MOLECULAR CHARACTERIZATION OF POLYMERS A Fundamental Guide MOLECULAR CHARACTERIZATION OF POLYMERS A Fundamental Guide Edited by M I M UHAMMAD MRAN ALIK H.E.J.ResearchInstituteofChemistry, InternationalCenterforChemicalandBiologicalSciences(ICCBS), UniversityofKarachi,Karachi,Pakistan J M IMMY AYS DepartmentofChemistry,UniversityofTennessee, Knoxville,TN,UnitedStates M R S UHAMMAD AZA HAH H.E.J.ResearchInstituteofChemistry, InternationalCenterforChemicalandBiologicalSciences(ICCBS), UniversityofKarachi,Karachi,Pakistan Elsevier Radarweg29,POBox211,1000AEAmsterdam,Netherlands TheBoulevard,LangfordLane,Kidlington,OxfordOX51GB,UnitedKingdom 50HampshireStreet,5thFloor,Cambridge,MA02139,UnitedStates Copyright©2021ElsevierInc.Allrightsreserved. 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LibraryofCongressCataloging-in-PublicationData AcatalogrecordforthisbookisavailablefromtheLibraryofCongress BritishLibraryCataloguing-in-PublicationData AcataloguerecordforthisbookisavailablefromtheBritishLibrary ISBN:978-0-12-819768-4 ForinformationonallElsevierpublications visitourwebsiteathttps://www.elsevier.com/books-and-journals Publisher:MatthewDeans AcquisitionsEditor:EdwardPayne EditorialProjectManager:CharlotteRowley ProductionProjectManager:PremKumarKaliamoorthi CoverDesigner:GregHarris TypesetbySPiGlobal,India Contributors LucaBaiamonte DepartmentofChemistry, andBiologicalSciences(ICCBS),Universityof ColoradoSchoolofMines,Golden,CO,United Karachi,Karachi,Pakistan States S.KimRatanathanwongsWilliams Department JosefBrandt DepartmentAnaylsis,Leibniz- ofChemistry,ColoradoSchoolofMines, Institutfu€rPolymerforschungDresdene.V., Golden,CO,UnitedStates Dresden,Germany AlbenaLederer DepartmentAnaylsis,Leibniz- TaihyunChang DepartmentofChemistryand Institutfu€rPolymerforschungDresdene.V.; DivisionofAdvancedMaterialsScience, SchoolofScience,TechnischeUniversit€at PohangUniversityofScienceandTechnology, Dresden,Dresden,Germany;Departmentof Pohang,SouthKorea ChemistryandPolymerScience,Stellenbosch MarkD.Dadmun DepartmentofChemistry, University,Matieland,SouthAfrica UniversityofTennessee,Knoxville;Chemical WeiLu TosohBioscienceLLC,KingofPrussia, SciencesDivision,OakRidgeNational PA,UnitedStates Laboratory,OakRidge,TN,UnitedStates MuhammadImranMalik H.E.J.Research NadiaEdwin DepartmentofHealthand InstituteofChemistry,InternationalCenterfor BiomedicalSciences,AdventHealthUniversity, ChemicalandBiologicalSciences(ICCBS), Orlando,FL,UnitedStates UniversityofKarachi,Karachi,Pakistan AnthonyP.Gies TheDowChemicalCompany, JimmyMays DepartmentofChemistry, LakeJackson,TX,UnitedStates UniversityofTennessee,Knoxville,TN,United DavidGillespie TosohBioscienceLLC,Kingof States Prussia,PA,UnitedStates ToshikazuMiyoshi DepartmentofPolymer AndrewGorman SchoolofMaterialsScience& Science,TheUniversityofAkron,Akron,OH, UnitedStates Engineering,GeorgiaInstituteofTechnology, Atlanta,GA,UnitedStates HaraldPasch DepartmentofChemistryand AlexanderS.Gubarev Departmentof PolymerScience,UniversityofStellenbosch, Stellenbosch,SouthAfrica MolecularBiophysicsandPhysicsofPolymers, Saint-PetersburgStateUniversity,Saint- JigneshkumarPatel IntelCorporation Petersburg,Russia (Chandler),Chandler,AZ,UnitedStates ShawLingHsu PolymerScienceand GeorgesM.Pavlov InstituteofMacromolecular EngineeringDepartment,Universityof Compounds,RussianAcademyofSciences, Massachusetts(Amherst),Amherst,MA, Saint-Petersburg,Russia UnitedStates IgorPerevyazko DepartmentofMolecular WayneHuberty AdvancedComposites BiophysicsandPhysicsofPolymers,Saint- Institute,MississippiStateUniversity, PetersburgStateUniversity,Saint-Petersburg, Starkville,MS,UnitedStates Russia MuhammadImran H.E.J.ResearchInstituteof JawadurRehman H.E.J.ResearchInstituteof Chemistry,InternationalCenterforChemical Chemistry,InternationalCenterforChemical ix x Contributors andBiologicalSciences(ICCBS),Universityof WilliamC.Smith DepartmentofChemistry, Karachi,Karachi,Pakistan ColoradoSchoolofMines,Golden,CO,United SebastienRouzeau TosohBioscienceLLC,King States ofPrussia,PA,UnitedStates AliSoleymannezhad TosohBioscienceLLC, PaulS.Russo SchoolofMaterialsScience& KingofPrussia,PA,UnitedStates Engineering;SchoolofChemistry& KirilA.Streletzky DepartmentofPhysics, Biochemistry,GeorgiaInstituteofTechnology, ClevelandStateUniversity,Cleveland,OH, Atlanta,GA,UnitedStates UnitedStates SalimSaifullah H.E.J.ResearchInstituteof MichaelToney DepartmentofChemistry, Chemistry,InternationalCenterforChemical ColoradoSchoolofMines,Golden,CO,United andBiologicalSciences(ICCBS),Universityof States Karachi,Karachi,Pakistan XujunZhang WyattTechnologyCorporation, MuhammadRazaShah H.E.J.Research SantaBarbara,CA,UnitedStates InstituteofChemistry,InternationalCenterfor WeiweiZhao NingboMaterialsInstitute, ChemicalandBiologicalSciences(ICCBS), Ningbo,China UniversityofKarachi,Karachi,Pakistan Foreword As we contemplate the centennial of macromolecular chemistry, we may be reasonably certain that Hermann Staudinger never said “Polymer scientia est omnis divisa in partes tres,” but if he had, he would have been right! The first part of polymer chemistry is synthesis: whatmolecularstructurescanwemake,howeasily,andhowreproducibly?Thethirdpart comprisesmaterialproperties:whatisthispolymergoodfor,howcanwemakeitbetter,and howcanwecombinemultipledesirablepropertiesinonematerial?Theintermediatedomain, and the essential component in order to close the structure-property loop, is polymer characterization: what did we make, exactly? Thereisnodoubtthatpolymercharacterizationis,ingeneral,aformidableexperimental challenge.Attherootoftheproblemistheunavoidablefactthatallsyntheticpolymersarehet- erogeneousintheirmolecularstructure.Asimplecalculationrevealsthatevenatankcarfullof homopolymerwillnotcontaintwomoleculesthatarepreciselyidentical.Notonlyistherea distribution of molar mass, but there is also heterogeneity in multiple variables, including, forexample,regioisomerism,stereochemistry,long-andshort-chainbranching,andcopoly- mersequenceandcomposition.Ideally,wewouldliketocharacterizeallofthesedistributions, atleasttothelevelofameanvalueandavariance.Thisgoaliscurrentlybeyondthecapabilities ofmostlaboratories,althoughexperimentalsciencecontinuestoadvancesignificantly. Itisnosurprisethatfullmolecularcharacterizationdemandsasuiteofexperimentaltools. Eachtechniquewillprovidevaluableinformation,butnonecanbesensitivetoallofthevari- ablesofinterest.Thiscreatesafurtherchallengeforthepolymerscientist:howtodecidewhich techniquestouse,andhowtousethemeffectively?Itistemptingtovieweachinstrumentasa blackbox:insertsomesamplematerial,andoutpopsananswer(typicallywitharidiculous numberofsignificantfigures).Asexperimentalscientists,weknowthisisdangerous;every techniquereliesonasetofassumptions,whichmayormaynotapplyforthesamplewecare about.Wecanconsultatextbook,or,morelikely,Wikipedia,andfindabriefdiscussionofthe technique, and a statement of the working equations. While helpful, this is not sufficient. A good practitioner needs to understand the assumptions, and also to be conversant with thestrengthsandweaknesses,theopportunitiesandblindspots,ofeachcharacterizationtool. ThisisthevoidthatMolecularCharacterizationofPolymers:AFundamentalGuideaimstofill. Theauthorsadoptatutorialstyle,sothatspecificpriorknowledgeisnotrequired.And,by taking this approach, the reader is empowered to acquire a deeper understanding of the theory underlying each approach. As noted before, there have been substantial recent ad- vancesininstrumentaltechniques,andthusthisup-to-datetreatmentwillbeveryvaluable for experienced practitioners as well. Timothy P. Lodge University of Minnesota, Minneapolis, MN, United States xi Preface It is very appropriate as we celebrate in tacticity, mode of monomer insertion (e.g., 2020the100-yearanniversaryofNobelLau- head-to-tail or head-to-head), chain con- reate Hermann Staudinger’s “discovery” of formation (flexibility), end groups, and polymers, that we assemble this new book branching (long chain and/or short chain). on Molecular Characterization of Polymers: A Copolymers are further complicated by Fundamental Guide. This is because Stau- monomer sequence distributions and varia- dinger,beginningin1920until1930,utilized tions in comonomer content across the aseriesofingeniousmolecularcharacterization MWD. All of these factors affect polymer studiestoprovethelongchainnatureofpoly- processing and the properties of the poly- mers,theirhighmolecularweights,andtheir mericmaterial,butpolymercharacterization distribution of chain lengths (molecular methods only yield average values and dis- weightdistribution,MWD)[1–3].Thiswork tributionsofkeymolecularparameters.Even earnedStaudingertheNobelPrizeinChem- today,nearlyahalfcenturysinceBillmeyer’s istry in 1953. statements,despitealltheadvancesinchar- In the decades after Staudinger’s discov- acterizationtechniquesandcomputation,the ery of polymers, the synthesis of polymers thoroughandaccuratemolecularcharacteri- of ever-increasing complexity led to the zationofpolymericmaterialsremainshighly “polymerage”ofmaterialswhichcontinues challenging. to this day, and new methods have been Anotherfactorcomplicatingthethorough continually developed in order to better characterization of polymers is the need to characterize polymers. However, even in employacombinationofdifferentcharacter- 1975, the eminent polymer scientist Fred ization techniques, as well as some knowl- Billmeyerstated“…characterizationofpoly- edge on how the polymer was synthesized, mersisinherentlymoredifficultthanthatof in order to rigorously characterize even the othermaterials.Polymersareroughlyequiv- simplest of polymers. Unfortunately, scien- alent in complexity to, if not more complex tistsactivelyinvolvedincharacterizingpoly- than,othermaterials,ateveryphysicallevel mers, either in industry or in academia, are of organization from microscopic to macro- usually specialists in one or two analytical scopic…” and “We would wish, ideally, to techniques and lack detailed knowledge in characterizeallaspectsofpolymerstructure a wide range of complementary polymer in enough detail to predict its performance characterizationtechniques,aswellaspoly- from first principles. I seriously doubt that mer synthesis methods and their impact on this will ever be possible…” [4]. polymer structure, that must be employed Billmeyer’s remarks stem from the fact inordertounderstandthepolymer’smolec- that synthetic polymers always exhibit a ular structure in detail. As examples, in distribution of chain lengths or MWD. industry analytical chemists are often Homopolymers are further complicated by confronted for the first time with xiii xiv Preface characterizing polymers and theymay have Chapter4describesbasicprinciplesandap- littleornoexperienceincharacterizingsuch plicationsoffieldflowfractionation(FFF)to complexmixtures.Also,fewpolymerscien- polymers.Chapter5focusesontheindustri- tistsarerigorouslytrainedinawiderangeof ally important area of characterization of polymercharacterization techniques. polyolefins, which constitute half of the an- Thus the primary purpose of this book is nual polymer production worldwide. Be- toserveasatextbookforacourse(academic cause of their limited solubility, polyolefins course or short course) on polymer charac- presentspecialchallengesintheircharacter- terization in order to better train the next ization. Multidetector SEC of polyolefins is generation of polymer characterization discussed, along with crystallinity-based experts.Thisbookisthuswritteninatutorial techniques such as temperature rising elu- style to serve as an introduction to the vari- tionfractionationandcrystallizationanalysis ous polymer characterization techniques. fractionation. We anticipate that this book, written in this Chapter 6 describes the use of combina- style,willalsobeusefultoscientistsinindus- tions of fundamental hydrodynamic ap- trial polymer analysis laboratories who proaches (analytical ultracentrifugation, are applying a characterization technique intrinsic viscosity, translational diffusion, to polymers for the first time. In addition to andSEC)tocharacterizemolecularweights, fundamentals,wehavealsoincludedineach dimensions, and conformation. These com- chapter recent advances in the technique, bined techniques are especially useful with information on instrumentation, and recent complex polymers such as polyelectrolytes. applications tomakethisbookusefultosci- Chapter 7 describes the use of viscometry entists with experience in a technique but to measure polymer size, molecular weight, looking for updates on recent advances and aswellasgatherinsightintoconformational applications. characteristics and branching. Methods for Thisbookbeginswithseveralchapterson detecting and quantifying long chain chromatography of polymers. Chapter 1 in- branching, including viscometry, light scat- troducesbasicprinciplesofchromatography tering, and multidetector SEC are described ofpolymer,includingsizeexclusionchroma- in Chapter 8. tography (SEC), high performance liquid Chapter9isfocusedonrecentadvancesin chromatography (HPLC), and liquid chro- massspectrometryofpolymers,focusingon matography at the critical condition. Data MALDI-TOF-MS and MS/MS. Chapters 10 reductionmethodsandcolumntechnologies and 11 describe the use of vibrational spec- are discussed. Chapter 2 discusses troscopyandNMRforstructuralcharacteri- multidetectorSECofpolymers,usingdetec- zation of polymers, including end groups, torssuchaslightscatteringandviscosityde- composition, tacticity, etc. Chapters 12 and tectors, for characterizing simple and 13 describe the use of static and dynamic complex (copolymer, branched) polymers. light scattering to characterize polymer mo- SEC remains the workhorse for characteriz- lecularweights,sizes,thermodynamicinter- ingpolymermolecularweightdistributions. actions and conformations. Chapter 14 Chapter 3 discusses the use of temperature introduces LenS3, a new light scattering de- gradient interaction chromatography for tector that measures polymer molecular characterization of branched polymers weights and allows for radius of gyration and copolymers, end functionalized poly- measurements in the sub-10-nm range. The mers, and isotopically labeled polymers. use of X-rays and neutrons for probing xv Preface References polymerstructureandconformation,inbulk, thin film, and in solution, is described in € [1] H. Staudinger, Uber polymerisation, Ber. Deut. Chapter15alongwithselectedapplications. Chem.Ges.53(1920)1073–1085. Chapter 16 covers microscopy of polymers, [2] H. Staudinger, U€ber die Konstitution der withabasicintroductiontoSEM,TEM,and Hochpolymeren, Ber. Deut. Chem. Ges. 61 (1928) AFMandrecentapplicationstopolymers. 2427–2431. € [3] H. Staudinger, W. Heuer, Uber hochpolymere We are grateful to all the authors who Verbindungen, 33. Mitteilung: Beziehungen madethetimelyassemblyofthisbookpossi- zwischen Viscosit€at und Molekulargewicht bei ble even under the challenges imposed by Poly-styrolen,Ber.Deut.Chem.Ges.63(1930)222– the Covid-19 pandemic. 234. [4] F.W.Billmeyer,Trendsinpolymercharacterization, Muhammad Imran Malika, Jimmy Maysb, and J.Polym.Sci.Symp.55(1975)1–10. Muhammad Raza Shaha aUniversity of Karachi,Karachi, Pakistan bUniversity of Tennessee,Knoxville, TN, United States