Effect of Cobalt Stearate and Vegetable Oil on Uv and Biodegradation of Linear Low-Density Poly(Ethylene)-Poly(Vinyl Alcohol) Blends

2011 ◽  
Vol 2 (4) ◽  
pp. 131-148 ◽  
Author(s):  
Francis Vidya ◽  
Subin S. Raghul ◽  
Sarita G Bhat ◽  
Eby Thomas Thachil
Keyword(s):  
Vegetable Oil ◽  
Vinyl Alcohol ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Low Density ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Degradation Behaviour ◽  
Moulding Process ◽  
Poly Ethylene

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found

scholarly journals Drug Amorphous Solid Dispersions Based on Poly(vinyl Alcohol): Evaluating the Effect of Poly(propylene Succinate) as Plasticizer

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2922
Author(s):  
Afroditi Kapourani ◽  
Artemis Palamidi ◽  
Konstantinos N. Kontogiannopoulos ◽  
Nikolaos D. Bikiaris ◽  
Panagiotis Barmpalexis
Keyword(s):  
Melting Temperature ◽  
Vinyl Alcohol ◽  
Solid Dispersions ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Melt Mixing ◽  
Amorphous Solid Dispersions ◽  
Quench Cooling ◽  
Poly Propylene

Although significant actions have been taken towards the utilization of poly(vinyl alcohol) (PVA) in the preparation of drug amorphous solid dispersions (ASDs) using fusion-based techniques (such as melt-quench cooling and hot-melt extrusion), several drawbacks regarding its rather high melting temperature and its thermal degradation profile make the use of the polymer extremely challenging. This is especially important when the active pharmaceutical ingredient (API) has a lower melting temperature (than PVA) or when it is thermally labile. In this vein, a previous study showed that newly synthesized polyester-based plasticizers may improve the processability and the thermal properties of PVA. However, the effects of such polyester-based plasticizers on the drug’s physicochemical and pharmaco-technical properties are yet unknown. Hence, the aim of the present study is to extend our previous findings and evaluate the use of poly(propylene succinate) (PPSu, i.e., the most promising plasticizer in regard to PVA) in the preparation of drug-loaded PVA-based ASDs. Dronedarone (DRN), a poorly water-soluble API, was selected as a model drug, and drug ASDs (using either neat PVA or PVA-PPSu) were prepared using the melt-mixing/quench cooling approach at low melting temperatures (i.e., 170 °C). DSC and pXRD analysis showed that a portion of the API remained crystalline in the ASDs prepared only with the use of neat PVA, while the samples having PPSu as a plasticizer were completely amorphous. Further evaluation with ATR-FTIR spectroscopy revealed the formation of significant intermolecular interactions between the API and the PVA-PPSu matrix, which could explain the system’s physical stability during storage. Finally, dissolution studies, conducted under nonsink conditions, revealed that the use of PVA-PPSu is able to maintain DRN’s sustained supersaturation for up to 8 h.

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

Miscible blends of poly(ethylene oxide) with brush copolymers of poly(vinyl alcohol)-graft -poly(l -lactide)

2016 ◽  
Vol 54 (13) ◽  
pp. 1217-1226 ◽  
Author(s):  
Ainhoa Lejardi ◽  
Jose-Ramon Sarasua ◽  
Agustin Etxeberria ◽  
Emilio Meaurio
Keyword(s):  
Ethylene Oxide ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Miscible Blends ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene
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