Association phenomena of PMMA in solutions and gels

Abstract

Stereocomplex formation of isotactic and syndiotactic polymethylmethacrylate (PMMA) could be demonstrated using X-ray, NMR, and viscosity techniques. In this paper it is shown by measurements of viscosity and investigation of swelling properties that the association of isotactic and syndiotactic sequences of the polymer occurs as well in the solutions and gels of atactic PMMA. From the temperature dependence of the reduced specific viscosity and the swelling it can be deduced that association causes network formation due to microcrystalline regions which have a melting point range. I n solutions of toluene with mixtures of isotactic and syndiotactic PMMA an intermolecular association, with atactic PMMA an intramolecular association is discussed. In chloroform no association could be observed. ZUSAMMENFASSUNG:Die Stereokomplexbildung von isotaktischem mit syndiotaktischem Polymethylmethacrylat (PMMA) konnte aufgrund von rontgenographischen, Kernresonanz-und Viskositatsuntersuchungen nachgewiesen werden. In dieser Arbeit wird mit Hilfe von Viskositatsmessungen und Untersuchungen der Quellungseigenschaften gezeigt, da13 die Assoziation von isotaktischen und syndiotaktischen Sequenzen des Polymeren ebenso in Losungen und Gelen aus ataktischem PMMA auftritt. Aus der Temperaturabhangigkeit der reduzierten spezifischen Viskositat und der Quellung kann hergeleitet werden, da13 die Assoziation die Bildung eines Netzwerkes uber mikrokristdine Bereiche verursacht, die einen Schmelzbereich besitzen. I n verdiinnten Toluol-Losungen von Mischungen aus iso-und syndiotaktischem PMMA wird intermolekulare Assoziation, im ataktischen PMMA intramolekulare Assoziation angenommen. I m Chloroform wurde keine Assoziation beobachtet.

Tacticity in Vinyl Polymers

“…Formation of stereocomplexes between i-PMMA and s-PMMA was first reported by Liquori and co-workers (23). Other factors, such as the polymer concentration (47)(48)(49), mixing ratio (50-52), molecular weight (53)(54)(55), and solvent effect (56,57) of the stereoregular polymers, also affect formation of stereocomplexes between i-PMMA and s-PMMA. In addition, stereocomplexes composed of tactic PMMAs are known to be produced both in bulk and in solution (51)(52)(53).…”

Mechanical Properties and Orientation of Atactic Poly(methyl methacrylate): Sub-Tg Annealing and Stereocomplex Formation

“…[20 -24] As for atactic PMMA, Spevacek et al and Borchard et al proved the formation of the stereocomplex in solution based on NMR results and viscometric experiments, respectively. [15,25,26] In a previous paper, [27] we showed that the stereocomplex formed in films cast from the strongly complexing solvent acetone (A-aPMMA) but not Communication: The mechanical properties and orientation behavior of atactic poly(methyl methacrylate) films cast from acetone (A-aPMMA films) and chloroform (CaPMMA films), with subsequent sub-T g annealing, have been studied. The formation of a stereocomplex in sub-T gannealed A-aPMMA films and C-aPMMA films was demonstrated by means of differential scanning calorimetry.…”

Surface Characterization of Atactic Poly(methyl methacrylate) Aggregates Using Atomic Force Microscopy

“…Spevacek et al and Borchard et al have proved that stereocomplex was able to form in atactic PMMA solutions. [3][4][5] Studying with DSC and FT-IR, 6,7 we also found that a stereocomplex formed in atactic PMMA film from strong complexing acetone, while not in that from noncomplexing chloroform. Stereocomplex in the film derived from the solution from which the film was cast.…”

“…1,2 As for atactic poly(methyl methacrylate), Spevacek et al and Borchard et al proved that stereocomplex was able to form in its solution. [3][4][5] And a stereocomplex was also found in atatic PMMA film from strong complexing solvent acetone. 6,7 In this note, the effects of solvent and substrate on the patterning of a-PMMA aggregates were studied using by atomic force microscopy (AFM).…”