Short Glass Fibers (short + glass_fiber)

Distribution by Scientific Domains


Selected Abstracts


Polymerization compounding composites of nylon-6,6/short glass fiber

POLYMER COMPOSITES, Issue 4 2003
Wei Feng
Nylon-6,6 was grafted onto the surface of short glass fibers through the sequential reaction of adipoyl chloride and hexamethylenediamine onto the fiber surface. Grafted and unsized short glass fibers (USGF) were used to prepare composites with nylon-6,6 via melt blending. The glass fibers were found to act as nucleating agents for the nylon-6,6 matrix. Grafted glass fiber composites have higher crystallization temperatures than USGF composites, indicating that grafted nylon-6,6 molecules further increase crystallization rate of composites. Grafted glass fiber composites were also found to have higher tensile strength, tensile modulus, dynamic storage modulus, and melt viscosity than USGF composites. Property enhancement is attributed to improved wetting and interactions between the nylon-6,6 matrix and the modified surface of glass fibers, which is supported by scanning electron microscopy (SEM) analysis. The glass transition (tan ,) temperatures extracted from dynamic mechanical analysis (DMA) are found to be unchanged for USGF, while in the case of grafted glass fiber, tan , increases with increasing glass fiber contents. Moreover, the peak values (i.e., intensity) of tan , are slightly lower for grafted glass fiber composites than for USGF composites, further indicating improved interactions between the grafted glass fibers and nylon-6,6 matrix. The Halpin-Tsai and modified Kelly-Tyson models were used to predict the tensile modulus and tensile strength, respectively. [source]


Interfacial strength in short glass fiber reinforced acrylonitrile-butadiene-styrene/polyamide 6 blends

POLYMER COMPOSITES, Issue 3 2010
Nihat Ali Isitman
The purpose of this study is to derive the apparent interfacial shear strength of short glass fiber reinforced acrylonitrile-butadiene-styrene/polyamide 6 (PA6) blends with different PA6 contents. Tensile stress-strain curves and fiber length distributions are utilized within a continuum micromechanics approach which involves a unified parameter for fiber length distribution efficiency represented as a function of strain. The unique combination of predicted micromechanical parameters is capable of accurately reproducing the mechanical response of the composite to applied strain. In this way, the influence of PA6 on interfacial zone is revealed by outcomes of the predictive method and validated by scanning electron microscopy observations. Favored intermolecular interactions in presence of PA6 chains result in the formation of a PA6 sheathing layer on glass fiber surfaces which in turn causes a drop in the apparent interfacial shear strength. The reason behind is shown to be the shift of the fracture zone from fiber/matrix interface to sheathing layer/matrixinterphase. POLYM. COMPOS., 2010. 2009 Society of Plastics Engineers [source]


Impact behavior of a short glass fiber reinforced thermoplastic polyurethane

POLYMER COMPOSITES, Issue 3 2000
J. Jancar
The temperature dependence of critical strain energy release rate (Gc,) and standardized Charpy notched impact strength (CNIS) were measured for a thermoplastic polyurethane (TPUR) reinforced with 30 wt% of short glass fibers (SGF) over a temperature interval ranging from ,150C 23C (RT) at two strain rates, 70 and 150 s,1, respectively. Fractographic observation of fracture planes was used to qualitatively assess the fracture modes and mechanisms. Adhesion between the reinforcement and the matrix was excellent and the integrity of the fiber-matrix interfacial contact was relatively insensitive to exposure to hydrolysis during the immersion in boiling water for 100 hours. At temperatures above ,30C, there was a large extent of plastic deformation in the vicinity of crack planes while at temperatures below ,50C, the extent of plastic deformation was substantially reduced. This resulted in a change in the major energy dissipation mechanism and led to a decrease of both CNIS and Gc, values for SGF/TPUR composites. It was suggested that the plastic deformation of TPUR matrix in the immediate vicinity of glass fibers was the primary source of energy dissipation at temperatures above ,30C, while the friction and fiber pull-out was the main dissipative process below ,50C. Over the whole temperature interval investigated, greater Gc, values were obtained at higher strain rate of 150 s,1, without any significant change in the fractographic patterns observed on the fracture planes. The CNIS/Gc, ratio, used to assess suitability of CNIS for comparison of materials, changed with temperature substantially suggesting that the functional dependences of CNIS and Gc, on temperature differ substantially. Hence, CNIS data do not provide a reliable base for material selection and for design purposes in this case. [source]


Influence of Reactice Processing on the Properties of PP/Glass Fiber Composites Compatibilized with Silane

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 4 2006
Afonso H. O. Felix
Abstract Summary: Composites of PP reinforced with 20 wt.-% of short glass fibers were prepared by extrusion using VTES as a coupling agent. The addition of VTES was performed via in-situ functionalization of PP and by a two-step process in which PP was functionalized before the composite preparation. The obtained samples were characterized using rheometry, mechanical tests and microscopy. Both processes allowed the fiber/matrix interaction to increase. It was found that the VTES content affected the viscosity of the system by means of three different mechanisms: reduction of , -scission reactions, decrease of fiber sliding and plasticizing effect on the matrix. Whereas the first two mechanisms increased the viscosity of the final composite after unreacted VTES removal, the third one reduced the viscosity during the process and contributed to fiber-length preservation. The effects of VTES and peroxide contents on the Young's modulus were closely related to their effects on the final fiber length, indicating the effectiveness of using VTES as a coupling agent. Comparison between in-situ functionalization and the two-step process with prefunctionalization showed that in-situ functionalization led to a lower degree of chain breakage, even when it was performed in the presence of peroxide. Scanning electron micrographs of PP/glass fiber composite prepared without coupling agent. [source]


Polymerization compounding composites of nylon-6,6/short glass fiber

POLYMER COMPOSITES, Issue 4 2003
Wei Feng
Nylon-6,6 was grafted onto the surface of short glass fibers through the sequential reaction of adipoyl chloride and hexamethylenediamine onto the fiber surface. Grafted and unsized short glass fibers (USGF) were used to prepare composites with nylon-6,6 via melt blending. The glass fibers were found to act as nucleating agents for the nylon-6,6 matrix. Grafted glass fiber composites have higher crystallization temperatures than USGF composites, indicating that grafted nylon-6,6 molecules further increase crystallization rate of composites. Grafted glass fiber composites were also found to have higher tensile strength, tensile modulus, dynamic storage modulus, and melt viscosity than USGF composites. Property enhancement is attributed to improved wetting and interactions between the nylon-6,6 matrix and the modified surface of glass fibers, which is supported by scanning electron microscopy (SEM) analysis. The glass transition (tan ,) temperatures extracted from dynamic mechanical analysis (DMA) are found to be unchanged for USGF, while in the case of grafted glass fiber, tan , increases with increasing glass fiber contents. Moreover, the peak values (i.e., intensity) of tan , are slightly lower for grafted glass fiber composites than for USGF composites, further indicating improved interactions between the grafted glass fibers and nylon-6,6 matrix. The Halpin-Tsai and modified Kelly-Tyson models were used to predict the tensile modulus and tensile strength, respectively. [source]


Impact behavior of a short glass fiber reinforced thermoplastic polyurethane

POLYMER COMPOSITES, Issue 3 2000
J. Jancar
The temperature dependence of critical strain energy release rate (Gc,) and standardized Charpy notched impact strength (CNIS) were measured for a thermoplastic polyurethane (TPUR) reinforced with 30 wt% of short glass fibers (SGF) over a temperature interval ranging from ,150C 23C (RT) at two strain rates, 70 and 150 s,1, respectively. Fractographic observation of fracture planes was used to qualitatively assess the fracture modes and mechanisms. Adhesion between the reinforcement and the matrix was excellent and the integrity of the fiber-matrix interfacial contact was relatively insensitive to exposure to hydrolysis during the immersion in boiling water for 100 hours. At temperatures above ,30C, there was a large extent of plastic deformation in the vicinity of crack planes while at temperatures below ,50C, the extent of plastic deformation was substantially reduced. This resulted in a change in the major energy dissipation mechanism and led to a decrease of both CNIS and Gc, values for SGF/TPUR composites. It was suggested that the plastic deformation of TPUR matrix in the immediate vicinity of glass fibers was the primary source of energy dissipation at temperatures above ,30C, while the friction and fiber pull-out was the main dissipative process below ,50C. Over the whole temperature interval investigated, greater Gc, values were obtained at higher strain rate of 150 s,1, without any significant change in the fractographic patterns observed on the fracture planes. The CNIS/Gc, ratio, used to assess suitability of CNIS for comparison of materials, changed with temperature substantially suggesting that the functional dependences of CNIS and Gc, on temperature differ substantially. Hence, CNIS data do not provide a reliable base for material selection and for design purposes in this case. [source]