Dynamic mechanical behavior of continuous multilayer composites

Gregory, Bryan; Hiltner, A.; Baer, E.; Im, James S.

doi:10.1002/pen.760270807

Cited by 25 publications

(29 citation statements)

References 15 publications

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“…The lower intensity of the PETG tan δ peak is due to stress transfer from rubbery PETG layers to glassy SAN30 layers. 35 A single broad tan δ peak is observed at an intermediate temperature for PETG/SAN30 interphase material (d 0 ) 6 nm). The peak temperature of the interphase material T g,I at 90°C is somewhat lower the glass transition temperature of a homogeneous mixture T g,h of 102°C, which is predicted by constituent additivity as…”

Section: Resultsmentioning

confidence: 96%

Polymer Interphase Materials by Forced Assembly

et al. 2005

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The interphase between two immiscible glassy polymers was probed using nanolayer films with tens to thousands of alternating layers of two polymers. Various combinations of poly(methyl methacrylate), polycarbonate, and a series of styrene-acrylonitrile copolymers were brought together by forced assembly. Continuous nanolayers with thickness on the size scale of the interphase were observed directly using atomic force microscopy. Interphase thickness was extracted from the layer thickness dependence of oxygen permeability. The interphase thickness showed the predicted dependence on the interaction parameter and correlated with interphase strength as measured with the T-peel test. Interphase specific volume, as determined by density, exhibited both positive and negative deviations from constituent additivity. The deviations correlated with the change in free volume hole size from positron annihilation lifetime spectroscopy but did not correlate directly with the parameter. The origin of the deviations was found in the nature of chain packing in the interphase, as evidenced by nonadditivity in entanglement molecular weight. The volumetric effects accounted for the glass transition behavior of the interphase material.

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Section: Resultsmentioning

confidence: 96%

Polymer Interphase Materials by Forced Assembly

et al. 2005

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“…The basic concept of damping involves the absorption of external energy through molecular friction. The layered structure of graphite is attractive for damping because of the large internal surface area involved 6–8. The relative motion between layers produces extra friction because of shear, which contributes toward additional energy dissipation 9.…”

Section: Resultsmentioning

confidence: 99%

Effect of filler geometry on viscoelastic damping of graphite/aramid and carbon short fiber‐filled SBR composites: A new insight

Praveen

Chakraborty

Jayendran

et al. 2008

J of Applied Polymer Sci

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An investigation on the effect of filler geometry/shape on the dynamic mechanical properties of polymers was conducted. The viscoelastic damping matrix chosen was SBR and the fillers chosen were graphite, aramid, and carbon short fibers. The study was conducted by taking a control base compound of 20 parts N330 carbon black-filled styrene butadiene rubber (SBR). Dynamic mechanical thermal analyzer was used to investigate the viscoelastic damping of the rubber composites at low dynamic strain levels. Compressive hysterisis at moderate degree of strain were evaluated for all the composite samples to probe into their high strain static damping properties. SEM was used to investigate the matrix-fiber interaction and distribution of the fillers. Investigations demonstrated that the matrix-filler interface plays a major role in energy dissipation. The amount of interface was analyzed by considering the half height width of tan d peak. Fiber matrix interaction parameter was calculated from the tan d max values for matrix and composite. It was observed the interaction parameter and the low strain tensile stress values register similar trend. Aramid short fibers were most effective in more energy dissipation than other fillers under consideration.

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“…Frequently, this peak has been attributed to a third phase formed by intermixing of the parent phases. We previously reported a third peak in tan 6 curves from torsional pendulum measurements on microlayers of two immiscible polymers, polycarbonate and styrene/acrylonitrile copolymer (SAN) (1). Although microlayers of PC and SAN exhibit good interlayer adhesion, the interfaces are sharp and can delaminate cleanly.…”

Section: Resultsmentioning

confidence: 99%

“…temperatures of the PC and KODAR were 150" and arious studies of the dynamic mechanical behav-V ior of polymer blends dcscribe a n anomalous damping peak at a temperature intermediate between the glass transitions of the two components ( 1 , 2). The intermediate peak is associated with co-continuity of the phases, and the suggestion has been made that it is purely mechanical in origin (1)(2)(3). As part of a n ongoing study of interdiffusion in microlayer composites of two miscible polymers (41, we undertook a comparison of glass transition measurements made by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA).…”

Section: Introductionmentioning

confidence: 99%

Origin of the intermediate damping peak in microlayer composites

Nazarenko

Haderski

Hiltner

et al. 1995

Polymer Engineering & Sci

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A comparison of glass transition temperatures measured by differential scaning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) was made using mi9crolayer composites with many alternating layers of two polymers. What appeared to be a third transition at a temperature intermediate between the glass transitions of the two components was observ ed in DMTA but not DSC. The mechanical orgin of this intermediate damping peak in the layered composites was established. The viscoelastic properties of each polymer were modelled by a spring and dashpot in series, and the composite as a parallel arrangement of two Maxwell elements. It was shown that an anomalous damping peak can appear between the glass transition temperatures when the modulus of the composite can not drop below the modulus of the glassy layers, although the viscosity of the composite continues to be defined by the viscosity of the rubbery layers in this temperature range. The intermediate damping peak may be a general feature in the dynamic mechanical behavior of co‐continuous multiphase systems including polymer blends and continuous fiber composites.

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Dynamic mechanical behavior of continuous multilayer composites

Cited by 25 publications

References 15 publications

Polymer Interphase Materials by Forced Assembly

Polymer Interphase Materials by Forced Assembly

Effect of filler geometry on viscoelastic damping of graphite/aramid and carbon short fiber‐filled SBR composites: A new insight

Origin of the intermediate damping peak in microlayer composites

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