Thermal characterisation of photo-oxidized HDPE/Mater-Bi and LDPE/Mater-Bi blends buried in soil

• Published in: Journal of applied polymer science 2008-07, Vol.109 (2), p.1177-1188
• Main Authors: Moriana-Torró, R, Contat-Rodrigo, L, Santonja-Blasco, L, Ribes-Greus, A
• Format: Article
• Language: English
• Subjects: Ageing; Applied sciences; Biochemistry; biodegradability; Biodegradable materials; Biodegradation; Biodegradation processes; Bismuth plating; Calorimetric analysis; Calorimetry; Characterisation; Chemical oxygen demand; Coats-redfern; Decomposition; Decomposition mechanisms; Degradation; Differential scanning calorimetry; Exact sciences and technology; Irradiation; Kinetic modelling; Laser interferometry; Low density; Master curves; Mater Bi; Matrix algebra; Microbiology; Morphological changes; optical property; Oxidation; Photo oxidations; Photo-oxidation; Photoresists; Physical properties; Polyethylene; Polyethylene matrix; polymer blend; Polymer industry, paints, wood; Polymeric matrices; Properties and testing; Pyrolysis; Scanning calorimetry; soil burial test; Soil burial tests; Soil processing; Soils; Sulfate minerals; Synergetic effects; Technology of polymers; Testing; thermal property; Thermogravimetric analysis; Thermoplastics; UV irradiations
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.28171

Blends of high and low density polyethylene with a commercial biodegradable material (Mater-Bi) were subjected to an accelerated soil burial test. A set of samples was previously photo-oxidized to evaluate the effects of UV-irradiation on the degradation in soil process of these blends. Thermogravimetric as well as calorimetric analysis were performed to study the biodegradation, photo-degradation and their synergetic effects. Differential scanning calorimetry was carried out to analyze the morphological changes as a consequence of the photo-oxidation process. UV-irradiation slightly modifies the crystalline content of HDPE/Mater-Bi blends, increasing the heterogeneity of this blend. Criado master curves were plotted to analyses the degradation kinetic model. Broido and Coats-Redfern methods have been used for calculating the Ea of the thermal decomposition mechanisms. Thermogravimetric results reveal that noncomplexed starch is more affected by biodegradation than the polyethylene matrix and the starch/EVOH complexes chains from Mater-Bi. However, the effects of both photo-oxidation and biodegradation processes on the thermal decomposition of Mater-Bi is influenced by the polymeric matrix used. Previous photo-oxidation finds to slow down the degradative effects caused by the soil burial test on the HDPE/Mater-Bi blends.