Rama Prabha D

Bio: Rama Prabha D is an academic researcher. The author has contributed to research in topics: Epoxy & Flexural strength. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.

Evaluation of Flexural Strength of Epoxy Resin Based hybrid Composites Reinforced with Jute, Banana and Flax Natural Fibers for Bio medical applications

Abstract: In recent days the concern for the environmental pollution and the prevention of non-renewable and non- biodegradable resources has promoted research in the field of green technologies, eco friendly, non polluting materials which can maximize energy and resource savings. In the present work Jute fibres reinforced with uniaxial glass fibres in epoxy matrix, alongside Banana fibres reinforced with biaxial glass fibres in epoxy matrix and Flax fibres reinforced with biaxial glass fibres in epoxy matrix was prepared and mechanical properties were evaluated and compared for two weight fractions, the samples were prepared by using the hand lay-up process and applying pressure at room temperature. The samples were subjected to flexural testing was performed on the samples to investigate the bending properties and to suggest a material which could compete with synthetic materials and still be easily disposed.From the results, it is easily evident that flax performs better than jute and banana for the flexural strength showing higher values for flexural strength and modulus and hence this fiber can be used for biomedical applications.

Effect of Cyclotriphosphazene-Based Curing Agents on the Flame Resistance of Epoxy Resins.

Abstract: Epoxy resins are characterized by excellent properties such as chemical resistance, shape stability, hardness and heat resistance, but they present low flame resistance. In this work, the synthesized derivatives, namely hexacyclohexylamino-cyclotriphosphazene (HCACTP) and novel diaminotetracyclohexylamino-cyclotriphosphazene (DTCATP), were applied as curing agents for halogen-free flame retarding epoxy materials. The thermal properties and combustion behavior of the cured epoxy resins were investigated. The obtained results revealed that the application of both derivatives significantly increased flame resistance. The epoxy resins cured with HCACTP and DTCATP exhibited lower total heat release together with lower total smoke production compared to the epoxy materials based on conventional curing agents (dipropylenetriamine and ethylenediamine). Comparing both derivatives, the HCACTP-cured epoxy resin was found to provide a higher flame resistance. The designed novel class of epoxy materials may be used for the preparation of materials with improved flame resistance properties in terms of flame spreading and smoke inhibition.

Plant Fibers as Composite Reinforcements for Biomedical Applications

Abstract: Plant fibers possess high strength, high fracture toughness and elasticity, and have proven useful because of their diversity, versatility, renewability, and sustainability. For biomedical applications, these natural fibers have been used as reinforcement for biocomposites to infer these hybrid biomaterials mechanical characteristics, such as stiffness, strength, and durability. The reinforced hybrid composites have been tested in structural and semi-structural biodevices for potential applications in orthopedics, prosthesis, tissue engineering, and wound dressings. This review introduces plant fibers, their properties and factors impacting them, in addition to their applications. Then, it discusses different methodologies used to prepare hybrid composites based on these widespread, renewable fibers and the unique properties that the obtained biomaterials possess. It also examines several examples of hybrid composites and their biomedical applications. Finally, the findings are summed up and some thoughts for future developments are provided. Overall, the focus of the present review lies in analyzing the design, requirements, and performance, and future developments of hybrid composites based on plant fibers.

Microleakage assessment using 7th generation bonding agent with micro-hybrid composite restoration immersed in a carbonated drink – an in vitro study

Abstract: Introduction: Restored teeth in the course of chewing or when exposed to thermal stimuli may lead to sensitivity. One of the significant reasons for sensitivity is microleakage. The repercussion of unaddressed microleakage leading to secondary caries and further on. The purpose of this study was to compare the microleakage of amongst different types of restorative materials which were silver amalgam and micro-hybrid composite resin with 7th generation bonding agent. And also to examine the effect of carbonated drink on microleakage. Materials and method: Forty extracted premolars were used for the study. Class V cavities were prepared on the buccal surfaces of the teeth, 1mm above the cementoenamel junction cervico-occlusal. Twenty cavities were restored with silver amalgam, and the remaining with composite resin. Group I and Group II both comprised of 10 teeth with silver amalgam restoration and ten teeth with composite resin restoration were immersed in the carbonated drink and water respectively for 15 minutes for ten days. The teeth were later immersed in methylene blue, sectioned and evaluated under a microscope. Statistical analyses used were Fisher's exact test. Result: Silver amalgam showed highest microleakage tendency in the carbonated drink, (P > 0.05). In water, silver amalgam had the least tendency for microleakage. However, composite resin did not statistically significant microleakage in both carbonated drink and water. Conclusion: The silver amalgam restorations showed microleakage in both carbonated drink and water. The microleakage was significantly higher in the carbonated beverage. On the other hand, composite resin restoration showed microleakage neither in carbonated drink nor water.

A Study of some Morphological and Essential Oil Characteristics of Spartium junecum L.

Abstract: Spartium junecum L. was collected from Baksa in Lattakia, Syria, and studied morphologically depending on characteristics of plant life-form, flowers, leaves, fruits and seeds according to specialized floras, in addition to some characteristics of stomata types, trichomes, pollen grains and fibers that have been demonstrated by this study. The study of the leaves stomata confirmed the presence of 4 types, namely; anisocytic, isotricytic, brachyparahexacytic, and tetracytic. The type of trichomes was the same in all the studied areas, which is: non-glandular trichomes with different densities. Pollen grains were, tricolpate, triangular, the dimensions of the polar axis and equatorial axis were (35µm), and (31µm), respectively. Spartium junecum L. cellulose fibers were extracted by DiCoDe method (digestion–compression–decompression). The morphology of the obtained fibers was studied by optical microscopy (OM). The results showed that Spartium junecum L. fibers are elementary fibers arranged in bundles. The diameter of a single elementary fiber ranged from 7 to 10μm approximately, while the diameter of the whole bundle was about (50μm). The cross-sections showed an irregular polygonal shape with a very much characterized lumen. The essential oil isolated by hydrodistillation from the dried flowers of Spartium junceum L. was investigated by Gas Chromatography-Mass spectrometry (GC/MS) method. The GC/MS analysis of the oil revealed the presence of 6 constituents, of which heptacosene (28.75%), 3-ethyl-5-(2-ethylbutyl)-octadecane (22.45%), heptacosane (21.2%) and heneicosane (18.82%) were the major compounds constituting altogether almost 91.22% of the total composition.