Development of biobased engineering materials

在过去的十年里，对生物塑料的兴趣和市场都有了戏剧性的增长。在这些生物塑料中，聚乳酸(或称聚乳酸)已成为最重要的年市场(约20亿美元)，年增长率接近20%。目前，聚乳酸的绝大多数应用都是短寿命的应用。然而，在更长期的工程应用中，由于聚乳酸的低温抗性和相对脆性，目前几乎没有人触及这些应用，这是一个完整的机会之窗。 这项拟议的研究旨在开发用于工程应用的新一代生物基塑料。该建议建立在目前对生物多聚酯结晶和结构-性质关系的理解基础上。这项研究将使开发具有更好韧性、抗冲击性和耐热性的生物基或部分生物基混合物成为可能，并将扩大新兴生物塑料的知识库。特别是，将探索聚酯/丙烯酸酯可混溶共混物的共混和结晶，以此作为提高耐热性的一种手段。将根据丙烯酸基聚合物中的共聚单体组成和生物聚酯的光学纯度来监测相分离。相分离将与所开发材料的热转变和整体性能相关联。在增韧方面，将探索功能化弹性体与生物聚酯的反应性共混，以开发具有成本竞争力的高冲击共混物。这项研究将研究可用的路线，如混合可与聚酯的酸性端基反应的环氧橡胶，以及混合含有可与聚酯相容的丙烯酸外壳的核壳弹性体。这些材料的一般工艺-结构-性能关系将被披露。 形成的高素质人员将获得聚合物加工方面的专业技能，通过电子显微镜、X射线衍射、原子力显微镜进行先进的材料表征，以及对聚合物产品制造的深入了解。目前人们对生物基聚合物有很大的兴趣，他们在研究生学习期间积累的专业知识将使HQP在他们未来的职业生涯中具有极大的吸引力。

In the past decade, the interest and market for bioplastics have grown dramatically. Among these bioplastics, polylactide (or PLA) has become the most important in terms of annual market (ca. $2 billion dollar) and boasts an annual growth rate close to 20%. The vast majority of applications for PLA are currently in short lifetime applications. There is a whole window of opportunity however in longer term engineering applications that are nearly untouched for the moment because of PLA’s low temperature resistance and relative brittleness. The proposed research aims at the development of a new generation of biobased plastics for engineering applications. The proposal builds on the current understanding of the crystallization and structure-property relationships of biopolyesters. The research will enable the development of biobased or partially biobased blends with improved toughness, impact resistance and thermal resistance and expand the knowledge base on emerging bioplastics. In particular, the blending and crystallization of polyester/acrylics miscible blends will be explored as a means to improve thermal resistance. The phase separation will be monitored as a function of the co-monomer composition in the acrylic based polymers and as a function of the optical purity of the biopolyester. The phase separation will be correlated with the thermal transitions and overall properties of the developed materials. On the toughening aspect, reactive blending of functionalized elastomers with biopolyesters will be explored in order to develop cost-competitive high impact blends. The research will investigate the available routes such as blending epoxydized rubbers that can react with acid end-groups of the polyester and blending of core-shell elastomers that contain an acrylic shell that is miscible with polyesters. The generic process-structure-property relationships of these materials will be disclosed. The formed highly qualified personnel will acquire specialized skills in polymer processing, advanced material characterization by electron microscopy, x-ray diffraction, atomic force microscopy as well as a deep understanding on the manufacturing of polymer products. There is currently a large interest for biobased polymers and the expertise developed during their graduate studies will make the HQPs highly attractive in their future professional career.