Film Formation and Polymer Diffusion in Poly(vinyl acetate-co-butyl acrylate) Latex Films. Temperature Dependence

Abstract

We describe polymer diffusion measurements in a poly(vinyl acetate) copolymer latex film by fluorescence decay measurements of nonradiative energy transfer (FRET). The base monomer is a 4:1 weight ratio copolymer of vinyl acetate and butyl acrylate P(VAc-BA) with a glass transition temperature of ca. 12 °C. P(VAc-BA) latex particles labeled with phenanthrene (Phe) as the donor and with 4-(N,Ndimethylamino)benzophenone (NBen) as the acceptor were prepared by semicontinuous emulsion polymerization. Latex films were cast from a 1:1 mixture of Phe-and NBen-labeled latex samples. First, a series of films containing NBen-labeled latex samples with different NBen levels were annealed at 45 °C, showing that NBen levels have no influence on the rate of polymer diffusion in P(VAc-BA) latex films. From the fully mixed solvent-cast films, the characteristic distance for energy transfer between Phe and NBen (the Fo ¨rster radius R0) was obtained as 2.44 nm. Then, polymer diffusion was monitored as a function of annealing temperature in latex films containing Phe-labeled latex with 1 mol % PheMA and NBen-labeled latex with 0.3 mol % of the NBen chromophore. The temperature dependence of the diffusion rate (from 35 to 75 °C) was characterized by an effective activation energy Ea ) 34 ( 0.5 kcal/ mol. In parallel, an effective Ea ) 34 kcal/mol was obtained from viscoelastic relaxation measurements over a range of temperatures close to those of the diffusion experiments.

The onset of polymer diffusion in a drying acrylate latex: how water initially retards coalescence but ultimately enhances diffusion

“…24 Here, we use an identical approach to quantify how diffusivity increases with increasing humidity over long aging times. We first selected the data at RH = 23% for each latex as the reference data for the master curve analysis.…”

Tracking high molecular weight polymer interdiffusion on a SERS‐based platform

“…For high molecular weight polymers, characteristic diffusion distances that define the interfacial structure are in the range of tens to hundreds of nanometers. Several techniques which high‐spatial resolution (<100 nm) have been employed to investigate the topic, such as Forward Recoil Spectrometry, Nuclear Reaction Analysis or Fluorescence Resonance Energy Transfer, along with many others recently developed . With these techniques, diffusion coefficients below 10 −14 cm 2 /s have been typically measured.…”

Effect of alkali-soluble resin emulsifiers on coalescence and interdiffusion between latex polymer particles

“…The polymer interdiffusion process was monitored following the evolution of the fluorescence decay profile I D (t). The results were given in terms of the quantum efficiency of energy transfer (ϕ ET ), which is related to the fraction of molecular mixing in a system of labelled particles, and it is defined as [25][26][27][28]:…”