Amine activators influence on grafting reaction between methacrylic acid and starch

How starch-g-poly(acrylamide) molecular structure effect sizing properties

The effect of starch-g-poly(acrylamide) (S-g-PAM) molecular structure on sizing properties has been investigated. S-g-PAMs were synthesized with the catalysis of horseradish peroxidase (HRP) and Fourier transform infrared (FT-IR) confirmed the acrylamide (AM) units had been successfully grafted on starch chains. Structural parameters, including degree of branching (DB), degree of substitution (DS) and grafting ratio (GR) were characterized by ¹H nuclear magnetic resonance (¹H NMR), and were correlated with sizing properties of apparent viscosity, adhesion to cotton yarns and film mechanical properties. The apparent viscosity of S-g-PAMs has no obvious correlation with DB and DS (or GR), as the amylose content of the native starch might have more influence on the viscosity of grafted starches. DS (or GR) values of grafted starches have a positive relationship with the tensile strength of sized cotton yarns and are negatively related with tensile strength of starch film. These results can provide guidance in the section of starch with improved sizing properties.

Characterization and properties of biodegradable thermoplastic grafted starch films by different contents of methacrylic acid

Due to poor mechanical and thermal properties of native starch (NS) film; in the present work; NS was modified by graft copolymerization. Thermoplastic starch (TPS) grafted by methacrylic acid (MAA) with different percentage of grafting, i.e., 0%, 18.3%, 36.3%, 52.1% and 89.7% were prepared and tested. The result demonstrated that the intensity of IR peak of acrylic group increased with the increasing percentage of grafting. The higher graft copolymerization with MAA also significantly reduced degree of crystallinity. The strain at maximum load of TPS film grafted by MAA increased with the increasing percentage of grafting. However, water uptake of TPS film grafted by MAA reduced with high percentage of grafting (52.1% and 89.7%). In addition, different TPS films grafted by MAA were also examined for morphology, water vapor permeability, thermal property and biodegradable property by soil buried test.

Introduction of poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid)] branches onto starch for cotton warp sizing

An attempt has been made to reveal the effect of amphoteric poly(2-acryloyloxyethyl trimethyl ammonium chloride-co-acrylic acid) [P(ATAC-co-AA)] branches grafted onto the backbones of starch upon the adhesion-to-cotton, film properties, and desizability of maize starch for cotton warp sizing. Starch-g-poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid) [S-g-P(ATAC-co-AA)] was prepared by the graft copolymerization of 2-acryloyloxyethyl trimethyl ammonium chloride (ATAC) and acrylic acid (AA) with acid-converted starch (ACS) in aqueous medium using Fe(2+)-H2O2 initiator. The adhesion was evaluated in term of bonding strength according to the FZ/T 15001-2008 whereas the film properties considered included tensile strength, work and percentage elongation at break. The evaluation was undertaken through the comparison of S-g-P(ATAC-co-AA) with ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride). It was found that the amphoteric branch was able to significantly improve the adhesion and mitigate the brittleness of starch film. Zeta potential of cooked S-g-P(ATAC-co-AA) paste, depending on the mole ratio of ATAC to AA units on P(ATAC-co-AA) branches, had substantial effect on the adhesion and desizability. Increasing the mole ratio raised the potential, which favored the adhesion but disfavored the removal of S-g-P(ATAC-co-AA) from sized cotton warps. Electroneutral S-g-P(ATAC-co-AA) was superior to negatively grafted starch in adhesion and to positively grafted starch in desizability. Generally, it showed better sizing property than ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride), and had potential in the application of cotton warp sizing.

Grafting poly(2-acryloyloxyethyl trimethyl ammonium chloride) branches onto the backbones of corn starch for toughening starch film

This work was undertaken to examine the effect of poly(2-acryloyloxyethyl trimethyl ammonium chloride) (PATAC) branches grafted onto the backbones of starch on the toughening of starch film. A series of starch-g-PATAC samples having different levels of grafting ratio were prepared by the graft copolymerization of granular corn starch with ATAC in an aqueous system, using Fenton’s initiator through changing the weight ratio of the monomer to starch. The influences of grafted branches on the properties such as tensile strength, breaking elongation, work-to-break, bending endurance, moisture regain, swelling power, and solubility of starch film were evaluated by comparison with those of acid-treated starch (ATS). It was found that the branches were able to toughen starch film due to the significant increases in breaking elongation, work-to-break and bending endurance of the film. The branches were also able to increase its moisture regain, water swelling power, and solubility. In addition, the properties were dependent on the amount of the branches. Furthermore, the grafted starch was biodegradable when its grafting ratio did not exceed 7.5 wt%.