Fractionated crystallization in semicrystalline polymers. (April 2021)

• Record Type: Journal Article
• Authors: Sangroniz, Leire; Wang, Bao; Su, Yunlan; Liu, Guoming; Cavallo, Dario; Wang, Dujin; Müller, Alejandro J.
• Is Part Of: Progress in polymer science. Volume 115(2021)
• Publication Date: 2021-04
• Subjects: Fractionated crystallization -- Heterogeneous nucleation -- Surface nucleation -- Homogeneous nucleation -- Self-nucleation -- Crystallization kinetics; 2-D two dimensional -- 3-D three dimensional -- A droplet surface area -- AAO Anodic Aluminum Oxide Templates -- aPP atactic poly(propylene) -- CNT Carbon nanotube -- DI Domain I or isotropic melt Domain -- DII Domain II or self-nucleation Domain -- DIII Domain III or self-nucleation and annealing Domain -- DIIIA Domain IIIA or Domain in which annealing is observed without self-nucleation -- DIIISA Domain IIISA or self-nucleation and annealing Domain, equivalent to Domain III -- DMBS 1, 3:2, 4-bis(3, 4-dimethyl-benzylidene sorbitol) -- DSC differential scanning calorimetry -- E-b-MB ethylene-b-(3-methyl-1-butene) -- E-b-VCH polyethylene-b-poly(vinylcyclohexane) -- E-b-SEB polyethylene-b-poly(styrene-r-ethylene-r-butene) -- E-GMA copolymer of ethylene and glycidyl methacrylate -- EPDM ethylene propylene diene methylene -- EPDM-g-MA ethylene propylene diene methylene grafted maleic anhydride -- f temperature correction term -- fZA fraction of droplets with exactly z impurities;G, growth rate -- HDPE high density poly(ethylene) -- hPN hydrogenated polynorbornene -- IV volume dependent nucleation rate -- IA area dependent nucleation rate -- iPP isotactic poly(propylene) -- k the overall crystallization rate constant -- Kgτ the energy barrier associated with the overall crystallization -- LDPE low density poly(ethylene) -- LLDPE linear low density poly(ethylene) -- LPE linear poly(ethylene) -- MA concentration of heterogeneities of type A in the bulk polymer -- MAVD average number of type A seeds per droplet with volume VD -- MA Maleated PP -- MA Blend 30 cPA6 (NH2 terminated PA)/70 PE-1 MAH(maleic anhydride):NH2 ratio 4:1 -- MC Blend 20 PA6/80 PE-3 MAH:NH2 ratio 3:1 -- MDs microdomains -- Mn number average molecular weight -- n Avrami index -- ngd Avrami term related to growth dimensionality -- nn Avrami term associated to nucleation -- N polymerization degree -- N/N0 is the fraction of droplets not yet crystallized at time t -- N0 is the total number of droplets that undergo nucleation -- Na+-MMT layered sodium montmorillonite -- NAs nucleating agents -- NA11 (4, 6-di-tert-butylphenyl)phosphate -- nm nanometer -- NMR nuclear magnetic resonance -- OBC olefin block copolymer -- P2VP poly(2-vinylpyridine) -- P3HT poly(3-hexylthiophene) -- P4tBS poly(4-tert-butyl styrene) -- PA6 poly(amide 6) -- PB poly(butadiene) -- PBA poly(butylene adipate) -- PBS poly(butylene succinate) -- PC poly(carbonate) -- PCL poly(caprolactone) -- PDI polydispersity index -- PE poly(ethylene) -- PEG poly(ethylene glycol) -- PEO poly(ethylene oxide) -- PEP poly(ethylene-alt-propylene) -- PES poly(ethylene suberate) -- PET poly(ethylene terephthalate) -- PHB poly(3-hydroxybutyrate) -- PI poly(isoprene) -- PLLA poly(L-lactide) -- PLOM Polarized Light Optical Microscopy -- PMMA poly(methyl methacrylate) -- POB poly(oxybutylene) -- POE poly(oxyethylene) -- POM poly(oxymethylene) -- PPDX poly(dioxanone) -- PPE poly(phenylene-ether) -- PPP poly(2, 5-dihexyloxy-p-phenylene) -- PNCs polymer nanocomposites -- aPS atactic poly(styrene) -- PS poly(styrene) -- P(S-ODMA) poly(styrene-block-octadecylmethacrylate) -- PVDF poly(vinylidene fluoride) -- P(VDF70-TrFE30) poly(vinylidene fluoride70-trifluorethyline30) -- PVSt poly(4-(vinylpheneyl)-1-butene)) -- QQ quinacridone quinone -- R gas constant -- RT room temperature -- SAXS small angle X-ray scattering -- SB sodium benzoate -- SBS poly(styrene-butadiene-styrene) -- SEBS styrene ethylene butylene styrene -- SEM scanning electron microscopy -- SEP styrene-block-ethylene-ran-propylene -- SiO2 silica -- SMA2 styrene-maleic anhydride copolymers -- SSA successive self-nucleation and annealing -- SCB short chain branches -- t time -- t0 the induction time -- T temperature -- TA crystallization temperature after nucleation from type A heterogeneity -- Tannealing temperature at which annealing occurs -- TB crystallization temperature after nucleation from type B heterogeneity -- Tc crystallization temperature -- TCB crystallization temperature of the B peak -- Tiso temperature of the isothermal experiment -- Tg glass transition temperature -- Tm melting temperature -- Tm0 equilibirum melting temperature -- TODT order disorder transition temperature -- Ts self-nucleation temperature -- TSN highest temperature at which self-nucleation temperature is observed temperature -- T∞ temperature where chain mobility ceases -- TEM transmission electron microscopy -- U* the activation energy for chain diffusion -- ULDPE ultra low density poly(ethylene) -- UV ultraviolet -- V droplet volume -- Vc being the relative volumetric transformed fraction -- VD average droplet volume -- VLDPE very low density poly(ethylene) -- Xc crystallinity degree -- Xt crystallinity at different crystallization times -- X∞ final crystallinity -- ZN-PP Ziegler‐Natta PP -- 1τ50% the inverse of the half-crystallization time -- ΔG* free energy for the formation of a nucleus of critical size -- ΔH(t) crystallization enthalpy at time t -- ΔHCA crystallization enthalpy of peak A -- ΔHCB crystallization enthalpy of peak B -- ΔHTOT is the final crystallization enthalpy at the adopted crystallization temperature -- Δσ interfacial free energy difference parameter -- ΔσA interfacial free energy difference parameter for A type heterogeneity -- ΔσB interfacial free energy difference parameter for B type heterogeneity -- ΔT undercooling -- ΔTA supercooling corresponding to the crystallization from A type heterogeneity -- ΔTB supercooling corresponding to the crystallization from B type heterogeneity -- σmc interfacial free energy between the polymer melt and the crystal -- σms interfacial free energy between the polymer melt and the solid substrate -- σcs interfacial free energy between the crystal and the solid substrate -- φSiO2 silica content -- φfiller filler content -- μm micrometer -- vd volume of the phase -- χ Flory Huggins interaction parameter between the blocks forming the copolymer; Polymers -- Periodicals; Polymerization -- Periodicals; Polymers -- Industrial applications -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.progpolymsci.2021.101376
• Languages: English
• ISSNs: 0079-6700

Abstract

Highlights: FC occurs when a polymer is divided in a large number of microdomains (MDs). When the number of heterogeneities in bulk equals the number of MDs, FC occurs. The injection of nucleating agents or self-nuclei in every MD eliminates FC Nucleation goes from heterogeneous to homogeneous by increasing confinement. Crystallization kinetics can change from sigmoidal to first order by confinement. Abstract: The crystallization of heterogeneously nucleated bulk polymers typically occurs in a single exothermic process, within a narrow temperature range, i.e., a single exothermic peak is detected by differential scanning calorimetry when the material is cooled from the melt. However, when a bulk semicrystalline polymer is subdivided or dispersed into a multitude of totally (or partially) isolated microdomains (e.g., droplets or cylinders), in number comparable to that of commonly available nucleating heterogeneities, several separated crystallization events are typically observed, i.e., fractionated crystallization. This situation is often found for the minor crystallizable component in immiscible blends. When the bulk polymer is dispersed into a number of microdomains that is several orders of magnitude higher than the available number of heterogeneities within it, most microdomains will be heterogeneity-free. In these clean microdomains the nucleation can occur by contact with the interfaces (i.e., surface nucleation) or by homogeneous nucleation inside the microdomain volume. These cases can be easily encountered in cylinders or spheres within strongly segregated block copolymers, or in infiltrated polymers within nanopores of alumina templates. In this work, a comprehensive review of the known cases of fractionated crystallization is provided. The changes upon decreasing microdomain sizes from a dominant single heterogeneous nucleation, through fractionated crystallization, to surface or homogeneous nucleation are critically reviewed. Emphasis is placed on the common features of the phenomenon across the different systems, and thus on the general conclusions that can be drawn from the analysis of representative semicrystalline polymers. The origin of the fractionated crystallization effects and their dramatic consequences on the nucleation and crystallization kinetics of semicrystalline polymers are also discussed. Graphical abstract: Image, graphical abstract