Polimetilmetakrilat/grafen nanoplatelet nanokompozitin fiziksel özellikleri

Poly (methyl methacrylate) (PMMA) is a clear, transparent thermoplastic material with good mechanical properties, high resistance to weathering and excellent heat resistance. Mechanical, thermal, electrical and radiation shielding properties of PMMA can be improved by adding several nanomaterials with excellent properties. The enhanced PMMA materials are the ideal candidates for several application areas such as medical, sensor, solar cell, electronic and aerospace areas.In this study, Graphene Nanoplatelets (GNPs) was selected as nanofiller to enhance the mechanical, thermal, electrical and radiation shielding properties of PMMA. PMMA was produced via ATRP technique. GNPs nanofiller was dispersed by in situ polymerization method because it was the most efficient method to disperse the layered GNPs nanomaterial. SEM, XRD, FTIR, TGA, hardness and compression test, ultrasonic test and gamma transmission techniques are performed to examine the changes in the characteristic properties of PMMA. SEM characterization combined with elemental mapping technique showed that GNPs nanofiller homogeneously dispersed in the PMMA polymer matrix via in situ polymerization method. Besides, the results of the ultrasound tests were supported a homogeneous structure of PMMA/GNPs nanocomposites. XRD pattern of PMMA/GNPs nanocomposites presented a pick at ~26.5° , which is corresponding to the stacking of the graphene layers at a distance of 0.34 nm. The intensity of the pick increased with the rise of the GNPs concentration. The FITR spectra of PMMA/ nanocomposite presented similar spectra with pure PMMA, indicating that interaction occurred between GNPs nanofiller and PMMA polymer matrix. TGA results showed that with the addition of 2% GNPs, the 5% weight loss temperatures shifted from 196.73°C to 243.00°C, improved by 46.27 °C. The thermal stability of PMMA enhanced significantly. With the addition of 2% GNPs the electric conductivity of PMMA improved dramatically from ~ 10-14 S/m to 0.72 S/m. In the ultrasonic test, the Shear modulus, Young's modulus and Microhardness values of pure PMMA were increased by 19.5%,16.8 %, and 14.2% respectively with the addition of 2 wt.% GNPs. Compare to the pure PMMA, with the addition of 2 wt.% GNPs the Rockwell hardness and compressive strength increased by 19.9% and 42.7% respectively. For Cs-137 and Co-60 radioisotopes, with the rise of GNPs concentration, the linear attenuation coefficients increased slightly, however, the mass attenuation coefficients decreased slowly.