104 4.3.3.2 EstimationofPartitionCoefficientsUsingUNIFAC 104 4.3.3.3 EstimationofPartitionCoefficientsUsingGroup-Contribution FloryEquation-of-State 108 VIII Contents 4.3.3.4 EstimationofPartitionCoefficientsUsingElbroFreeVolumeModel 108 4.3.3.5 ComparisonofThermodynamicGroup-ContributionPartition CoefficientEstimationMethods 108 4.3.4 VaporPressureIndexPartitionCoefficientEstimationMethod 109 4.3.4.1 ExamplesofVaporPressureIndexValues 112 References 118 5 ModelsforDiffusioninPolymers 123 PeterMercea 5.1 DiffusioninPolymers–TheClassicalApproach 125 5.1.1 DiffusioninRubberyPolymers 126 5.1.1.1 MolecularModels 126 5.1.1.2 TheMolecularModelofPaceandDatyner 129 5.1.1.3 Free-VolumeModels 131 5.1.1.4 TheFree-VolumeModelofVrentasandDuda 133 5.1.2 DiffusioninGlassyPolymers 135 5.2 DiffusioninPolymers–TheComputationalApproach 140 5.2.1 MolecularDynamics 142 5.2.2 TheTransition-StateApproach 150 5.3 Conclusions 154 References 158 6 AUniformModelforPredictionofDiffusionCoefficientswith EmphasisonPlasticMaterials 163 OttoPiringer 6.1 Introduction 163 6.2 InteractionModel 166 6.2.1 ModelAssumptions 166 6.3 PrerequisitesforDiffusionCoefficients 168 6.3.1 CriticalTemperaturesofn-Alkanes 168 6.3.2 MeltingTemperaturesofn-Alkanes 170 6.3.3 MeltingTemperaturesofAtomClusters 173 6.3.4 CriticalCompressionFactor 175 6.3.5 TheEntropyofEvaporation 175 6.3.6 TheReferenceTemperatureandtheReferenceMolarVolume 176 6.4 TheDiffusionCoefficient 178 6.4.1 DiffusioninGases 178 6.4.2 DiffusionintheCriticalState 181 6.4.3 DiffusioninSolids 181 6.4.3.1 Self-diffusionCoefficientsinMetals 181 6.4.3.2 Self-DiffusionCoefficientsinSemiconductorsandSalts 183 6.4.3.3 Self-DiffusionCoefficientsinn-Alkanes 184 6.4.4 DiffusioninLiquids 184 6.4.4.1 Self-DiffusionCoefficientsinMetals 184 6.4.4.2 Self-DiffusionCoefficientsinn-Alkanes 185 Contents IX 6.4.5 DiffusioninPlasticMaterials 188 6.4.5.1 DiffusionCoefficientsofn-AlkanesinPolyethylene 188 6.4.5.2 DiffusionCoefficientsofAdditivesinPolymers 191 References 193 7 TransportEquationsandTheirSolutions 195 OttoPiringerandTitusBeu 7.1 TheTransportEquations 195 7.1.1 TheTerminologyofFlow 196 7.1.2 TheDifferentialEquationsofDiffusion 197 7.1.3 TheGeneralTransportEquations 200 7.2 SolutionsoftheDiffusionEquation 201 7.2.1 SteadyState 202 7.2.2 NonsteadyState 202 7.2.3 DiffusioninaSingle-PhaseHomogeneousSystem 203 7.2.3.1 DimensionlessParametersandtheProportionalityofMassTransfer totheSquareRootofTime 209 7.2.3.2 ComparisonofDifferentSolutionsfortheSameSpecialCases 212 7.2.4 DiffusioninMultiphaseSystems 213 7.2.4.1 DiffusioninPolymer=LiquidSystems 213 7.2.4.2 InfluenceofDiffusioninFood 224 7.2.5 SurfaceEvaporation 225 7.2.6 PermeationThroughHomogeneousMaterials 227 7.2.7 PermeationThroughaLaminate 228 7.2.8 ConcentrationDependenceoftheDiffusionCoefficient 228 7.2.9 DiffusionandChemicalReaction 229 7.3 NumericalSolutionsoftheDiffusionEquation 230 7.3.1 WhyNumericalSolutions? 230 7.3.2 Finite-DifferenceSolutionbytheExplicitMethod 231 7.3.2.1 vonNeumannStabilityAnalysis 236 7.3.2.2 TheCrank–NicholsonImplicitMethod 237 7.3.3 SpatiallyVariableDiffusionCoefficient 240 7.3.4 BoundaryConditions 241 7.3.5 One-DimensionalDiffusioninCylindricalandSpherical Geometry 243 7.3.6 MultidimensionalDiffusion 245 References 246 8 SolutionoftheDiffusionEquationforMultilayerPackaging 247 ValerTosaandPeterMercea 8.1 Introduction 247 8.2 MethodsforSolvingtheDiffusionProbleminaMultilayer(ML) Packaging 248 8.3 SolvingtheDiffusionEquationforaMultilayerPackagingin ContactwithaFoodstuff 251 X Contents 8.4 DevelopmentofaUser-FriendlySoftwarefortheEstimationof MigrationfromMultilayerPackaging 256 References 261 9 User-FriendlySoftwareforMigrationEstimations 263 PeterMercea,LiviuPetrescu,OttoPiringerandValerTosa 9.1 Introduction 263 9.2 MIGRATEST#Lite–AUser-FriendlySoftwareforMigration Estimations 266 # 9.2.1 BasicFeaturesofMIGRATEST LiteandInputDataMenus 266 # 9.2.2 EstimationofMigrationwithMIGRATEST Lite 276 # 9.2.3 OutputInformationDeliveredbyMIGRATEST Lite 278 # 9.2.4 CaseExamplesComputedwithMIGRATEST Lite 278 # 9.2.5 MigrationEstimationswiththeMIGRATEST EXPSoftware 281 # 9.2.6 CaseExamplesComputedwithMIGRATEST EXP 287 References 296 10 PermeationofGasesandCondensableSubstancesThrough MonolayerandMultilayerStructures 297 Horst-ChristianLangowski 10.1 Introduction:BarrierFunctionofPolymer-Based Packaging 297 10.2 PermeationThroughPolymericMaterials 302 10.2.1 SubstanceTransportThroughMonolayerPolymerFilms 303 10.2.2 SubstanceTransportThroughMultilayerPolymerFilms (Laminates) 305 10.2.3 UnitsforDifferentParameters 307 10.3 SubstanceTransportThroughSingleandMultilayerPolymer SubstratesCombinedwithOneInorganicBarrierLayer 307 10.3.1 NumericalModeling 307 10.3.2 Simplification:BarrierImprovementFactor 311 10.3.3 MultilayerPolymerSubstratesCombinedwithOneInorganic Layer 313 10.3.4 PolymerSubstratesCombinedwithanInorganic BarrierLayerandOtherPolymerLayersonTopof theInorganicLayer 314 10.3.5 TemperatureBehavioroftheStructuresShownAbove 316 10.3.6 SubstanceTransportThroughThinPolymerLayersHaving InorganicLayersonBothSides 317 10.5 SubstanceTransportThroughPolymersFilledwith Particles 320 10.6 ExperimentalFindings:PolymerFilmsandOneInorganic BarrierLayer 321 10.6.1 StructuresandDefectsinInorganicBarrierLayersonPolymer Substrates 323