Sulfonation of syndiotactic polystyrene for model semicrystalline ionomer investigations

Abstract

Syndiotactic polystyrene was lightly sulfonated in 1,2,4-trichlorobenzene using acyl sulfate complexes. The sulfonation efficiency of the acyl sulfate increased significantly when anhydrides containing long aliphatic groups were used to complex sulfuric acid. The high sulfonation efficiencies, relative to acetyl sulfate, were attributed to the increased solubility of the longer hydrocarbon complexes in trichlorobenzene. The incorporation of small quantities (less 3.4 mol %) of sulfonic acid groups onto the syndiotactic polystyrene backbone was found to have little effect on the glass transition temperatures of these new materials. However, a much more pronounced effect of sulfonation was observed in the ionomer crystallization. Increasing the level of sulfonation decreased the melting point, degree of crystallinity, and apparent rate of crystallization due to a rejection of sulfonated styrene units from the crystalline domains.

Synthesis of 4-tert-butyldimethylsilyloxystyrene and its copolymerization with styrene using (η5-indenyl)trichlorotitanium in the presence of methylaluminoxane

“…After extraction of the crude product using acetone for Scheme 1: 48 h in order to remove the amorphous polymer fraction, the 1 H and 13 C NMR spectra of the final product are shown in Fig. 2.…”

“…Furthermore, the presence of a single sharp resonance at d = 145 ppm assigned to the quaternary carbon C-1 of the phenyl ring clearly indicates that this polystyrene copolymer is highly syndiotactic. Although it seems to be possible to calculate the fraction of the mmmm or rrrr pentad configuration from the 13 C NMR spectrum 8) , it is difficult to determine the randomness of two monomer units in the formed polymer backbone by an NMR analysis b . The melting temperature was observed at 253 8C from differential scanning calorimetry c .…”

“…However, considering a very high reactivity of IndTiCl 3 for the syndiospecific polymerization of styrene 25) , the observed molecular weight is The T g (glass transition temperature), the crystallization temperature (T c ), and the melting temperature (T m ) were observed at 95, 158 and 253 8C, respectively, in the DSC thermogram using a Perkin-Elmer DSC-7 instrument, in a manner similar to sulfonated syndiotactic polystyrene in ref. 13) (20 8C/min, 2 nd scan)…”

“…Functionalized syndiotactic polystyrene is expected to play an important role to overcome the limited end-uses of syndiotactic polystyrene by improving the compatibility with other polymers via physical interaction or chemical bonding. Up to date, there are few reports on the functionalization of syndiotactic polystyrene except for sulfonated syndiotactic polystyrene 12,13) . In this respect, the synthetic challenges for functionalized copolymers involving syndiotactic polystyrene seem to open a new era to expand the application field.…”

Structure–property relationships for sulfonated poly(butylene terephthalate)

“…1 While considerable effort has gone into the study of semicrystalline ionomers, such as polyethylene ionomers 1 and syndiotactic polystyrene ionomers, 3,4 very little work has been reported on the properties of PBT ionomers (PBTIs). [5][6][7] The objective of the work described in this document was to develop structure-property relationships, relating the compositional variables of PBTIs to the polymer properties.…”