Investigation of the Side Chain Effect on Gas and Water Vapor Transport Properties of Anthracene-Maleimide Based Polymers of Intrinsic Microporosity

Abstract

In the present work, a set of anthracene maleimide monomers with different aliphatic side groups obtained by Diels Alder reactions were used as precursors for a series of polymers of intrinsic microporosity (PIM) based homo- and copolymers that were successfully synthesized and characterized. Polymers with different sizes and shapes of aliphatic side groups were characterized by size-exclusion chromatography (SEC), (nuclear magnetic resonance) 1H-NMR, thermogravimetric (TG) analysis coupled with Fourier-Transform-Infrared (FTIR) spectroscopy (TG-FTIR) and density measurements. The TG-FTIR measurement of the monomer-containing methyl side group revealed that the maleimide group decomposes prior to the anthracene backbone. Thermal treatment of homopolymer methyl-100 thick film was conducted to establish retro-Diels Alder rearrangement of the homopolymer. Gas and water vapor transport properties of homopolymers and copolymers were investigated by time-lag measurements. Homopolymers with bulky side groups (i-propyl-100 and t-butyl-100) experienced a strong impact of these side groups in fractional free volume (FFV) and penetrant permeability, compared to the homopolymers with linear alkyl side chains. The effect of anthracene maleimide derivatives with a variety of aliphatic side groups on water vapor transport is discussed. The maleimide moiety increased the water affinity of the homopolymers. Phenyl-100 exhibited a high water solubility, which is related to a higher amount of aromatic rings in the polymer. Copolymers (methyl-50 and t-butyl-50) showed higher CO2 and CH4 permeability compared to PIM-1. In summary, the introduction of bulky substituents increased free volume and permeability whilst the maleimide moiety enhanced the water vapor affinity of the polymers.

Highly Breathable and Abrasion-Resistant Membranes with Micro-/Nano-Channels for Eco-Friendly Moisture-Wicking Medical Textiles

“…Considering outdoor textiles are intended to provide comfortable protection, moisture-permeable and breathable performance are indispensable for composite membranes [ 25 , 26 , 27 ]. The comfortable performance was evaluated by air permeability and WVT rate, as illustrated in Figure 7 .…”

Pioneering the preparation of porous PIM-1 membranes for enhanced water vapor flow

“…This facility uses the same “constant volume/variable pressure” measurement method as the time-lag facility, which is widely used to determine gas transport parameters of thick isotropic polymer films. 48 The software of the pressure increase facility is optimized for the characterization of membranes with negligible thickness for which no time-lag can be determined. All membranes were characterized at 40 °C, feed vapor pressure lower than 60 kPa and permeate pressure changing in the range 10–130 Pa.…”

Evidence through Thermal Analysis of Retro Diels-Alder Reaction in Model Networks Based on Anthracene Modified Polyester Resins

“…The reported temperatures for the rDA reaction of furan/maleimide-based polymers do not exceed 150 • C. This fact can be an inconvenience for self-healing polymers that are intended for applications at high temperatures [17]. Anthracene can be an alternative for the diene in the case where the polymers have distinctive structures or where self-healing needs to be functional at elevated temperatures [18][19][20][21][22][23][24]. In the work of B. Gacel et al, graft copolymers were synthesized using anthracene-functionalized polystyrene and maleimido-functionalized poly(ethylene glycol) or poly(methyl methacrylate) [18], but only their glass transition temperatures were reported.…”