Virendrakumar Gupta

Alkoxy Silanes as External Donors for Polypropylene Procatalyst: Study on Polymerization Performance and Effect on Resin Properties

Effect of alkoxy silane [R1Si(OR2)3] on propylene polymerization was studied by systematic variation of functional groups e.g R2 = CH3, R1 = ‒OCH3, ‒CH3, ‒(CH2)2CH3, ‒(CH2)3N(CH3)2, ‒(CH2)3N(C2H5)2. Increase in bulkiness of alkyl group from ‒OCH3 to ‒(CH2)3N(C2H5)2 leads to decrease in productivity of catalyst with increase in MFI. Kinetics study revealed reduction of Rp0 and increase in decay kinetic constant with increase in bulkiness of functional groups. Morphology study by SEM of polypropylene particles illustrated that resin particle shape (particle circularity, topography and flowability) have been comparative. Polypropylene particle size distribution study revealed shift toward higher particles size regime for bulkier groups.

Broad Molecular Weight Polypropylene Synthesis using Mixed Internal Donor Incorporated Magnesium Dichloride Supported Titanium Catalyst

Magnesium dichloride supported titanium tetrachloride catalyst with mixed internal donor, comprised of ethylbenzoate and sulfolane, were synthesized. The composition characteristics of catalysts indicate incorporation of sulfolane to max 8.2 wt%, in addition to ethylbenzoate. The amount of incorporated donors in solid catalyst is dependent on the sulfolane concentration and reaction temperature of the process. A physical characteristics study of catalyst indicated that morphology, crystallite size, surface area, pore volume and titanium distribution have not been influenced much by incorporation of the second internal donor (sulfolane). The catalysts, in combination with triethyl aluminum as cocatalyst and p-ethoxyethylbenzoate as external donor, show good activity for propylene polymerization. The polypropylene synthesized with an optimized catalyst system shows broad molecular weight distribution as compared to ethylbenzoate based catalyst.

Recent Advances in Biodegradable Polymers

Biodegradable polymers are important as an alternative to conventional non-degradable polymers for sustainable eco-system. The recent trends indicate that the new developments in biodegradable polymers focus on novel polymer systems that can cater the need of biomedical and packaging applications in-terms of performance and economics. The new interest is rapidly moving toward reducing carbon footprint through utilization of carbon dioxide and developing new methods of manufacturing such as 3D printing for specific purposes. This review focus on the present state-of-art and recent developments in biodegradable polymers covering their sources, synthetic methodologies, salient properties, degradation patterns, polymer blends and nanocomposites. As well as biodegradable polymers as a 3D printing material and the use of carbon dioxide as a renewable raw material for biomedical and packaging applications.