No abstract

Poly lactic acid (PLA) is a useful alternative to petrochemical commodity material used in food packaging, due to its low thermal stability and poor crystallization behaviour, it needs to improve its properties in namely terms of thermal and mechanical performance. Neat PLA was reinforced nanofiller TiO2 (titania) to improve its characteristics. Thus, the film of neat PLA and PLA nanocomposites were prepared using solvent casting and hot press methods. Diverse techniques characterized Asprepared films. To enhance the PLA miscibility, TiO2 nanoparticles were homogeneously dispersed in the PLA matrix to attain a low degree of agglomeration as explained by Field Emission Scanning Electron Microscopy (FESEM). Both XRD and differential scanning calorimetry (DSC) analyses of the reinforced nanocomposites disclosed an improvement in their crystallinity increased from 17.52 to 30.91. The dynamic mechanical analysis (DMA) indicated that the storage modulus was improved with increased TiO2 content, increased from 3.13 GPa to 3.26 GPa. Thermogravimetric analysis (TGA) results show that the addition of nanofiller improved thermal stability of the PLA nanocomposites was modified. On the other hand, the reinforced PLA nanocomposites with improved biodegradable behavior were shown to be the potential substitute of conventional petrochemical-based polymers widespread in the food packaging industries.

PVA, Starch/PVA, and Starch/PVA/sugar samples of differentconcentrations (10, 20, 30 and 40 % wt/wt) were prepared by castingmethod. DSC analysis was carried; the results showed only one glasstransition temperature (Tg) for the samples involved, which suggestthat starch/PVA and starch/PVA/sugar blends are miscible. Themiscibility is attributed to the hydrogen bonds between PVA andstarch. This is in a good agreement with (FTIR) results. Tg and Tmdecrease with starch and sugar content compared with that for(PVA). Systematic decrease in ultimate strength, due to starch andsugar ratio increase, is attributed to (PVA), which has more hydroxylgroups that made its ultimate strength higher than that forstarch/PVA, and starch/PVA/sugar blends. It is observed from wateruptake tests that the solubility time decreases with starch ratio; it isattributed to decrease in hydroxyl groups caused by PVA ratiodecrease. The inter- and inter-molecular bonds of the hydroxylgroups enhanced the solubility process of the starch/PVA blends inwater. The water immersion causes hydrogen bonds (inter andintermolecular bonds) to decompose, that increases the filmsolubility. Water absorption and capacity of degradability are mostimportant in biodegradable materials. The results suggest the samplesthat have undergone investigation, can be used for shopping, andfood packaging.The study of soil burial for the sample at (3cm) depth, and at (13cm)depth has exhibited weight loss increase with soil burial time. Thebiodegradability rapidly increases at the first (6-7) weeks; it is foundthat the weight loss at (3cm) depth is greater than that at (13cm) thatwas attributed to the differences in the availability of oxygen ratio. Itis found that PVA undergoes lowest weight loss, the weight losschanges with starch, and sugar content. In dry soil, the weight loss islower. The results proved that the biodegradation decreases with soilburial time after seven weeks of burial. It is concluded that thesamples involved are biodegradable material that can be used forpackaging applications and biologically friendly synthetic polymerblends to solve the solid waste accumulation problem.

This work describes the weathering effects (UV-Irradiation, and Rain) on the thermal conductivity of PS, PMMA, PS/PMMA blend for packaging application. The samples were prepared by cast method at different ratios (10, 30, 50, 70, and 90 %wt). It was seen that the thermal conductivity of PMMA (0.145 W/m.K), and for PS(0.095 W/m.K), which increases by PS ratio increase up to 50% PS/PMMA blend then decreased that was attributed to increase in miscibility of the blend involved. By UV-weathering, it was seen that thermal conductivity for PMMA increased with UV-weathering up to (30hr) then decreased, that was attributed to rigidity and defect formation, respectively. For 30%PS/PMMA, there results showed unsystematic decrease in thermal conductivity, which was attributed to unsystematic degradation. By Rain-weathering, thermal conductivity PS, PMMA, and 30 %PS, PMMA, it was seen systematic decreased in PS and 30 % PS/PMMA thermal conductivity; and systematic decrease in PMMA thermal conductivity. That due to the water diffusion in the samples that created some voids, bubbles, and results in decrease in thermal conductivity. This result was attributed to the decrease in adhesive between the components of polymer systems. The results suggested that the samples involved could be used for packaging application.

The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attributed to melting point of (PVA). Thermal properties of PVA; and St /PVA blends at different concentration (30, 40, 50, and 60 %) were evaluated by thermo gravimetric analysis (TGA). The analyses were carried out from 20 to 600 oC at 10 oC)/min heating rate in air oxygen atmosphere. The weight loss stages depended on polymer system. The starch addition causing shifting in the second degradation temperature to the higher temperature; which result in overlapping between the two main degradation steps, these result was attributed to the St/ PVA blend compatibility. The mechanical properties results showed a decrease in ultimate strength with starch ratio increase. The ultimate strength of (PVA) was (47 MPa), whereas the ultimate strength of 60 %St/PVA was (11 MPa) and for 30 %St/PVA was the highest ultimate strength of blends involved (26 MPa). SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at different concentrations (1.5, 2, and 2.5 %). 1.5% SiO2μPs, and NPs of the best ultimate strength (69 MPa), (86 MPa) respectively then it was decreased by SiO2μPs, and NPs increase. Optical microscope of the samples involved was investigated. It was concluded the prepared samples were suggested to be used as packaging materials for agriculture application and its ultimate strength could be controlled by SiO2μPs, and NPs addition.