Miniemulsion copolymerization of n‐butyl methacrylate and crosslinking monomers such as a macromonomer crosslinker (Mac), ethylene glycol dimethacrylate (EGDMA), or an aliphatic urethane acrylate macromonomer (AUA) was utilized to obtain crosslinked latex particles. The crosslinking monomers were added at 0.2 mol %, on the basis of the amount of n‐butyl methacrylate utilized in a polymerization. The development of the gel content during the copolymerization reaction differs depending on the type of the crosslinking monomer. In addition to the crosslinking reactions between the n‐butyl methacrylate and the crosslinking monomers, other kinetic events, such as microphase separation, may have occurred, giving rise to different particle morphologies, dependent on the type of initiator used (i.e., oil‐soluble or water‐soluble). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1721–1730, 2001

Miniemulsion copolymerization of n-butyl methacrylate and crosslinking monomers such as a macromonomer crosslinker (Mac), ethylene glycol dimethacrylate (EGDMA), or an aliphatic urethane acrylate macromonomer (AUA) was utilized to obtain crosslinked latex particles. The crosslinking monomers were added at 0.2 mol %, on the basis of the amount of n-butyl methacrylate utilized in a polymerization. The development of the gel content during the copolymerization reaction differs depending on the type of the crosslinking monomer. In addition to the crosslinking reactions between the n-butyl methacrylate and the crosslinking monomers, other kinetic events, such as microphase separation, may have occurred, giving rise to different particle morphologies, dependent on the type of initiator used (i.e., oil-soluble or water-soluble).

Films obtained from copolymer latexes of n-butyl methacrylate (BMA) with a series of crosslinking monomers [i.e., a macromonomer crosslinker (Mac), ethylene glycol dimethacrylate (EGDMA), and aliphatic urethane acrylate] exhibited differences in their tensile properties and swelling behaviors. For P(BMA-co-EGDMA) copolymer, a dependence on the initiator type was obtained. It is postulated that the network microstructures for the various copolymers evolved as the result of the copolymerization reactions between the monomer pairs during the synthesis in the miniemulsion free-radical copolymerization. These network microstructures are, therefore, hypothesized to influence the mechanical properties of the resultant films. Copolymers prepared with Mac were tough in comparison with copolymers made with EGDMA. The presence of longer linear or lightly crosslinked poly(n-butyl methacrylate) (PBMA) chains and the looseness of the crosslinked network structures in the PBMA-co-Mac copolymers appear to be the factors responsible for the differences. All of the copolymer films disintegrated into swollen individual microgels when they were immersed in tetrahydrofuran.

A macromonomer crosslinker was synthesized by reacting an hydroxy‐terminated ethylene–butylene diol copolymer with an excess of acrylic acid in toluene. 1H‐, 13C‐, and attached proton test (APT) NMR, Fourier transform IR, and gel permeation chromatography were used to characterize the macromonomer crosslinker. Its dilute solution behavior was also compared with the base diol. The addition of the ester moiety to the copolymer backbone did not involve any other side reactions, as evidenced by the similarities in the structures of the macromonomer crosslinker and the diol. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1362–1368, 2000