POLYURETHANE/ACRYLATE HYBRIDS: EFFECTS OF ACRYLIC CONTENT AND THERMAL TREATMENT ON POLYMER PROPERTIES

PERUZZO, P.J.; ANBINDER, P.S.; PARDINI, O.R.; COSTA, C.A.; LEITE, C.A.; GALEMBEK, F.; AMALVY, J.I.

JOURNAL OF APPLIED POLYMER SCIENCE

Año: 2009

0021-8995

Polyurethane/acrylate hybrids with different acrylic contents (10, 30, 50, 70 and 90 wt%) were prepared by polymerization of acrylic monomers in the presence of preformed polyurethane chains with polymerizable terminal vinyl groups. Films obtained by casting of polymer dispersions before and after thermal annealing were characterized by DLS, FTIR, TEM, TEM-EELS, DSC and gel fraction determination. SAXS, WAXS, mechanical properties, AFM, water contact angle, Buchholz hardness and roughness of films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM shows that core shell morphology is formed during polymerization. When acrylic content increases, smaller particles without core-shell morphology are observed.  TEM-EELS studies confirm this observation. Systems with up to 50 wt% of acrylic component are homogeneous by SAXS, before and after thermal annealing. Attempting to incorporate a higher amount of acrylic component leads to phase-separated materials with a different morphology, and therefore, different properties. The relationship between acrylic content and properties do not follow a linear behavior.