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Preparation, Structure and Properties of Nylon 6/Elastomer/MMT Ternary Composties

Author: YuXiaoHong
Tutor: LiYingChun
School: University of North
Course: Polymer Chemistry and Physics
Keywords: Nylon 6 Montmorillonite Elastomer Nanocomposites Mechanical Properties Rheological behavior Crystallization Behavior
CLC: TB383.1
Type: Master's thesis
Year: 2011
Downloads: 79
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Abstract

This thesis PA6 resin matrix, EPDM and EPDM-g-MAH elastomer and nano-montmorillonite as filler, prepared by PA6 / elastomer / MMT ternary nanocomposites by melt intercalation. Synergistic enhancement of the relationship of the structure and properties of toughened nylon 6 composite system morphology the montmorillonite and EPDM-g-MAH/EPDM modifier system around the high-performance and theoretical studies more in-depth exploration and analysis, for the development and application of high-performance nylon composite matting, and its study of the structure and mechanical properties of the rheological behavior of melting and crystallization behavior research. The main contents are as follows:. EPDM-g-MAH/EPDM, MMT and PA6 resin as the main raw material PA6 / elastomer / Montmorillonite three yuan nanocomposites were prepared: wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM) of PA6 and PA6 / elastomer / Montmorillonite Nanocomposites structure characterized montmorillonite content of 2%, PA6 molecules intercalated MMT When the montmorillonite content of 5% to obtain a peel-off type of the nanocomposite; its microscopic morphology study results show that: the montmorillonite content of less has little effect on the particle size of the elastomer, elastic body size smaller, when the the montmorillonite content exceeds 5%, the MMT into the elastomer to form a core-shell structure, and increase the modulus and the particle diameter of the elastic body, so that the impact toughness is reduced. With increasing the content of the elastomer, the dispersed particles is first reduced, and when the elastomer content is 20% minimum, and when the elastomer content is 25%, the dispersed phase particle size increases. The layer thickness of the composite critical brittle-ductile transition matrix 0.22μm. By the mechanical properties of the test, the study found that: reduce PA6 / elastomer / montmorillonite composite impact strength increased with increasing elastomer content, the elastomer content of 20%, the composite impact strength 54.29KJ / m ~ 2, nylon 6 / montmorillonite impact strength 5.29KJ / m ~ 2 of 10.24 times. With increasing elastomer content in the composite material tensile strength, flexural strength gradually decreased, while the elongation at break of the composite material with increasing elastomer content in first increases and then decreases in the content of the elastomer is 20% maximum ; With the increase of montmorillonite content, the impact strength of the composites first increases and then decreases when the MMT content of 2%, the impact strength of the material 54.29KJ / m ~~ pure nylon 6 impact strength 4.15KJ / m ~ 2 of 12.08 times. Sui OMMT content increases, the tensile strength, flexural strength and flexural modulus of the composite material increases. Elongation at break first and then decrease with increasing OMMT content OMMT content of 2% maximum. 2. PA6 / elastomer / Montmorillonite Nanocomposites rheological behavior research: the study found PA6 and PA6 / elastomer / MMT ternary nanocomposites are pseudoplastic fluid showed shear thinning phenomenon, and the non-Newtonian index decreases with the increase of montmorillonite content; less after the same shear rate, the PA6 / elastomer / MMT ternary nanocomposites melt viscosity first increases with the increase of montmorillonite content small, and the turning point as the temperature rises forward. In the same shear rate, with the increase in the content of the elastomer, and its apparent viscosity is successively increased, and when the elastomer content of more than 20%, the apparent viscosity is greatly reduced. The EPDM join limit the montmorillonite internal plasticization play. Organic phyllosilicate mineral content of the polymer / layered silicate composite melt viscosity, first proposed \Montmorillonite preferentially distributed in the macromolecular chains between random winding state (sponge), can play a limit the unwrapping role; montmorillonite content and to a certain extent, the random winding state macromolecular chains. filled the gap between the (sponge), montmorillonite lamellae will be distributed between the orientation unwrapping the macromolecule chain (silk), weakened the macromolecular chains intertwined macromolecular chains and MMT slippage between the layers, since the internal plasticization. The greater the shear stress, the higher the temperature, the more unwrapping orientation states (silk), random wound state (sponge) less. 3 of the melting and crystallization behavior of PA6 and PA6 / elastomer / montmorillonite nanocomposites research: studies have shown that MMT in the composite plays the role of heterogeneous nucleation, while MMT was added to make the PA6 matrix polymorph by γ crystal form into α crystal type. Classical crystallization kinetics theory of PA6 and PA6 / elastomer / MMT ternary nanocomposites crystallization kinetics study, the results showed that: Avrami equation well described PA6 and PA6 / elastomer / Montmorillonite nanocomposites Isothermal crystallization kinetics of the process. Ozawa equation and modified after Jeziorny Avrami equation is not suitable to describe non PA6 nanocomposites isothermal crystallization kinetics of the process, the Mo method for its non isothermal crystallization kinetics process. Based on the experiments, the fitting PA6 and its nanocomposites crystallization kinetics parameters. Also Hoffmann-Lauritzen theory obtained by crystallization activation energy of nonisothermal crystallization process.

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