Aim:The purpose of this in vitro research is to chemically characterize polymethyl methacrylate (PMMA) processed with 10% and 20% (v/v) tricyclodecane dimethanol diacrylate (TCDDMDA) comonomer. It also aimed to assess the degree of conversion (DC) and glass transition temperature (T g ) of the formed copolymers. Materials and methods: The experimental groups were processed with the TCDDMDA comonomer (10% and 20% v/v), whereas the control group was processed only with the methyl methacrylate monomer. The copolymerization was studied by nuclear magnetic resonance (NMR) spectroscopy. The surface characteristics and composition (wt%) were studied by field-emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy (cuboidal specimen; 5 mm × 5 mm × 3 mm), respectively. The DC and T g of the formed copolymers (powdered form) were analyzed by Fourier transform infrared spectroscopy and differential scanning calorimetry, respectively. One-way analysis of variance with post hoc Bonferroni test was used to compare the mean values of DC% and T g among the groups. Results: The newly formed copolymer [P(MMA-co-TCDDMDA)] was chemically characterized by NMR and FESEM-EDX. The DC and T g of the experimental groups were higher than the control. Tricyclodecane dimethanol diacrylate at 20% (v/v) concentration showed the highest DC and T g . Conclusion:The addition of TCDDMDA comonomer improved the DC and T g of the formed copolymer. Clinical significance: The P(MMA-co-TCDDMDA) copolymer is expected to improve the mechanical properties and biocompatibility of the denture base acrylic resin. This would result in improved denture quality and durability, thereby, imparting a better quality of life to the geriatric population.

Background: Polymerization shrinkage is an innate characteristic of thermo-polymerized denture base acrylic resin. Volumetric shrinkage is still a problem, although myriad material modifications. Ring-opening oxaspiro monomers have promising volumetric expansions of about 7%. These monomers have diminished the shrinkage in dental filling resins through copolymerization (CP). However, their CP with denture base resins is not reported yet. Purpose: The aim is to confirm the CP of an oxaspiro monomer with methyl methacrylate (MMA) by radical-cationic hybrid polymerization and to assess the degree of conversion (DC) of the formed copolymer. Materials and Methods: The oxaspiro monomer was synthesized by a transesterification reaction. The study groups were based on the composition and thermo-polymerization method. The control and E1 groups were thermo-polymerized in water-bath, whereas the E2 group in a laboratory autoclave. Both E1 and E2 groups contained the oxaspiro monomer and cationic initiator. E2 group had an additional radical initiator. The CP and DC were confirmed and assessed by infrared spectroscopy. Results: Accentuation of carbonyl peak, the disappearance of the spiro-carbon peak, and the appearance of ether linkages in experimental groups confirmed the ring-opening. E2 group had the highest DC. Conclusion: The oxaspiro monomer successfully copolymerized with MMA and had good DC.

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Renewable source of energy is the best form of consumable energy that can be harnessed from the earth's available resources in a sustainable manner. Nuclear energy obtained from nuclear fission reactions from the nuclear reactors is an example of such kind of energy, but deeply requires caution in the handling of operations. Leakage of fast moving high energy neutrons creates harm to both the environment and mankind and hence should be shielded from all available means. One such effort to shield this high energy radiation is by using boron carbide infused cement mortar that can be used for plastering and other similar applications in the construction of nuclear reactors. The strength and performance based characteristics of such type of mortar are studied and improved by adding super-plasticiser and pozzolanic materials like microsilica and metakaolin. Also durability studies like alkalinity, water absorption etc are done to analyse the lifetime of the design mix. EDS and SEM analysis were also performed extensively to study the microstructure of the casted specimen and to analyse the elemental composition cum distribution (by EDS mapping) for the calculation of the neutron attenuation of the specimen mix. Based on these an optimum combination is arrived at for practical applications that has a desirable strength, performance, durability and neutron shielding property.