Inexpensive Filler Research Articles

Mechanical and thermal properties of a novel composite prepared with epoxy resin and lateritic ore

Composites made from epoxy resins (ERs) are one of the important polymer groups used in different industries due to their good mechanical and thermal properties. Many attempts have been done to improve both the mechanical and the thermal properties of ER composites and to lower the cost of ER composites with addition of inexpensive fillers such as calcium carbonate, kaolin clays, silica, talc, etc. In this study novel lateritic ore (LO) filler was used in diglycidyl ether of bisphenol A‐type ER. Different addition percentages (5–20%) of both natural LO (nLO) and modified LO (mLO) into ER were tested to determine the influence on mechanical and thermal properties of newly produced composites. Surface hardness, Young's modulus, tensile strength, elongation at break, water sorption, adhesion, and thermal stability of composites were determined and were compared with pure ER. Results showed that the addition of nLO/mLO has positive effect on mechanical and thermal properties. Morphological characterization by scanning electron microscopy and structural characterization by X‐ray diffraction revealed that addition nLO/mLO distributed homogenously throughout the composites. POLYM. COMPOS. 34:1375–1381, 2013. © 2013 Society of Plastics Engineers

Epoxy composites based on inexpensive char filler obtained from plastic waste and natural resources

AbstractIn this study, plastic [polyethylene terephthalate (PET)] waste was recycled as raw material for the preparation of diglycidyl ether of bisphenol A‐type epoxy composite materials. The other inexpensive fillers used to prepare the composites were wood shavings char and pine cone char (PCC), obtained from natural resources. The thermogravimetric analysis showed that plastic waste char (PWC) and PCC can significantly improve the thermal stability of neat epoxy resin at temperatures above 300°C. The best thermal and electrical conductivity results were obtained with PWC. The residual weight of the composite with 30 wt% PWC was 69%. Surface hardness, Young's modulus, and tensile strength of the composites were higher than those with a pure epoxy polymer matrix. The composite morphology was characterized by X‐ray diffraction and scanning electron microscopy. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Crystallization behavior and mechanical properties of polypropylene/halloysite composites

In this work, halloysite nanotubes (HNTs), a new type of inexpensive filler, were used for the modification of polypropylene (PP). HNTs were first surface treated by methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium, then melt mixed with PP. Scanning electron microscope (SEM) was used to examine the dispersion of HNTs in PP matrix. Differential scanning calorimetry (DSC), polarized light microscope (PLM), dynamic melt rheometry and wide angle X-ray diffraction (WAXD) were employed to investigate the crystallization behavior of the prepared PP/HNT composites. The mechanical properties were evaluated by Instron and impact tests. SEM results revealed that HNTs could be well-dispersed in PP matrix and had a good interfacial interaction with PP, even up to a high content of 10 wt%. DSC data indicated that HNTs could serve as a nucleation agent, resulting in an enhancement of the overall crystallization rate and the non-isothermal crystallization temperature of PP. PLM showed a constant spherulite growth rate and a decreased spherulite size at given isothermal crystallization temperature, suggesting that nucleation and growth of a spherulite are two independent processes. The result obtained by dynamic melt rheometry indicated that HNTs mainly promoted nucleation and had not much influence on the growth of PP crystallization. Nevertheless, by fast cooling the samples, almost constant spherulite size can be obtained for both pure PP and PP/HNT composites due to the limited nucleation effect of HNTs on PP crystallization. WAXD showed that HNTs mainly facilitated α-crystal form of PP. Though a good dispersion of HNTs in PP matrix was observed, out of our expectation, not much enhancement on mechanical properties of PP/HNT composites had been achieved, and this could be mainly ascribed to the constant crystallinity and spherulite size of PP as well as the small length/diameter ratio of HNTs.

Gas in stems: abundance and potential consequences for tree biomechanics.

Secondary xylem of woody plants has a large volumetric proportion of gas occupying spaces that would otherwise be filled with water. We examined whether these gas-filled voids have a mechanical role by either decreasing the fresh mass the tree must support (by replacing some of the water with gas) or by providing inexpensive filler to increase stem diameter (thereby increasing the second moment of area at the expense of the modulus of elasticity and modulus of rupture). Calculations from published data show that temperate softwood species (n = 26) average 18 and 50% gas by volume for sapwood and heartwood, respectively; temperate hardwood species (n = 31) average 26% gas by volume in both the sapwood and heartwood; and tropical species (n = 52) with mixed sapwood and heartwood have 18% gas by volume. In this paper, we develop equations to show how gas affects the mechanical behavior of tree stems, and describe model results to show how gas affects mechanical stability, based on mass and stem diameters for six 34-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. For the same applied load, modeled stems in which the gas space was filled with water differed in their surface stresses by < 2% from modeled stems in the native state (partially gas-filled), indicating no practical benefit from a reduction in stem mass due to gas. A second modeling scenario compared the native state to stems in which gas was removed and stem diameters decreased (and material properties adjusted to concur with the increased wood density) to conserve mass. Removal of the gas-filled voids resulted in up to 41% higher surface stress for the same applied load, caused by a decrease in the second moment of area greater than the increase in modulus of elasticity. Trees with gas removed had higher modulus of rupture, but could withstand up to 14% lower maximum wind forces than trees in their native state, suggesting a biomechanical role for the gas if the model assumptions are valid. The gas content may, however, have evolved in response to pressures unrelated to biomechanics. We discuss some of its potential effects on sapwood physiology.

Reactor Graphites Based on Inexpensive Raw Materials

Data are presented on the performance characteristics and properties of Russian-produced graphites molded with inexpensive fillers—electrode, schistose, and pitch cokes. Replacement of petroleum coke, used earlier, by these cokes ensures performance parameters that meet the relevant specifications.

Effect of Selected Inorganic Fillers on the Processing Characteristics, Technological Properties and Flammability of Natural Rubber Vulcanizates

A wide variety of elastomer based products are commonly used for applications such as tires, gloves, tarpaulins, rubber bands, conveyor belts, floor tiles, carpet underlays, etc. Since most of these products are for indoor applications, they must have good flame resistance for safe and adequate protection. The authors have analyzed the effect of a series of inexpensive inorganic fillers on processing characteristics, technological properties and flammability of natural rubber. The flame retarding performance attributed to these fillers is compared against those of two standard and accepted flame retardants zinc borate and alumina. The results of the study show that talc and mica powder retard flammability of natural rubber satisfactorily without adversely affecting other technological properties.

Studies on Chenopodium quinoa and Amaranthus paniculatas starch as biodegradable fillers in LDPE films

Starches from newer food sources such as Amaranthus paniculatas and Chenopodium quinoa were studied for their possible role as biodegradable fillers in low density polyethylene (LDPE) films. Such starches have a unique feature of having an extremely small granule size (< 1 micron), which helps in better dispersion in polymeric films. In countries, where polymers are expensive, these starches could be used as inexpensive fillers. The effect of incorporating 3–15% corn starch, Amaranthus paniculatas and Chenopodium quinoa starch on the mechanical properties of the LDPE films was evaluated. The torque for blending of starches and LDPE was in general lower than that for LDPE alone. Incorporation of all the three starches decreased the tensile strength. Maximum decrease was observed with corn starch, and minimum decrease with Chenopodium quinoa and Amaranthus paniculatas was in between.

Composites from sawdust and unsaturated polyester

Wood is an inexpensive filler that reduces the overall cost of polymer composites, with loss in some properties (e.g., ultimate strength, elongation, and water sorption often suffer with the addition of fillers) and a gain in others (e.g., Young modulus increment, reduced weight with respect to inorganic fillers, reduced wear of the processing equipment). Sawdust of Eucaliptus saligna or calcium carbonate have been used as reinforcing fillers of an unsaturated polyester matrix. The ultimate strength, elongation, and modulus are presented as a function of the filler concentration and surface treatment. The dynamic mechanical properties were used to determine the influence of the moisture content on the performance of the final material. © 1996 John Wiley & Sons, Inc.

Composites from sawdust and unsaturated polyester

Wood is an inexpensive filler that reduces the overall cost of polymer composites, with loss in some properties (e.g., ultimate strength, elongation, and water sorption often suffer with the addition of fillers) and a gain in others (e.g., Young modulus increment, reduced weight with respect to inorganic fillers, reduced wear of the processing equipment). Sawdust of Eucaliptus saligna or calcium carbonate have been used as reinforcing fillers of an unsaturated polyester matrix. The ultimate strength, elongation, and modulus are presented as a function of the filler concentration and surface treatment. The dynamic mechanical properties were used to determine the influence of the moisture content on the performance of the final material. © 1996 John Wiley & Sons, Inc.

Preparation of controlled-release formulations of14C-labelled thiobencarb herbicide and study of their environmental behaviour

Controlled-release formulations of 14C-labelled thiobencarb herbicide were prepared in calcium alginate using kaolin as an inexpensive filler. The rates of release of the herbicide from these and from a commercial granular formulation were studied in static distilled water contained in open and closed vessels. The rate of release of the herbicide was much higher from the commercial formulation than from the controlled-release formulations. Increasing the proportion of kaolin to calcium alginate in controlled-release formulations reduced the rate of release of the herbicide. There was a significant loss of thiobencarb-related radioactivity from the water solution when the vessels containing the solutions were left uncovered and exposed to light. The loss of the herbicide seemed to be due to degradation and evaporation.