Molecular and topological structures in polyester block copolymers

Песецкий, С. С.; Jurkowski, B.; Ol’khov, Yu. A.; Ol’khova, O. M.; Storozhuk, I. P.; Mozheiko, U.M

doi:10.1016/s0014-3057(01)00120-3

Cited by 45 publications

(24 citation statements)

References 19 publications

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“…It is thought that this amorphous phase is homogeneous, resulting in the description of the copoly(ether ester)s by a twophase model: a crystalline PBT phase and a homogeneous amorphous PTMO/noncrystalline PBT phase, both being co-continuous. [1][2][3]6 However, more recent studies using solid-state NMR 14 and thermomechanical analysis 15 demonstrate that the amorphous phase is not homogeneous but consists of a PTMO-rich phase and a PBT/PTMO mixed phase.…”

Section: Introductionmentioning

confidence: 99%

Morphology, Surface Structure, and Elastic Properties of PBT-Based Copolyesters with PEO-b-PEB-b-PEO Triblock Copolymer Soft Segments

et al. 2002

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The elasticity of commonly known poly(butylene terephthalate)-poly(tetramethylene oxide) (PBT-PTMO)-based copoly(ether ester)s is increased by replacement of PTMO soft segments with poly-(ethylene oxide)-block-poly(ethylene-stat-butylene)-block-poly(ethylene oxide) (PEO-b-PEB-b-PEO) triblock copolymer soft segments containing a nonpolar middle block based on hydrogenated polybutadiene (PEB). The incorporation of this strongly incompatible PEB block resulted in the aimed increased phase separation between the PBT hard blocks and the soft segment phase, leading to a disperse PBT phase and hence to an increased elasticity. Dynamic shear experiments in combination with small-angle X-ray scattering revealed that crystallization of the PBT hard segments occurs from a microphase-separated melt. The resulting dispersed PBT hard phase in these materials is shown using transmission electron microscopy (TEM) and scanning force microscopy (SFM), whereas the increased elasticity is demonstrated using mechanical characterization. Hysteresis measurements reveal that the plastic deformation after recovery from 100% strain is only 1-6% (depending on composition) for the new PEB-containing copolyesters compared to 33% for a PBT-PTMO-based copoly(ether ester). The combination of results obtained with differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) points toward a complex morphology for the PEB-containing copolyesters. Five different phases exist: a crystalline pure PBT phase, pure amorphous PEB, and PBT phases and a PEO-rich phase besides an amorphous mixed PEO/PBT phase.

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Section: Introductionmentioning

confidence: 99%

Morphology, Surface Structure, and Elastic Properties of PBT-Based Copolyesters with PEO-b-PEB-b-PEO Triblock Copolymer Soft Segments

et al. 2002

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“…PE, as in any rigid-chain polymer and oligomer [13], can be calculated by the technique of block-by-block averaging, as in the case of any rigid-chain polymer:…”

Section: Resultsmentioning

confidence: 99%

Effect of Gamma-Radiation on the Molecular-Topological Structure of Polyethylene

Allayarov

Смирнов

et al. 2005

High Energy Chem

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The molecular-topological structure of powdered high-density polyethylene (PE) after its compression under an optimized pressure and γ -radiolysis was first analyzed. A semicrystalline structure composed of one amorphous block and three crystalline modifications was formed with different rates and different melting onset temperatures in unirradiated PE and in PE irradiated to a dose of 5.5 Mrad. This structure was retained to 242 Mrad; after such a dose, the amorphous block completely disappeared. The net crystallinity of PE at a dose of 5.5 Mrad reached a minimum value but was close to 100 wt % in the initial state or after irradiation to 242 Mrad.

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“…The TMS features and the procedures for calculating the thermome chanical curves (TMCs) of semicrystalline or network polymers and copolymers are detailed in [18][19][20][21].…”

Section: Methodsmentioning

confidence: 99%

The effect of γ-irradiation on laser ablation of polyketone

et al. 2013

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Results of a pioneering study of the effect of laser radiation in vacuum on the surface of a polyke tone (alternating terpolymer of ethylene, propylene, and carbon monoxide, POK) plate are presented. It has been found that laser beam irradiation leads to the surface heating of the plate, its melting, and the formation of a characteristic surface microrelief, an ablation crater, from which the gas flow of the ablation plume carries away products that are deposited on surfaces outside the laser beam area to form a coating with a chemical composition close to that of the substrate POK. A rim grows from molten POK around the crater. The melting point of the crystalline modification (377 K), the molecular flow temperature (427 K), and the molecular weight of the coating (25560) are much lower than those of the initial POK (464 K, 477 K, and 159200, respectively), thereby indicating laser induced chain degradation of POK. The preliminary γ irradiation of POK to a dose of 100 kGy enhances its laser ablation rate.

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Molecular and topological structures in polyester block copolymers

Cited by 45 publications

References 19 publications

Morphology, Surface Structure, and Elastic Properties of PBT-Based Copolyesters with PEO-b-PEB-b-PEO Triblock Copolymer Soft Segments

Morphology, Surface Structure, and Elastic Properties of PBT-Based Copolyesters with PEO-b-PEB-b-PEO Triblock Copolymer Soft Segments

Effect of Gamma-Radiation on the Molecular-Topological Structure of Polyethylene

The effect of γ-irradiation on laser ablation of polyketone

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