Cellulosic waste has stood out as potential materials for obtaining cellulose, since this raw material is highly available in a wide variety of species. These can be agricultural, forestry, or industrial. Cotton is an agricultural material of high cellulose content and great technological and economic importance. Another source with great potential is the waste from the paper industry. Both materials generate large amounts of waste that were little explored and uncorrected disposed. This work proposes the recycling of these two types of residue through the production of nanocellulose (cotton waste (CW-N) and industrial wastes (IW-N)) and their characterization by Fourier transform infrared spectroscopy, dynamic light scattering, X-ray photoelectron spectroscopy, X-ray diffraction, morphological analysis, and thermal properties. The nanocelluloses (NCs) were incorporated in poly(lactic acid) matrix, and the composites were evaluated mechanically. After the isolation of the nanocelluloses, it was found that both materials showed similar physicochemical characteristics, such as chemical functional groups and atomic composition. However, the morphologies are very distinct: the CW-N is nanofibrillar, with mean diameter around 30 nm, and the IW-N is spherical and irregular, with radius varying from 30 to 100 nm, which can be associated with the different crystalline structure of the materials. The differences in the structure were evaluated through Rietveld Refinement, and the industrial residue showed the presence of impurities in large amounts, and an increase in the cellulosic content after the conversion into nanoscale. The biocomposites showed a significant increase in the mechanical results, with improvement in the tensile strength from 63 to 69 and 78 MPa to agricultural and industrial nanocelluloses, respectively, which is associated with the good stress transfer between the fillers and the matrix and possible interactions between the active sites of PLA and nanocelluloses.

Graphic Abstract

中文翻译：

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来自工业和农业废料的纳米纤维素，可进一步用于PLA复合材料

纤维素废料已经成为获得纤维素的潜在材料，因为这种原料在各种各样的物种中都是高度可用的。这些可以是农业，林业或工业。棉花是纤维素含量高，技术和经济意义重大的农业材料。另一个具有巨大潜力的来源是造纸行业的废物。两种材料都会产生大量的废物，很少进行探索和纠正。这项工作提出了通过生产纳米纤维素（棉废料（CW-N）和工业废料（IW-N））回收这两种类型的残留物，并通过傅里叶变换红外光谱，动态光散射，X射线光电子进行表征。光谱学，X射线衍射，形态分析和热性质。将纳米纤维素（NCs）掺入聚乳酸基质中，并对复合材料进行机械评价。分离纳米纤维素后，发现两种材料都表现出相似的物理化学特征，例如化学官能团和原子组成。但是，形态非常不同：CW-N为纳米原纤维，平均直径约为30 nm，IW-N为球形且不规则，半径在30至100 nm之间变化，这可能与不同的晶体结构有关材料。通过Rietveld精制评估结构上的差异，并且工业残余物显示大量存在杂质，并且转化为纳米级后纤维素含量增加。

图形摘要