Guidotti Giulia, Burzotta Gianfranco, Soccio Michelina, Gazzano Massimo, Siracusa Valentina, Munari Andrea, Lotti Nadia
Civil, Chemical, Environmental and Materials Engineering Department, University of Bologna, Via Terracini 28, 40131 Bologna, Italy.
Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials Technology, CIRI-MAM, University of Bologna, 40126 Bologna, Italy.
Polymers (Basel). 2021 Aug 13;13(16):2707. doi: 10.3390/polym13162707.
Among the several actions contributing to the development of a sustainable society, there is the eco-design of new plastic materials with zero environmental impact but that are possibly characterized by properties comparable to those of the traditional fossil-based plastics. This action is particularly urgent for food packaging sector, which involves large volumes of plastic products that quickly become waste. This work aims to contribute to the achievement of this important goal, proposing new bio-based cycloaliphatic polymers based on -1,4-cyclohexanedicarboxylic acid and containing different amount of camphoric acid (from 0 to 15 mol %), a cheap and bio-based building block. Such chemical modification was conducted in the melt by avoiding the use of solvents. The so-obtained polymers were processed in the form of films by compression molding. Afterwards, the new and successfully synthesized random copolymers were characterized by molecular (NMR spectroscopy and GPC analysis), thermal (DSC and TGA analyses), diffractometric (wide angle X-ray scattering), mechanical (through tensile tests), and O and CO barrier point of view together with the parent homopolymer. The article aims to relate the results obtained with the amount of camphoric moiety introduced and to present, the different microstructure in the copolymers in more detail; indeed, in these samples, a different crystalline form developed (the so-called β-PBCE). This latter form was the kinetically favored and less packed one, as proven by the lower equilibrium melting temperature determined for the first time by Baur's equation.
在有助于可持续社会发展的诸多行动中，有一种是对新型塑料材料进行生态设计，使其对环境零影响，但可能具有与传统化石基塑料相当的性能。这一行动对食品包装行业尤为紧迫，因为该行业涉及大量塑料制品，这些制品很快就会成为废弃物。这项工作旨在为实现这一重要目标做出贡献，提出基于 -1,4-环己烷二甲酸并含有不同量（0至15摩尔%）樟脑酸的新型生物基脂环族聚合物，樟脑酸是一种廉价的生物基结构单元。这种化学改性是在熔融状态下进行的，避免使用溶剂。如此得到的聚合物通过压缩模塑加工成薄膜形式。之后，从分子层面（核磁共振光谱和凝胶渗透色谱分析）、热性能层面（差示扫描量热法和热重分析）、衍射层面（广角X射线散射）、机械性能层面（通过拉伸试验）以及氧气和二氧化碳阻隔性能层面，对新合成的成功的无规共聚物以及母体均聚物进行了表征。本文旨在将所得结果与引入的樟脑酸部分的量相关联，并更详细地呈现共聚物中不同的微观结构；实际上，在这些样品中形成了一种不同的晶型（所谓的β-PBCE）。正如首次由鲍尔方程确定的较低平衡熔点所证明的那样，后一种晶型是动力学上更有利且堆积较少的晶型。
