Ghosh Rinky, Zhao Xiaoying, Vodovotz Yael
Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210, USA.
School of Light Industry Science and Engineering, Beijing Technology and Business University, No. 33 Fucheng Road, Beijing 100048, China.
Polymers (Basel). 2025 May 13;17(10):1324. doi: 10.3390/polym17101324.
The inherent brittleness of bio-based poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) significantly restricts its industrial applications despite its industrial compostability. Blending with elastomeric polymers addresses mechanical limitations; however, interfacial incompatibility compromises miscibility as our previous work established. Herein, we investigate coffee oil epoxide (COE) as a bio-based plasticizer for PHBV/natural rubber (NR) blends in sustainable packaging applications. COE, derived from spent coffee grounds, was incorporated into PHBV/NR/peroxide/coagent composites via twin-screw extrusion. FTIR spectroscopy with chemometric analysis confirmed successful COE incorporation (intensified CH stretching: 2847, 2920 cm; reduced crystallinity), with PCA and PLS-DA accounting for 67.9% and 54.4% of spectral variance. COE incorporation improved optical properties (7.73% increased lightness; 21.9% reduced yellowness). Rheological characterization through Cole-Cole and Han plots demonstrated enhanced phase compatibility in the PHBV/NR/COE blends. Mechanical testing showed characteristic reductions in flexural properties: strength decreased by 16.5% and modulus by 36.8%. Dynamic mechanical analysis revealed PHBV/NR/COE blends exhibited a single relaxation transition at 32 °C versus distinct glass transition temperatures in PHBV/NR blends. Tan δ deconvolution confirmed the transformation from bimodal distribution to a single broadened peak, indicating enhanced interfacial interactions and improved miscibility. These findings demonstrated COE's potential as a sustainable additive for biodegradable PHBV-based packaging while valorizing food waste.
尽管生物基聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（PHBV）具有工业可堆肥性，但其固有的脆性严重限制了其工业应用。与弹性体聚合物共混可解决机械性能方面的限制；然而，正如我们之前的工作所证实的，界面不相容性会影响共混物的混溶性。在此，我们研究了咖啡油环氧化合物（COE）作为一种生物基增塑剂，用于可持续包装应用中的PHBV/天然橡胶（NR）共混物。源自废弃咖啡渣的COE通过双螺杆挤出工艺被引入到PHBV/NR/过氧化物/助交联剂复合材料中。采用化学计量学分析的傅里叶变换红外光谱（FTIR）证实了COE的成功引入（增强的CH伸缩振动：2847、2920 cm；结晶度降低），主成分分析（PCA）和偏最小二乘判别分析（PLS-DA）分别解释了67.9%和54.4%的光谱方差。COE的引入改善了光学性能（亮度增加7.73%；黄度降低21.9%）。通过Cole-Cole图和Han图进行的流变学表征表明，PHBV/NR/COE共混物的相相容性得到了增强。力学测试显示弯曲性能有典型下降：强度下降了16.5%，模量下降了36.8%。动态力学分析表明，PHBV/NR/COE共混物在32℃出现单一的松弛转变，而PHBV/NR共混物有明显不同的玻璃化转变温度。损耗角正切（Tan δ）去卷积证实了从双峰分布转变为单一的宽峰，表明界面相互作用增强且混溶性提高。这些发现证明了COE作为一种可持续添加剂用于基于可生物降解PHBV的包装的潜力，同时还能使食品废料增值。
