The Degradation Behavior of TPS/LDPE Blend Mulch Films Prepared with Different Pro-oxidants

Abstract

Low density polyethylene LDPE was blended with thermoplastic starch TPS by twin screw compounder to prepare partially degradable mulch films. In the present study, ferric stearate and manganese II stearate were used as pro-oxidant and the effect of different pro-oxidants on the degradation of the blends were investigated. The blended mulch films were buried in soil inoculated with Coriolus versicolor L. Quél. for 180 days for the degradation. The chemical structures of the films were evaluated by FTIR spectroscopy and the weight loss of all samples was measured before and after soil burial treatment. The effects of two different pro-oxidants on thermal and tensile properties of blends were determined by TGA and mechanical analysis. A synergetic effect between ferric stearate and citric acid was observed. Using both in the blends resulted in higher thermal stability of TPS in the blends. Significant improvement of the mechanical properties was also observed. However, when manganese II stearate used together with citric acid a decrease in the mechanical properties was observed compared blends with stearic acid.

Keywords

• LDPE,thermoplastic starch,pro-oxidant,ferric stearate,manganese II stearate

Farklı Pro-oksidanlar ile Üretilmiş TPN/AYPE Karışım Malç Filmlerin Bozunma Davranışı

Abstract

K ısmen bozunabilen malç filmleri hazırlamak için az yoğunluklu polietilen AYPE , termoplastik nişasta TPN ile çift vidalı ekstruder yardımıyla karıştırıldı. Bu çalışmada, demir III stearat ve manganez II stearat pro-oksidan olarak kullanılmışve farklı pro-oksidanların karışımların bozunması üzerindeki etkisi incelenmiştir. Malç filmler Coriolus versicolor L. Quel ile aşılanmış toprağa gömülerek 180 gün boyunca degrede edilmiştir. Filmlerin kimyasal yapıları FTIR spektroskopisi ile belirlenmiş ve tüm numunelerin ağırlık kaybı toprakta bozunma öncesi ve sonrası ölçülmüştür. İki farklı pro-oksidanın, malç karışımların ısıl ve germe özellikleri üzerine etkisi TGA ve mekanik analiz ile tespit edilmiştir. Demir III stearat ve sitrik asitin birlikte kullanılmasıyla sinerjik bir etki gözlenmiştir. Her ikisinin birlikte kullanıldığı karışımlarda TPN’nin yüksek ısıl kararlılık gösterdiği bulunmuştur. Ayrıca, mekanik özelliklerinde belirgin düzelme gözlenmiştir. Bununla birlikte, manganez II stearat sitrik asit ile birlikte kullanıldığında stearik asitli karışımlarına kıyasla daha zayıf mekanik özellikler göstermiştir

Keywords

• AYPE,termoplastik nişasta,pro-oksidan,demir stearat,manganez II stearat

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