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Properties Tests (property + test)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

In-situ pultrusion of urea-formaldehyde matrix composites.

POLYMER COMPOSITES, Issue 1 2006
II: Effect of processing variables on mechanical properties
Unidirectional fiber reinforced urea-formaldehyde (UF) composites have been prepared by the pultrusion processes. The effects of the processing parameters on the mechanical properties (flexural strength and flexural modulus, etc.) of the glass fiber reinforced UF composites by pultrusion has been studied. The processing variables investigated included die temperature, pulling speed, postcure temperature and time, filler type and content, and glass fiber content. The die temperature was determined from differential scanning calorimetry (DSC) diagram, swelling ratio, and mechanical properties tests. It was found that the mechanical properties increased with increasing die temperature and glass fiber content, and with decreasing pulling rate. The die temperature, pulling speed, and glass fiber content were determined to be 220°C, 20,80 cm/min, and 60,75 vol%, respectively. The mechanical properties reached a maximum value at 10, 5, 5, and 3 phr filler content corresponding to the kaolin, talc, mica, and calcium carbonate, respectively, and then decreased. The mechanical properties increase at a suitable postcure temperature and time. Furthermore, the properties that decreased due to the degradation of composite materials for a long postcure time are discussed. POLYM. COMPOS., 27:8,14, 2006. © 2005 Society of Plastics Engineers [source]

Effect of high-energy vibro-milling of filler on the mechanical properties of filled high-density polyethylene

POLYMER COMPOSITES, Issue 3 2003
Shaoyun Guo
The effect of high-energy mechanical milling of CaCO3 (calcium carbonate) and STC (a mixture of sericite, tridymite and cristobalite) on mechanical properties, rheological and dynamical mechanical behavior of high-density polyethylene (HDPE)/CaCO3 and HDPE/STC was studied through SEM (scanning electron microscope), DMTA (dynastic mechanical test analysis), mechanical and melt rheological properties tests. The experimental results show that addition of fillers treated by coupling agent and vibromilling to HDPE makes the impact strength of HDPE greatly increased. The impact strength of HDPE/treated CaCO3 (60/40) and HDPE/treated STC (60/40) is ca. 4 and 3 times respectively as high as that of HDPE. The SEM micrographs of impact fractured surfaces of treated fillers filled HDPE show extensive plastic deformation of HDPE matrix, indicating that the plastic deformation of matrix induced by the treated fillers is the main contribution for absorbing a great amount of impact energy. This is the reason why the impact strength of HDPE greatly increases with addition of coupling agent and vibromilling treated fillers. The intensity of , relaxation peak of HDPE in HDPE/treated CaCO3 on tan, vs. temperature curve increases and the peak shifts to higher temperature due to its stronger interface interaction as compared with that of HDPE/untreated CaCO3. [source]

Simultaneously improving the toughness, flexural modulus and thermal performance of isotactic polypropylene by ,-, crystalline transition and inorganic whisker reinforcement

POLYMER ENGINEERING & SCIENCE, Issue 2 2010
Yewen Cao
Magnesium salt (M-HOS) whisker and ,-nucleating agent were introduced into polypropylene and their effects on the crystalline structures, morphologies, mechanical properties, and thermal resistance of polypropylene (PP) were investigated. The results of wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and polar optical microscopy (POM) examinations suggested that the presence of the whisker did not cause any negative effect on the occurrence of ,-modification, and ,-phase became absolutely dominant form in ,-nucleated samples. The mechanical and thermal properties tests demonstrated that there is an excellent synergy between the ,-nucleating agent and the whisker. For PP composite containing 0.1 wt% of the ,-nucleating agent and 10 wt% of the whiskers, the Izod notched impact strength, elongation at break, flexural modulus, and heat deflection temperature were increased by 108, 194, 31, and 40%, respectively, compared with those of neat PP. By combining the toughening effect of ,,, transition with the reinforcing effect of the whisker, simultaneous improvement in toughness, flexural modulus, and thermal performance of PP was successfully achieved. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source]

Thermal properties of lightweight-framed construction components at elevated temperatures

FIRE AND MATERIALS, Issue 3 2005
Noureddine Bénichou
Abstract Fire resistance behaviour of lightweight-framed assemblies is determined by defining the thermal and structural performances of the assembly when exposed to fire. To adequately model thermal behaviour in a lightweight wood-framed assembly, thermal properties of the components of the assembly at elevated temperatures must be well defined. This paper presents results of measurements of thermal properties at elevated temperatures of construction materials commonly used to build lightweight wood-framed assemblies that were conducted at the National Research Council of Canada since 1990. The test results, in graphical form, are given as a function of temperature for thermal conductivity, specific heat, mass loss and thermal expansion/contraction for wood, gypsum and insulation. In addition, the effects of temperature on the thermal conductivity, specific heat, mass loss and thermal expansion/contraction of these materials are discussed. Finally, in addition to providing a resource of information, this paper also identifies the additional thermal property tests required to complete the matrix of information. Copyright © 2005 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. [source]