The third generation of hydroxyl-terminated aliphatic hyperbranched polyesters were end-capped with stearic acids
in which the polyesters were prepared using 1
1
1-trimethanol propane (TMP) as the core and 2
2-bis (hydroxymethyl) propionic acid (DMPA) as the branched monomer. The crystallization
melting behavior
temperature-induced variation of the conformational behavior and the packing structure of alkyl-terminated chains of the hyperbranched polyesters with different degrees of modification were investigated by wide angle X-ray diffraction (WAXD)
differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR). The influence of the terminal alkyl chains on the dynamic viscoelastic behavior of the modified hyperbranched polyesters was studied by rotational rheometer. The results showed that the crystallization of these modified hyperbranched polyesters could be attributed to ordered arrangement of the long-chain end alkanes
and the terminal alkyl chains tended to pack into hexagonal form. With the increase of degree of modification
the diffraction intensity strengthened. Double melting peaks were found in DSC heating curve. The lower melting peak was corresponding to the fusion of the imperfect crystals formed by confined terminal alkyl chains
and the higher melting peak was ascribed to the melting of the relatively well-developed crystals formed by slightly confined terminal alkyl chains. FTIR analysis conducted at different temperatures revealed that
accompanying the melting of the terminal alkyl chains crystallization
the conformation of the terminal alkyl chains of the modified hyperbranched polyesters showed no obvious transition. Upon the melting temperature
the terminal alkyl chains under confined crystallization did not emerge as completely disordered state. These hyperbranched polyesters melts might be arranged in a somewhat ordered state. With the improvement of the degree of modification
the onset of nonlinear viscoelastic region occurred at lower strains for these modified hyperbranched polyesters
and the elasticity of these modified hyperbranched polyesters increased gradually
with the phenomenon of shear-thinning behavior becoming more obvious. These phenomena
appeared in the dynamic rheological experiments
were closely related to the confined terminal alkyl chains of the modified hyperbranched polyesters.
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Study on Isothermal Crystallization Kinetics of Poly(ethylene oxide) Droplets by Fast Scanning Calorimetry
Effect of Hydrogen Bonding Interaction on Rheological Properties of Hydroxyl-terminated Hyperbranched Polyesters
CONFINED CRYSTALLIZATION AND MELTING BEHAVIOR OF POLY(ETHYLENE OXIDE) CAPPED WITH n-OCTADECYL GROUPSTHE EFFECT OF TETHERING DENSITY
CONFINED CRYSTALLIZATION OF POLY(ETHYLENE OXIDE) UNDER COPPER(Ⅱ) ION COORDINATIONDEFECT-INDUCED MELTING POINT DEPRESSION
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Related Institution
Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matter Physics, College of Physical Science and Technology, YiLi Normal University, Yining
School of Chemistry and Chemical Engineering, The State Key Laboratory of Coordination Chemistry, Nanjing University
Key Laboratory of Advanced Materials MOE, Department of Chemical Engineering, Tsinghua University
Key Laboratory of Advanced Materials MOE, Department of Chemical Engineering, Tsihuang University Beijing