Maleic anhydride based copolymer dispersions for surface modification of polar substrates

In this article, we report the modification of poly(styrene-alt-maleic anhydride) (PSMA) with monofunctional amine-terminated poly(dimethyl siloxane) (PDMS-NH2) by thermal imidization, followed by the preparation and characterization of a surfactant-free artificial latex thereof and application of this latex onto cotton fabric. The imidization reaction was monitored by NMR and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. 1,2-Cyclohexyldicarboxylic anhydride was chosen as a model compound for the PSMA copolymer; this allowed a more detailed characterization by NMR and ATR-FTIR spectroscopy. After the PSMA/PDMS-NH2 imidization reached completion, a fraction of the anhydrides were ammonolyzed. In this way, a self-emulsifying latex with an average particle diameter of approximately 145 nm and a ζ potential of -56 mV was obtained. It was found that the PDMS-modified PSMA latex in which 30 mol% of the initial amount of anhydride groups were previously imidized by using PDMS-NH2 and a fraction of the anhydrides were ammonolyzed with 0.3 eq. of NH3 (PSMA30) was stable in the pH range 4-10. The water contact angle values of the latex-coated cotton textile fabric indicated a hydrophobized surface, with a static contact angle of 135.7°Â± 1.2°. The washing studies with a standard soap solution of the cotton samples with or without crosslinker showed that the crosslinked PSMA30 offered a good coating durability to the cotton. This waterborne resin based on surfactant-free latices displayed promising properties for coating applications and seemed to be very suitable for the hydrophobization of polar surfaces. © 2012 Wiley Periodicals, Inc.