jrups
|
|
Abstract: Development of new alternative materials having the superior characteristics than traditional material has become a new buzz to the researchers. One of the achievements in this field is fibre reinforced polymer composites (FRPCs). The most fascinating aspect of FRPCs is light weight but higher strength and chemical resistance. Further to obtain a biodegradable one natural fibre are taking place of synthetic fibre in the processing of NFRPCs. Researchers have done extensive research works on NFRPCs to expand it application field. But sometimes only natural fibre reinforcement cannot fulfil the design requirement. Hybridization with synthetic fibre reinforcement can significantly improve the physical and mechanical properties despite of processing parameters. Again, nanoparticle fillers are also helpful to enhance the mechanical properties. The aim of this study is to clarify the use of different types of natural fibres as reinforcement to fabricate polymer composites and their corresponding mechanical properties for particular application which will be helpful to design NFRPCs for different application. Keywords: Natural Fibre, Synthetic Fibre, Composites, Biodegradability, Mechanical Properties. |
|
|
Abstract: This paper describes an unconventional case of the repair and strengthening of the lighting pole made of reinforced concrete using the Polymer Cement Concrete (PCC) and Fiber Reinforced Polymer (FPR) systems. The damage of the element as well as causes are discussed. The concept and technology of the repair and strengthening of the reinforced concrete lighting pole are presented in detail. Keywords: Composite materials, strengthening of the structures, Polymer Cement Concrete (PCC), Fiber Reinforced Polymer (FPR). |
|
|
Abstract: Seaweed, creatures and cellulose based packaging materials are biodegradable and promising natural polymer and their films can be prepared from bio-based raw materials. This article reviews the basic information and recent developments of both seaweed, creatures, cellulose and plant based biopolymer materials as well as analyses the feasible formation of seaweed/creatures/cellulose/plant based biodegradable packaging films which possesses excellent mechanical strength and water resistance properties. Moreover, bio-based packaging films can prolong a product’s shelf life while maintaining its biodegradability. Additionally, the films show potential in contributing to the bio-economy. These type of bio-based materials exhibit interesting film-forming properties that can be used in biomedical application and for making composites for packaging. Bio-based films can be used for the large-scale applications in food packaging in place of synthetic petroleum based non-degradable packaging. Bio-based films have the potential to be used in textile and decoration paper industries also. Currently, bio packaging gains huge attention to the scientist and general people because this type packaging materials are environmental friendly products. Some of the viewpoints are highlighted for future developments and applications. Keywords: Packaging films, Seaweed, Cellulose, Plant-based materials, Biodegradibility. |
|
|
Abstract: Process parameters such as temperature and humidity, as well as formulation are the key factors in the manufacture of a polymeric component through a polyurethane prepolymer. These define the reaction kinetics, bonding and the resulting chemical interactions which determine the final characteristics of the material. One of the expected skills of polyurethane, when applied to components used in contact with water, is hydrolysis resistance. Consequently this research focused on exposure of a polymerized TDI (toluene diisocyanate) polyether polyurethane to different proportions of the curing agent, MOCA (4,4'-methylene-bis), in an environment susceptible to reactions with water at 70 °C. In this case, this material is applied in the manufacture of coil spring solid axle with trailing arms and Panhard rod suspension bushings. Mechanical tests and DSC (differential scanning calorimetry), TGA (thermogravimetry) and FT-IR (Fourier transform infrared) evaluations of the samples and prepolymer are conducted for the characterization of the different formulations, showing the negative relationship of the curing agent proportion parameters with the hydrolysis resistance. Here depolymerization of urethane and ether groups, as well as lower retention of yield stress are verified. These findings can subsidize developing predictive models for performance and lifetime of polyurethanes. Keywords: Polyurethane, prepolymer, MOCA, hydrolysis, bushing, suspension. |
|
|
Abstract: The nature of starting materials and the conditions of polyurethane (PU) preparation are regarded as the main general parameters that determine PU thermal resistance. The effect of structure and presence of additives were identified as the major general factors on this regard. Structural factors include phase microstructure, i.e. chemical structure, proportion and segregation of soft and hard segments); polyol type (petrochemical or natural oil-based); isocyanate and chain extender type and thermoplasticity of PU. Respect to the effect of additives, the incorporation of fillers is the most direct strategy to increase PU heat resistance. With respect to fiber additives, in general a positive effect is found on improving thermal resistance, although this generalization could not apply, considering the large number of different PU and environmental conditions of usage. Keywords: Polyurethane, thermal resistance, structure, additives, stability. |