Path-dependent morphologies of a diblock copolymer of polystyrene/hydrogenated polybutadiene

Cohen, Robert E.; Cheng, Panpan; Douzinas, Konstadinos C.; Kofinas, Peter; Berney, C. V.

doi:10.1021/ma00203a055

Cited by 130 publications

(117 citation statements)

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“…Similar conclusion has been confirmed in literature. Sakurai et al 23 and Cohen et al 24 speculate that the structure is kinetically trapped and could not attain a final equilibrium state when the crystallization process is observed by a non-crystallizable component with high Tg. Pizzoli et al concluded that the linear growth rate of spherulite is reduced by 2.5 orders of magnitude as a high Tg component reaches 50% by weight.…”

Section: Resultsmentioning

confidence: 99%

Crystallization and Melting Behavior of Nylon 66/Poly(ether imide) Blends

Lee

Choi

et al. 1998

Polym J

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ABSTRACT:Isothermal crystallization and melting behavior of nylon 66 and its blends with poly(ether imide) (PEI) were investigated by differential scanning calorimetry. Crystallization kinetics such as overall rate constant Z and index n were calculated according to Avrami approach. Crystallization in the blend was retarded with respect to that of pure nylon 66 by incorporation of PEI with high glass transition temperature (T.). The lowest growth rate of the spherulites was observed in the blends containing 10 and 15wt% fraction of PEI. A transition temperature where positively birefringent spherulites disappear and negative birefringent spherulites develop was measured by thermal analysis. The transition temperature increased with content of PEI in the blends. A suitable range of isothermally crystallization temperatures, 238.5-246°C, is suggested for determining the equilibrium melting points by means of Hoffman-Weeks approach.KEY WORDS Crystallization Behavior / Melting / Polymer Blend / Nylon 66/Poly(ether imide) / Poly(ether imide), PEI, (poly(2,2'-bis(3,4-dicarboxyphenoxy)phenyl propane)-2-phenylene bisimide), is a relatively new high performance material with the repeat unit:It is a thermally stable, non-crystallizable and soluble thermoplastic manufactured by General Electric Co. Key properties of PEI are excellent high temperature resistance, toughness, good dielectric properties, low flammability, and high resistance to radiation and deformation under load at elevated temperatures. In particular, PEI combines relatively low production cost with appreciable physical properties. 1 -3 Some basic research on the blends of PEI with thermotropic liquid crystalline polymers, 4 polyetheretherketone, 5 polyethersulfone, 6 and polybenzimidazole 7 has been carried out.Aliphatic polyamides are extensively used in the manufacture of automobile parts, engineering products, and textile fibers. Among various polyamides, nylon 66 and nylon 6 are commercially important polyamides. Nylon 66 is a crystallizable material with relatively high mechanical properties, low cost, and low melting viscosity. Blending nylon 66 with a variety of polymers has generated considerable interest because this is an easy way of tailoring nylon 66 to suit specific end uses. Sometimes, it made blends of nylon 66 with novel mechanical performance and excellent processing properties. Significant improvement in processing properties of PEI can be achieved without a consequent decrease in the mechanical properties by blending a small amount of nylon 66 with PEL The mechanical and heat resistant properties of nylon 66 increase remarkably by adding PEI as a minor component. Thus, blending the two polymers seems most attractive in terms of both processability and performance improvement.Numerous works have been reported on polyamides regarding melting behavior, 8 • 9 crystal structures, 10 , 11 spherulitic morphologies, 12 • 13 as well as the reorganization of crystals on heating, 14 but study of crystallization and melting behavior of nylon blends,...

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Section: Resultsmentioning

confidence: 99%

Crystallization and Melting Behavior of Nylon 66/Poly(ether imide) Blends

Lee

Choi

et al. 1998

Polym J

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“…This makes the crystallizable block copolymers representative systems having confined crystallization behavior, especially in the strong segregation regime [52]. Confined crystallization has been widely observed in the diblock copolymers having double crystalline blocks, such as PEO-b-PCL [112][113][114][115][116], PLLA-b-PEO [117][118][119][120][121][122], PLLA-b-PCL [123][124][125], poly(p-dioxanone) (PPDX)-b-PCL [126][127][128], polyolefin-based block copolymers [129][130][131][132][133][134][135], and so on. The confined crystallization kinetics and crystalline morphology of such block copolymers have been extensively studied.…”

Section: Crystalline Morphology Of Polymer Segments Confined In Blockmentioning

confidence: 99%

Crystalline and Spherulitic Morphology of Polymers Crystallized in Confined Systems

Xie

Bao

et al. 2017

Crystals

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Due to the effects of microphase separation and physical dimensions, confinement widely exists in the multi-component polymer systems (e.g., polymer blends, copolymers) and the polymers having nanoscale dimensions, such as thin films and nanofibers. Semicrystalline polymers usually show different crystallization kinetics, crystalline structure and morphology from the bulk when they are confined in the nanoscale environments; this may dramatically influence the physical performances of the resulting materials. Therefore, investigations on the crystalline and spherulitic morphology of semicrystalline polymers in confined systems are essential from both scientific and technological viewpoints; significant progresses have been achieved in this field in recent years. In this article, we will review the recent research progresses on the crystalline and spherulitic morphology of polymers crystallized in the nanoscale confined environments. According to the types of confined systems, crystalline, spherulitic morphology and morphological evolution of semicrystalline polymers in the ultrathin films, miscible polymer blends and block copolymers will be summarized and reviewed.

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“…21 Obtaining detailed control over microphase morphology remains, however, notoriously difficult. 22 Annealing, 23 external fields, 24 strain compression, 25 addition of fullerenes, 8,26 or complex chemical environments 27 are often necessary to order diblock copolymers, for instance. Understanding how to tune and stabilize microphases is essential to broadening their material relevance, yet experimental systems provide limited microscopic insights.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo approach for studying microphases applied to the axial next-nearest-neighbor Ising and the Ising-Coulomb models

Zhang

2011

Phys. Rev. B

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The equilibrium phase behavior of microphase-forming systems is notoriously difficult to obtain because of the extended metastability of their modulated phases. In this paper we present a systematic simulation methodology for studying layered microphases and apply the approach to two prototypical lattice-based systems: the three-dimensional axial next-nearest-neighbor Ising (ANNNI) and Ising-Coulomb (IC) models. The method involves thermodynamically integrating along a reversible path established between a reference system of free spins under an ordering field and the system of interest. The resulting free-energy calculations unambiguously locate the phase boundaries. Simple phases are not found to play a particularly significant role in the devil's flowers and interfacial roughening plays at most a small role in the ANNNI layered regime. With the help of generalized order parameters, the paramagnetic-modulated critical transition of the ANNNI model is also studied. We confirm the XY universality of the paramagnetic-modulated transition and its isotropic nature.

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Path-dependent morphologies of a diblock copolymer of polystyrene/hydrogenated polybutadiene

Cited by 130 publications

References 4 publications

Crystallization and Melting Behavior of Nylon 66/Poly(ether imide) Blends

Crystallization and Melting Behavior of Nylon 66/Poly(ether imide) Blends

Crystalline and Spherulitic Morphology of Polymers Crystallized in Confined Systems

Monte Carlo approach for studying microphases applied to the axial next-nearest-neighbor Ising and the Ising-Coulomb models

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