Aiming at better understanding the ageing behaviour of cellulose composites, the accelerated thermo-oxidative ageing of polyethylene reinforced with two types of wood-based cellulose fibres was studied. Materials were prepared by extrusion mixing of either un-stabilized or stabilized polyethylene reinforced with 5 and 20 vol % cellulose content. The materials were extruded into strips and then aged at 90°C in circulating air. The effect of accelerated ageing up to 31 days was assessed by oxidation induction time and mechanical properties in tension. The results indicated that the added cellulose fibres did not increase the degradation of the composites during this ageing. Reinforcement with 20 % cellulose fibre having a 28 % lignin content together with 0.005 % Irganox 1010 antioxidant resulted in a remarkable improvement in the resistance against accelerated thermo-oxidation, compared to the pure polyethylene with added antioxidant. The findings of increased lifetime of LDPE by addition of wood-based reinforcement is of great interest, since the durability aspect is crucial to understand and predict before usage in commercial applications and especially as structural composites.

为了更好地理解纤维素复合材料的老化行为，研究了两种木基纤维素纤维增强的聚乙烯的加速热氧化老化。通过挤压混合纤维素含量为5和20 vol％的未稳定或稳定的聚乙烯来制备材料。将材料挤出成条，然后在循环空气中于90°C时效。通过氧化诱导时间和拉伸机械性能评估了加速老化直至31天的影响。结果表明，在老化过程中，添加的纤维素纤维不会增加复合材料的降解。用具有28％木质素含量和0的20％纤维素纤维进行增强。与添加了抗氧化剂的纯聚乙烯相比，005％Irganox 1010抗氧化剂显着提高了抗加速热氧化性。通过添加木基增强剂来提高LDPE使用寿命的发现引起了极大的兴趣，因为耐久性方面对于在商业应用中尤其是作为结构复合材料使用之前的理解和预测至关重要。