{'fraction_non_alphanumeric': 0.014747191011235955, 'fraction_numerical': 0.007724719101123595, 'mean_word_length': 4.864197530864198, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
THE EFFECTS OF CHEMICAL AND ENVIRONMENTAL CONDITIONS ON THE DEGRADATION OF POLY LACTIC ACIDS

This paper describes a detailed study concerning the effects of chemicals like sodium hydroxide and environmental conditions such as temperature and time on the degradation of Poly lactic acid (PLA) as compared to Polyethylene terephthalate (PET). The aim is to study the effects of chemical and environmental conditions on the degradation of Poly lactic acids. In view of this, samples of PLA flat filament yarns and partially oriented PET yarns were hydrolysed with two different pH media i.e. neutral pH 7, and alkali pH 12.0-13.5 to study the physical changes that occurred in the yarn structure. Both the hydrolysed and non-hydrolysed yarns subjected to tensile test, DSC scans and FTIR analysis and the changes and the effects that took place before and after hydrolytic degradation at varied temperatures and times were analysed. The study showed that, at 60 o C and 90 o C hydrolysis yielded significant change in the physical appearance of the sample yarns as well as the structure. It could therefore be concluded that degradation highly occurred in the alkali medium than in the neutral medium when the time and temperatures were increased. This was also testified by the fact that elevated time and temperature aided in degrading the PLA flat filament yarns significantly than that of the partially oriented PET yarns.