Abstract Polylactic acid fibrils (PLAf) were employed as a fiber component in papermaking. The addition of 5 wt % of PLAf to bleached kraft birch pulp increased the tensile index of the resulting 100 g/m2 paper sheets by 20 % in comparison to sheets produced without PLAf. By heat-treating the paper sheets containing 5 wt % PLAf, a 35 % higher tensile index in comparison to sheets produced without PLAf was achieved. SEM imaging showed that the heat-treatment caused the PLAf to melt, which formed a film on the fiber web. The PLAf was ultrasonicated in an attempt to make its surface more hydrophilic and anionic and thus more compatible with cellulose. Chemical additives (cationic polyacrylamide, polyethylene imine and polyethylene glycol) were added to the PLAf/cellulose pulp mixture in order to increase the binding between the ultrasonicated PLAf and cellulose. Ultrasonication caused the PLAf length to decrease and the PLAf surface charge changed by 36 %, indicating that the PLAf became significantly more anionic. Neither ultrasonication of PLAf nor the chemical additives improved the paper sheets’ stretchability. Polyethyleneimine as an additive in an amount of 1 % increased the tensile index of heat-treated sheets made with 5 wt % of PLAf by 19 %.

中文翻译：

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影响PLA原纤维与牛皮纸浆结合提高纸张干强度

摘要 聚乳酸原纤维 (PLAf) 被用作造纸中的纤维组分。与不使用 PLAf 生产的纸张相比，将 5 wt% 的 PLAf 添加到漂白牛皮纸桦木浆中后，所得 100 g/m2 纸张的拉伸指数增加了 20%。通过热处理含有 5 wt% PLAf 的纸张，与不含 PLAf 生产的纸张相比，实现了高 35% 的拉伸指数。SEM 成像显示热处理导致 PLAf 熔化，从而在纤维网上形成薄膜。PLAf 被超声处理以试图使其表面更具亲水性和阴离子性，从而与纤维素更相容。化学添加剂（阳离子聚丙烯酰胺、将聚乙烯亚胺和聚乙二醇）添加到 PLAf/纤维素纸浆混合物中，以增加超声处理的 PLAf 和纤维素之间的结合。超声处理导致 PLAf 长度减少，PLAf 表面电荷变化 36%，表明 PLAf 变得更加阴离子化。PLAf 的超声处理和化学添加剂均未改善纸张的拉伸性。聚乙烯亚胺作为添加剂以 1% 的量使由 5wt% PLAf 制成的热处理片材的拉伸指数增加 19%。