Effects of starch alkenylsuccinylation on the grafting efficiency, paste viscosity, and film properties of alkenylsuccinylated starch-g-poly(acrylic acid)

Influence of Sulfododecenylsuccinylation on the Adhesion to Fibers and Film Properties of Corn Starch for Warp Sizing

To improve the film brittleness and adhesion to fibers of dodecenylsuccinated starch (DSS), DSS samples were sulfonated with excess NaHSO3 to prepare a series of sulfododecenylsuccinated starch (SDSS) samples with different degrees of substitution (DS). Their adhesion to fibers, surface tensions, film tensile properties and crystallinities, and moisture regains were studied. The results showed that the SDSS was superior to DSS and acid-thinned starch (ATS) in the adhesion to cotton and polyester fibers and breaking elongation of film but was inferior to them in tensile strength and degree of crystallinity of film, which revealed that sulfododecenylsuccination could further improve the adhesion of ATS to both fibers and reduce its film brittleness compared to starch dodecenylsuccination. With the increase in the DS, the adhesion to both fibers and the film elongation of SDSS gradually increased and then decreased, while its film strength consistently decreased. Considering adhesion and film properties, the SDSS samples with a DS range of 0.024-0.030 were recommended.

Effects of monomers and homopolymer contents on the dry and wet tensile properties of starch films grafted with various methacrylates

Starch grafted with four different methacrylates was compression molded to form thermoplastic films with good strength and water stability. Starch is an inexpensive and biodegradable polymer but is nonthermoplastic and needs to be chemically modified to make starch suitable for various applications. In this research, starch was grafted with four methacrylates (methyl, ethyl, butyl, and hexyl), and the effect of the length of the alkyl ester group on grafting parameters, thermoplasticity, and properties of thermoplastic films developed have been studied. Influence of grafting conditions on % grafting efficiency, % homopolymers, and % monomer conversion were studied, and the grafted starch was characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and nuclear magnetic resonance ((1)H NMR). At similar grafting ratios, butyl methacrylate (BMA) provided better strength and elongation to the starch films than the other three methacrylates. Grafting of methacrylates appears to be an economical approach to develop thermoplastic products from starch.