Cabrera-Villamizar Laura, Núñez Eugenia, Reyes Alcira, Lizundia Erlantz, López-Rubio Amparo, Fabra María José
Food Safety and Preservation Department, Institute of Agrochemistry and Food Technology (IATA), CSIC, Carrer del Catedràtic Agustín Escardino Benlloch, 7, 46980, Valencia, Spain.
Food Safety and Preservation Department, Institute of Agrochemistry and Food Technology (IATA), CSIC, Carrer del Catedràtic Agustín Escardino Benlloch, 7, 46980, Valencia, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy - Spanish National Research Council (SusPlast), CSIC, Madrid 28006, Spain.
Int J Biol Macromol. 2025 Sep;322(Pt 2):146804. doi: 10.1016/j.ijbiomac.2025.146804. Epub 2025 Aug 12.
The environmental crisis caused by the accumulation of conventional plastics requires the development of sustainable alternatives. This study introduced a novel approach to valorize agricultural waste by engineering composite materials based on blends of poly(3-hydroxybutyrate-co-3-valerate) (PHBV) and polybutylene adipate terephthalate (PBAT) reinforced with rice straw (RS) as a possible alternative to conventional plastics. Composites were produced by melt compounding and compression molding, varying PHBV:PBAT mass ratios (80:20, 50:50, 20:80), RS particle sizes (≤250 μm and ≤ 500 μm), and RS concentration (20, 30 and 40 w/w %). Results showed that the polymer ratio and RS particle size significantly affected filler dispersion and film properties. Smaller RS particles and higher PHBV content (80:20) led to better homogenization, improved interfacial adhesion, and enhanced water vapor barrier properties, while 50:50 blends showed poor dispersion and higher permeability. Colorimetric analysis highlighted the role of RS size in composite coloration. FTIR confirmed that RS interacts physically with the polymers, not chemically. RS addition increased rigidity and water contact angle but reduced ductility, thermal stability, and crystallinity (depending on the concentration and particle size), and increased water vapor permeability. Disintegration tests revealed that only 80:20 blends met ISO 20200:2016 standards, while biodegradation, under industrial composting, was lower for RS-containing blends than controls, highlighting the role of environmental conditions and microbial communities. Life cycle assessment showed the composites had a cradle-to-grave climate change impact of 7.89-8.28 kg CO₂-eq·kg, which is lower than commercial plastics. These findings demonstrate the potential of rice straw as a sustainable filler for biodegradable PHBV/PBAT composites, offering promising alternatives for eco-friendly packaging applications.
传统塑料的堆积所引发的环境危机促使人们开发可持续的替代材料。本研究引入了一种新方法，通过以聚（3-羟基丁酸酯-co-3-戊酸酯）（PHBV）和聚己二酸对苯二甲酸丁二醇酯（PBAT）的共混物为基础，用稻草（RS）增强来制备复合材料，从而实现农业废弃物的增值利用，作为传统塑料的一种可能替代品。复合材料通过熔融共混和压缩成型制备，改变PHBV:PBAT质量比（80:20、50:50、20:80）、RS粒径（≤250μm和≤500μm）以及RS浓度（20、30和40 w/w%）。结果表明，聚合物比例和RS粒径显著影响填料分散和薄膜性能。较小的RS颗粒和较高的PHBV含量（80:20）导致更好的均匀化、改善的界面粘附以及增强的水蒸气阻隔性能，而50:50的共混物表现出较差的分散性和较高的渗透性。比色分析突出了RS尺寸在复合材料着色中的作用。傅里叶变换红外光谱（FTIR）证实RS与聚合物发生物理相互作用，而非化学相互作用。添加RS增加了刚性和水接触角，但降低了延展性、热稳定性和结晶度（取决于浓度和粒径），并增加了水蒸气渗透性。崩解试验表明，只有80:20的共混物符合ISO 20200:2016标准，而在工业堆肥条件下，含RS的共混物的生物降解率低于对照物，突出了环境条件和微生物群落的作用。生命周期评估表明，这些复合材料从摇篮到坟墓的气候变化影响为7.89 - 8.28 kg CO₂-eq·kg，低于商业塑料。这些发现证明了稻草作为可生物降解的PHBV/PBAT复合材料的可持续填料的潜力，为环保包装应用提供了有前景的替代方案。
