Nanoporous Crystalline Phases of Poly(2,6-Dimethyl-1,4-phenylene)oxide

Abstract

Crystalline modifications, exhibiting largely different X-ray diffraction\ud patterns, have been obtained for poly(2,6-dimethyl-1,4-phenylene)oxide (PPO), by\ud gel desiccation procedures as well as by solvent-induced crystallization of amorphous\ud films. The choice of the solvent allows controlling the nature of the crystalline phase.\ud Both amorphous and semicrystalline samples of this commercial thermoplastic\ud polymer exhibit a high uptake of large guest molecules (like, e.g., benzene or carbon\ud tetrachloride), both from vapor phases and from diluted aqueous solutions. Surprisingly,\ud the semicrystalline PPO samples present guest solubility much higher than fully\ud amorphous PPO samples. These sorption experiments, as well as density measurements\ud and classical BrunauerEmmettTeller (BET) experiments, clearly indicate\ud that the obtained PPO crystalline phases are nanoporous. For these thermally stable\ud PPO-based materials exhibiting nanoporous crystalline and amorphous phases, many\ud applications are predictable

Microporous-crystalline microfibers by eco-friendly guests: An efficient tool for sorption of volatile organic pollutants

“…In addition to these microporous polymer materials, the formation of microporouscrystalline forms (often referred as nanoporous crystalline forms in the literature), presenting a density lower than the corresponding amorphous phase, have been also discovered for two industrially relevant polymers: syndiotactic polystyrene (s-PS) [10][11][12][13][14][15][16][17] and poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) [18][19][20][21].…”

Crystalline Nanoporous Materials Based on Poly(2,6‐dimethyl‐1,4‐phenylene)oxide

“…The diffraction data reported in Figure indicate that, depending on the solvent, different crystalline phases can be obtained after solvent removal from the gels. It is worth adding that additional crystalline phases have been obtained after treatment with supercritical carbon dioxide of PPO gels prepared in other solvents such as α‐pinene, 1,2‐dichloroethane, tetralin,……”

“…Very recently it has been shown that poly(2,6‐dimethyl‐1,4‐phenylene)oxide (PPO) can also form various nanoporous crystalline phases presenting much higher solubility of many guests (e.g., benzene, CCl 4 , CO 2 , methane, propane, and propene) than fully amorphous PPO. Moreover with respect to s‐PS, PPO presents the advantage to also possess a high melting temperature of the nanoporous crystalline phases at c.a.…”

Nanoporous Semicrystalline Syndiotactic Polystyrene with Sulfonated Amorphous Phase, for a Fast and Efficient Removal of VOC Pollutant Traces From Water

“…While the preparation and the characterization of amorphous nanoporous polymeric materials such as hyper‐cross‐linked polymer networks (HCPs) or linear rigid polymers with intrinsic porosity (PIMs) are well‐documented in the literature the existence of nanoporous polymeric crystalline phases has been described so far only for syndiotactic polystyrene (s‐PS) and poly(2,6‐dimethyl‐1,4‐phenylene ether) (PPO) . These commercially available thermoplastic polymers are able to form co‐crystalline phases with several low‐molecular‐mass guest molecules which, in turn, by suitable guest extraction procedures, can give nanoporous crystalline forms.…”