ABSTRACT
In view of environmental protection and sustainable use of resources, renewable biopolymers are highly sought as substitutes for traditional synthetic polymers from petroleum in applications as one-off materials. Starch is an economically important, highly functional, and renewable biopolymer present in a great variety of crops. Starch is also one of the most promising raw materials and commercially available ingredients for the production of biodegradable plastics [1]. Structurally, starch is a mixture of two main components: amylose, a linear or slightly branched (1-4)-α-dglucan, and amylopectin, a highly branched macromolecule consisting of (1-4)-α-glucan short chains linked through α-(1-6) linkages [2]. Typically, the degree of crystallinity of natural starch granules varies from about 15%–45% [3]. The crystallinity is usually characterized by wide-angle X-ray diffraction (WXRD) analysis. Granular starch crystallinity can be mainly classiŠed as A, B, and C types. The A type crystallinity is a closely packed arrangement with water molecules between each double helical structure, mainly found in cereal starches. The B type, usually sourced from tuber starches, is more open with more water molecules, essentially all of which are located in a central cavity surrounded by six double helices. The C pattern is a mixture of both A and B types, but also occurs naturally, for example, smooth-seeded pea starch and various bean starches. Three processing-induced single-helical amylose crystals, denoted as VA, VH, and EH, were reported in
CONTENTS
4.1 Introduction ............................................................................................................................69 4.2 Effect of Plasticizers on Properties of PS ............................................................................... 70 4.3 Effect of Water on Properties of PS ........................................................................................ 73 4.4 Effect of Starch Source on Properties of PS ........................................................................... 74 4.5 PS from ModiŠed Starch ........................................................................................................77
