In-situ elastomer composite based on fluorocarbon elastomer/liquid crystalline polymer blend

Polymer blend technology is attractive from the standpoint of both science and industry, and many combinations have been studied. Recently, the polymer blends, including liquid crystalline polymer, have been especially worthy of notice, [1,2,3]. In order to obtain materials with a high mechanical strength and moldability for use in thin molded items, we chose polyamide (PA)-liquid crystalline polymer (LCP) blends. In this study, we first measured the mechanical properties, then studied the features of the polymer structure. We also examined the relationship between morphology and mechanical properties. As a result, we found that the mechanical properties of the blends depended largely on blend morphology, and that mechanical strength increased as blend compatibility increased. On the other hand, we also found that the blends showed compatible and microheterogeneous dispersion at less than 25 wt% LCP, while at more than 30 wt% LCP, blends tended to show twophase separation.

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correlations of mechanical properties and microstructural parameters in annealed drawn film of liquid crystalline polymer in situ reinforced PP

e-Polymers ◽

10.1515/epoly.2011.11.1.851 ◽

2011 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Sayant Saengsuwan

Keyword(s):

Mechanical Properties ◽

Annealing Time ◽

Crystalline Phase ◽

Molecular Orientation ◽

Liquid Crystalline Polymer ◽

Liquid Crystalline ◽

Crystalline Polymer ◽

Relative Level ◽

Microstructural Parameters

AbstractDrawn composite thin film based on thermotropic liquid crystalline polymer (TLCP) and polypropylene (PP) was annealed at 130 °C at different times. The influence of annealing time on microstructural and mechanical properties of the composite film has been studied. The correlation in mechanical properties and their microstructural parameters has also been investigated. X-Ray diffraction results reveal that the smectic mesophase transforms progressively into the monoclinic phase as annealing time is increased. Consequently, the true crystallinity (Xc), crystal thickness (L) as well as relative level of molecular orientation of PP crystalline phase in the annealed TLCP/PP films are increased significantly. Also, the TLCP fibrils have no influence on the microstructure of PP crystalline phase. The apparent crystallinity (Xc,a) of PP phase evaluated by DSC also increase significantly with annealing time. As a result, the increases of these microstructural parameters coupled with the reinforcement of TLCP fibrils could be contributed directly to the remarkable enhancement of mechanical properties of the annealed TLCP/PP film in both machine (MD) and transverse (TD) directions. The correlation of moduli with microstructural parameters (Xc, Xc,a and L) exhibits nonlinear relations. However, the relative level of molecular orientation is a more suitable parameter to correlate with the improvement of mechanical properties of the annealed TLCP/PP film. Finally, this work presents that the mechanical properties of the TLCP in situ reinforced thermoplastics can be significantly enhanced via a simple thermal treatment.

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