Martins Julia Ribeiro, Llanos Jaiber Humberto Rodriguez, Abe Mateus Manabu, Costa Michelle Leali, Brienzo Michel
Institute for Research in Bioenergy (IPBEN), São Paulo State University (Unesp), 13500-230, Rio Claro, SP, Brazil.
Materials and Technology Department, School of Engineering, São Paulo State University (Unesp), Av. Dr. Ariberto Pereira da Cunha 333, Guaratinguetá, 12516-410, Brazil; Lightweight Structures Laboratory (LEL/IPT), Rod. Presidente Dutra, s/n, 137, 8 km - Eugenio de Melo, São José dos Campos, 12247-004, Brazil.
Carbohydr Res. 2024 Mar;537:109068. doi: 10.1016/j.carres.2024.109068. Epub 2024 Feb 22.
Renewable materials of biological origin exhibit attractive properties in relation to traditional plastics, as they can be partially or completely replaced, thereby reducing environmental impacts. Hemicelluloses are a group of polysaccharides that have expanded applications when acetylated. Acetylation can improve the mechanical strength and water vapor barrier properties of xylan-based bioplastics. By partially acetylating xylan in the present study, it was possible to use water as a solvent for the film-forming solution and starch as a second polysaccharide in the formation of bioplastics. Xylan was modified via partial chemical acetylation by varying the reaction time, solvent, and catalyst content. The bioplastics were formed by non-acetylated xylan and acetylated xylan with degrees of substitution (DS) of 0.45 and 0.9, respectively, with starch to form blends using glycerol as a plasticizer. Acetylation with DS 0.45 showed better results in increasing the hydrophilicity of the bioplastic. On the other hand, acetylation influenced the thermal stability of bioplastics, increasing the maximum temperature of the degradation rate from 302 °C to 329 °C and 315 °C, owing to changes in the crystallinity of the polymers. In addition to the modulus of elasticity 2.99 to 290.61 and 274.67 MPa for the non-acetylated bioplastic and the bioplastic with DS of 0.45 and 0.90, respectively. Thus, the films obtained presented suitable physicochemical properties for use in various industrial applications, such as active and intelligent packaging in the food sector.
与传统塑料相比，生物源可再生材料具有吸引人的特性，因为它们可以被部分或完全替代，从而减少对环境的影响。半纤维素是一类多糖，乙酰化后具有更广泛的应用。乙酰化可以提高基于木聚糖的生物塑料的机械强度和水蒸气阻隔性能。在本研究中，通过对木聚糖进行部分乙酰化，可以使用水作为成膜溶液的溶剂，并在生物塑料的形成过程中使用淀粉作为第二种多糖。通过改变反应时间、溶剂和催化剂含量，对木聚糖进行部分化学乙酰化改性。生物塑料由未乙酰化的木聚糖和取代度（DS）分别为0.45和0.9的乙酰化木聚糖与淀粉混合而成，使用甘油作为增塑剂。取代度为0.45的乙酰化在提高生物塑料亲水性方面显示出更好的效果。另一方面，乙酰化影响了生物塑料的热稳定性，由于聚合物结晶度的变化，降解速率的最高温度从302℃提高到329℃和315℃。此外，未乙酰化生物塑料以及取代度为0.45和0.90的生物塑料的弹性模量分别为2.99至290.61和274.67MPa。因此，所获得的薄膜具有适用于各种工业应用的理化性质，例如食品领域的活性和智能包装。
