Solid-phase extraction and gas chromatographic-mass spectrometric identification of degradation products from enhanced environmentally degradable polyethylene

A solid-phase extraction (SPE) method using unbonded silica (Si) and silica bonded with octadecyl (C₁₈) or aminopropyl (NH₂) groups was developed to separate into five fractions the highly complex mixture of low-molecular-mass degradation products formed from degradable polymers. Application of the method to polyethylene modified with starch and/or a pro-oxidant system, degraded for 30 weeks in water at 95°C, enabled the identification by GC-MS of over three times as many products as when the sample was prepared by liquid-liquid extraction. Over 60 degradation products were identified in each sample; mainly dicarboxylic acids, monocarboxylic acids and n-alkanes. In addition, several lactones, aldehydes and alcohols were detected.