Preparation and Performance Study of the Full-degradable Polythene Films
|School||Shandong University of Science and Technology|
|Keywords||Polythene film Degradable Montmorillonite (MMT) Ferric stearate （FeSt3） Iron montmorillonite (Fe-OMMT)|
The background of this subject was existence severe "white pollution" problem leaded by the hard collected and degraded plastics. The organically modified of montmorillonite (MMT) and the preparation of iron montmorillonite (Fe-OMMT) by in-situ hydrothermal synthesis were mainly studied in this subject. The blow molding process of the full-degradable polythene film was researched in this subject. After the ultraviolet accelerated photo-degradation and the naturally buried degradation, the changing about carbonyl index (CI) and molecular weight of the full-degradable polythene film were studied in this subject. The relationship between carbonyl index, molecular weight and the kinds, the contents of additives was proposed in this paper.This study showed that the organic iron montmorillonite prepared by one step hydrothermal synthesis was effective in increasing the MMT layer spacing. It could strip in linear low density polythene (LLDPE) and could lead Fe ion to disperse evenly on montmorillonite slice layer.After ultraviolet accelerated aging test, the two LLDPE films contained the ferric stearate (FeSt3) and Fe-OMMT was degraded; carbonyl index increased and molecular weight decreased. This result showed that FeSt3 and Fe-OMMT were excellent photosensitizers which could photo-initiate the photo catalytic-oxidation reaction of LLDPE film and cause LLDPE chain interruption. Through the analysis of the relationship between carbonyl index, molecular weight and the kinds of additives in ultraviolet aging test, it could be showed that FeSt3 and Fe-OMMT had similar photosensitive degradation activity and were excellent photosensitizers.After 120 days naturally buried, the LLDPE film contained 1.0% Fe-OMMT entered into decay stage, its carbonyl index increased to 20 and molecular weight decreased sharply, its degradation process was obvious. The LLDPE film contained 0.6% FeSt3 entered into decomposition stage, its carbonyl index increased to 15 and it began to be degraded. Through the analysis of the relationship between carbonyl index, molecular weight and the kinds of additives in naturally buried test, it was showed that the degradation activity of Fe-OMMT was much better than FeSt3. In the burying and no illumination conditions, Fe-OMMT still initiated LLDPE film degradation.