In this research, we studied cross-linking of cotton fabrics using the combination of itaconic acid (ITA) and sodium hypophosphite (NaH 2 PO 2 ). ITA, a bifunctional carboxylic acid, was able to esterify cotton cellulose to form a single ester linkage, but it was not able to form cross-linking between two cellulose molecules. In the presence of NaH 2 PO 2 , the amount of ester formed on cotton fabric was increased substantially and the esterification temperature of ITA was reduced. Therefore, NaH 2 PO 2 functioned as a catalyst for esterification of cotton by ITA. Moreover, we found that wrinkle resistance of the cotton fabric was significantly improved when cotton fabrics were treated with the combination of ITA and NaH 2 PO 2 .We also found that phosphorus was bound to the treated cotton fabric and that the increase in the wrinkle recovery angle of the treated fabric was correlated to the increase in the amount of phosphorus bound to cotton. All the data indicated that H−P−H of sodium hypophosphite probably reacts with the >CC< of two ITA molecules, which are also esterified with cellulose, thus forming a cross-linkage between the two cellulose molecules. The cotton fabrics treated with the ITA/NaH 2 PO 2 system demonstrated a high level of durable press performance with significantly lower tensile strength loss than those treated with the formaldehydebased dimethyloldihydroxyethyleneurea.

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In response to the defects of easy delamination, poor impact resistance, and low toughness in laminates, intra-layer aramid/glass hybrid weft-knitted reinforced composites without lamination were designed and prepared. This paper investigated the tensile, bending, and impact response of aramid/glass hybrid weft-knitted reinforced composites. Homogeneous and hybrid composites with glass: aramid hybrid ratios of 1:1, 2:1, 3:1, and hybrid modes of transverse hybrid, oblique hybrid, and vertical interlocking hybrid were prepared by vacuum resin transfer molding (VARTM) technique. The tensile and bending properties were evaluated from stress, modulus, and strain/deflection, and a scanning electron microscope (SEM) was employed. The impact response was analyzed from peak force, maximum displacement, and energy absorption. The results confirm that interlacing brittle glass yarns with aramid yarns exhibits a positive hybrid effect. The ratios of 50%, 33%, and 25% aramid fiber in the transverse hybrid enhanced the longitudinal strength by 72.86%, 52.13%, and 22.01%. The mechanical properties of the oblique hybrid are similar in warp and weft direction; by contrast, the other two hybrid methods demonstrate mechanical anisotropy. This article implements the preparation and mechanical properties research of non-laminated hybrid composites based on weft-knitted structures, which broadens the design and selection of prefabricated components for hybrid composites.