A Methacrylic Anhydride Difunctional Precursor to Produce a Hydrolysis-Sensitive Coating by Aerosol-Assisted Atmospheric Plasma Process

Abstract

In this paper, we focused our attention on the elaboration of a hydrolyzable plasma‐polymer produced by aerosol‐assisted atmospheric pressure plasma process. A dielectric barrier discharge (DBD) was hence fed with a commercial methacrylic anhydride precursor – bearing an anhydride hydrolyzable function and two methacrylates groups aiming at producing a highly cross‐linked deposit – to produce thin coatings of plasma‐polymerized (pp) methacrylic anhydride. IR and NMR were performed to highlight the retention of the hydrolyzable group. After immersion in water, mass spectrometry analysis was conducted on the aqueous medium to characterize the end‐products and consequently confirm the occurrence of a hydrolytic degradation. A huge 80% thickness decrease was finally pointed out by nanoscratch measurements after 10 days.

Challenges in the characterization of plasma polymers using XPS

“…[17,142]. These vibrations even enable discrimination, for instance, between the allyl and the vinyl groups [17].…”

“… Enables unambiguous identification of carbons in specific polyesters such as poly(propylene-maleic anhydride) copolymers [146] or pp-methacrylic anhydride [142].…”

“…Combined to principal component analysis (PCA), ToF-SIMS enables to evaluate the degree of crosslinking of ppethyl lactate[149]  Mertz et al used "cross polarization" 13 C NMR to enhance detection of carbon atoms from more crosslinked and rigid backbones in pp-methacrylic anhydride[142].…”

In Situ Generation of Plasma-Polymer Standards by Plasma Assisted Free Radical Polymerization

“…Thin films deposited from plasma-polymerization exhibit different structures than those obtained from conventional polymerization methods, hence offering other and specific properties. [1][2][3] In particular, atmospheric plasma processes and more precisely aerosol assisted plasma polymerization routes (AAPP) [4] are gaining more and more interest within the surface science community owing to the possibility they offer to plasma-polymerize non volatile precursors [5] or directly inject nanoparticles to produce thin hybrid nanocomposites. [6,7] Regardless of these indubitable advan-tages, being a polymerization technique of its own with a rather limited knowledge about the reaction routes, a meaningful analysis of (aerosol assisted) plasma polymers hence requires characterization techniques or strategies to be specifically implemented.…”

“…Standards could be of various sources, either commercial if the polymers of interest are widely used or easy to produce, or from home-made synthesis if precursors are a bit more exotic, using more or less controlled reactions. The specific case of acrylate precursors is of high interest -and will constitute the topic of the present paper -because of (a) their high reactivity towards the plasma discharge which allows both heavily cross-linked structures to be deposited [21] and fragile functional groups to be preserved thanks to a reduced plasma power, [5] hence raising a growing interest into the plasma community [22][23][24] and (b) such class of compounds readily polymerize in ''wet'' conditions using radical polymerization (either free or controlled, as discussed later). Reference products are then directly synthesized from the precursor used in the plasma polymerization and expected to mimic the associated plasma-polymers.…”