Chitin is widespread in nature and is increasingly used in synthetic process for the production of new biomaterials. Chitin degree of acetylation, crystalline structure and microfibril arrangement differentiate chemical, physical and mechanical properties. Nevertheless, no information are available on the relationship between the mechanical properties and the degree of acetylation (DA) in chitin samples in which the microfibril arrangement does not change. Here, samples of β-chitin with decreasing DA, up to chitosan, were prepared using the squid pen of Loligo vulgaris. These samples were characterized by CP-MAS NMR spectroscopy, scanning electron microscopy, thermal analyses, synchrotron X-ray fiber diffraction and tensile tests. The results showed a similar microfibril arrangement decreasing the DA, except for the chitosan sample. The mechanical properties showed an increase of the maximum strain and a reduction of the maximum stress and Young’s modulus, decreasing the DA. These changes, not linear with the DA, were related to structural changes at molecular structure level. The knowledge deriving from this study is of interest both for the understanding of the mechanical properties of chitinous biological samples, but also for the design and synthesis of new biomacromolecular materials.

几丁质在自然界中广泛存在，并越来越多地用于合成过程中以生产新的生物材料。甲壳素的乙酰化程度，晶体结构和微纤维排列可区分化学，物理和机械性能。然而，在微纤丝排列不变的几丁质样品中，机械性能与乙酰化程度（DA）之间的关系尚无可用信息。在这里，使用寻常的Loligo鱿鱼笔制备DA降低至壳聚糖的β-甲壳质样品。这些样品通过CP-MAS NMR光谱，扫描电子显微镜，热分析，同步加速器X射线纤维衍射和拉伸测试进行了表征。结果表明，除了壳聚糖样品外，相似的微纤维排列降低了DA。力学性能显示最大应变增加，最大应力和杨氏模量减少，从而降低了DA。这些变化与DA呈线性关系，与分子结构水平的结构变化有关。从这项研究中获得的知识不仅对于了解几丁质生物样品的机械性能，而且对于新型生物大分子材料的设计和合成都具有重要意义。