Thursday, 23 January 2020 07:27

Applied Sciences grants Shanaz H. A. Al Sormeeri M.Sc on thesis " Preparation of nanocomposite building materials "

The student, Shanaz H.Ahmed, obtained a master’s degree for her thesis entitled "Preparation of nanocomposite polymers as building materials" in the field of materials science.

The discussion committee consisted of Dr. Waham M. Hamid, chairman of the committee, Dr. Hana J. Kazem, Ban A. Youssef, as members and Dr. Rana M. Salih as supervisor.

 This work aims to enhance acoustic and thermal insulation properties for polymeric composite by adding nanoclay and rock wool as reinforcement materials with different ratios.  A polymer blend of (epoxy+ polyester) as matrix materials was used, and hand lay-up technique was used to manufacture the castings. Epoxy and polyester were mixed in different weight ratios (50:50, 60:40, 70:30, 80:20, and 90:10) wt. % of (epoxy: polyester) respectively. The optimum mixing ratio (OMR) was decided upon the highest value of impact test carried out on the blends of the above mentioned ratios, which showed that the (80:20)wt.% epoxy: polyester respectively had the highest impact strength value, hence was selected as a matrix for the composite.Nano clay (Kaolinite) with ratios (5 and 7.5% ) wt.% , also hybrid reinforcement materials involving (Kaolite 5 & 7.5 % wt.% + 10% volume fraction of rockwool ) were added as reinforcement materials to the optimum sample.

The results show that the addition of nanoclay in a percentage of 7.5 wt.% Leads to the highest sound insulation, such that the sound intensity for low frequencies was 99.8 dB, reaching to 101 dB at high frequencies (10000 Hz), suggesting much lower values than the unreinforced blend, of which the sound intensity started from 107.2 dB to 108.7 for the same range of frequencies.

Thermal conductivity results showed that the composite with 7.5 % wt. has the lowest value (about 0.443 W/m.°C). The result of water Absorption showed that the diffusivity varied according to the type of material and its temperature. Mechanical properties (bending behavior, compressive strength, impact strength and flexural strength) were studied for these specimens. The results showed that the blend reinforced with nano clay in a weight fraction 7.5% and hybridized with rockwool volume fraction 10% had the lowest deflection and the highest value of Young’s modulus (1889.49)MPa in bending, while blend reinforced with 5%wt. nanoclay and 10%vol. rockwoolshowed the highest value of compressive strength (396.95) MPa. The reinforcement with nanoclay reduced the impact strength, such that the lowest impact strength was 0.0055KJ/m2 for (blend+5% nanoclay). The results of flexural test showed that the (polyester+ epoxy) blend have the highest value of flexural strength(57.4MPa). The reinforcement with 5%wt. fraction of nanoclay and 10%vol. fraction of rockwool have led to a reduction in flexural strength to the lowest value, which was 16.53 MPa.

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