Effect of the length of branches on the critical surface tension of poly(n-alkyl methacrylates) and copolymers of stearyl methacrylate with methacrylonitrile

Abstract

synopsisCritical surface tension values yc were measured for poly(n-alkyl methacrylates) and copolymers of stearyl methacrylate with methacrylonitrile. Surface tension values y~ of n-alkyl methacrylate increase with increasing side chain length: Y L = 23.2 dynes/cm for methyl methacrylate to 33.2 dynes/cm for stearyl methacrylate, but yo values of poly(n-alkyl methacrylate) decrease with increasing side chain length: yc = 36.3 dynes/cm for poly(methy1 methacrylate) to 20.8 dynes/cm for poly(steary1 methacrylate). The decrease in yc is attributed to a tighter packing of the alkyl chain with a greater concentration of the pendent --CHI group at the air/solid interface. Values of yc of copolymers hardly depended on the methacrylonitrile content in copolymers and did not satisfy the equation yc = Nlyc, + Nzycz proposed by Lee. The difference in yc values for casting, annealing, and quenching films of poly(steary1 methacrylate) and the surface structure of copolymers were discussed using electron microscopy and measurement of melting point, heat of melting, and yc.

Characterization of a Poly(2‐oxazoline) Library by High‐Throughput, Automated Contact‐Angle Measurements and Surface‐Energy Calculations

“…All polymers containing 2‐nonyl‐2‐oxazoline monomer have a considerably lower surface energy, in the range of 19–23 mN · m −1 . Similar results have been reported by Litt and Herz, who studied a series of poly( n ‐acyl ethylene imines) with varying alkyl side‐group lengths,12 and Kamagata and Toyama, who studied a series of poly( n ‐alkyl methacrylates) 13. They attributed this effect to a close packing of alkyl chains at the surface.…”

Correlating the mechanical and surface properties with the composition of triblock copoly(2-oxazoline)s

“…13 The surface energy of all diblock copoly(2-oxazoline)s with a poly(2-nonyl-2-oxazoline) block was $21 mN m À1 , while all diblock copolymers without a nonyloxazoline block had a surface energy of $45 mN m À1 . In agreement with other work, [14][15][16] this difference in surface energies was attributed to segregation of the nonyl side-chains to the surface. 13 In the current work, the elastic moduli, surface energies and (surface) phase morphologies of triblock copoly(2-oxazoline)s are presented and related to their chemical composition.…”

Influence of different alkyl side chains on solid surface tension of polymethacrylates

“…The old literature contains critical surface tension values for polymethacrylates with different alkyl side chains. [3][4][5][6] These data point in the same direction as do the newer data. However, they are of unknown reliability, since it has become apparent more recently that many liquids are, from the point of view of contact-angle measurements, incompatible with specific polymers.…”