Pečnik Jaka Gašper, Zouari Mariem, Schwarzkopf Matthew, DeVallance David B
InnoRenew CoE, Livade 6a, 6310 Izola, Slovenia.
Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Titov Trg 4, 6000 Koper, Slovenia.
Polymers (Basel). 2023 Oct 5;15(19):3997. doi: 10.3390/polym15193997.
The torrefaction process is widely used in the energy field, but the characteristics of the torrefied wood also have positive effects on the production of wood plastic composites. In this study, short-rotation shrub willow was torrefied at 225 and 300 °C and incorporated into polypropylene composites filled with changing levels of weight percent (wt%) of non-torrefied and torrefied (5, 15, 25, and 40 wt%) wood. Nine different formulations were extruded for mechanical, thermal, and water absorption properties. The tensile properties of composites were not affected by any level of torrefaction, while higher flexure properties were in favor of lower wt% of torrefied wood. The slowest rate of thermal degradation was confirmed for the highest wt% of torrefied wood with a torrefaction temperature of 300 °C. In contrast, the presence of torrefied wood in composites did not show a difference in crystallization or melting temperatures. The most noticeable contribution of torrefaction temperature and wt% was found for water-absorbing properties, where the higher torrefaction temperature and largest wt% of torrefied wood in the composite resulted in decreased water uptake.
烘焙过程在能源领域被广泛应用，但烘焙木材的特性对木塑复合材料的生产也有积极影响。在本研究中，短轮伐期灌木柳在225℃和300℃下进行烘焙，并被加入到填充有不同重量百分比（wt%）的未烘焙和烘焙木材（5、15、25和40 wt%）的聚丙烯复合材料中。共挤出了九种不同配方的材料以测试其机械、热学和吸水性能。复合材料的拉伸性能不受任何烘焙程度的影响，而较高的弯曲性能则有利于较低wt%的烘焙木材。对于烘焙温度为300℃且wt%最高的烘焙木材，其热降解速率最慢。相比之下，复合材料中烘焙木材的存在并未使结晶温度或熔融温度出现差异。烘焙温度和wt%对吸水性能的影响最为显著，其中较高的烘焙温度和复合材料中最大wt%的烘焙木材导致吸水率降低。
