Isomorphic Polyoxyalkylene Copolyethers Obtained by Copolymerization of Aliphatic Diols

Abstract

Isomorphism in random copolymers occurs when comonomer units can crystallize within a single crystalline lattice in the entire composition range. This ideal behavior is rare in random copolymers and only a few examples of isomorphism are found in copolyesters and copolycarbonates. In this work, we show a series of polyoxyalkylenes copolyethers obtained by copolymerization of 1,6hexanediol and 1,12-dodecanediol which are able to crystallize in the entire composition range and display an isomorphic behavior. The copolymers were synthesized via a bulk selfcondensation method at high temperature, using a thermally stable Non-Eutectic Mixture Organocatalyst (NEMO) prepared from methanesulfonic acid (MSA) and 1,5,7triazabicyclo[4.4.0]dec-5-ene (TBD). The final molar ratios of the copolyethers were calculated by 1 H NMR spectroscopy and the random distribution of the two monomeric units was confirmed by 13 C NMR spectroscopy. The effect of the composition of comonomer units on the crystalline structure was investigated by DSC and WAXS. The two comonomeric units along the chain can co-crystallize regardless of the composition, while displaying melting point values that vary linearly in between those of the parent homopolymers (54,9 and 84,7 °C). The crystalline reflections given by WAXS demonstrated that the two comonomers are miscible in the crystalline state and meet the general criteria to be regarded isomorphic random copolymers. Finally, a random terpolymer was synthetized from 1,6-hexanediol, 1,10-decanediol and 1,12-dodecanediol, which also shows a single melting temperature, thus demonstrating the versatility of the polymerization route employed.

Unsaturated Poly(ester-urethanes) with Stereochemically Dependent Thermomechanical Properties

“…block or multiblock copolymers). [37][38] In a previous study of semicrystalline materials possessing a similar thermal profile, the lower temperature melt transition was correlated to short range crystalline ordering and the higher temperature transitions to overall longer range order in the system. 36,39 Comparing C100 and T100 (or S100) it is possible that the disorder introduced by the cis moiety prevents the longer range order that may be observed in the latter.…”

From Lab to Market: Current Strategies for the Production of Biobased Polyols

“…All of these advantages make this procedure a sustainable and scalable alternative for the synthesis of medium and long chain aliphatic and aromatic polyether polyols. Because this reaction is controlled, the resulting polymers show tunable properties with molar masses ranging from 400 to 10 000 g·mol –1 and morphology ranging from amorphous to semicrystalline materials with low T g (from −62 to −50 °C) …”

“…Because this reaction is controlled, the resulting polymers show tunable properties with molar masses ranging from 400 to 10 000 g•mol −1 and morphology ranging from amorphous to semicrystalline materials with low T g (from −62 to −50 °C). 138 When moving from the laboratory scale to industrially relevant polymerization conditions, challenges had to be overcome. In the laboratory, the reaction was performed on a scale of 10 g using a Schlenk line while the temperature gradient was manually controlled.…”

Polyether Single and Double Crystalline Blends and the Effect of Lithium Salt on Their Crystallinity and Ionic Conductivity

“…The reflections of neat PEO are observed at 19.4 • and 23.45 • , which are assigned to the (120) and (112) planes, respectively [33][34][35], and the reflections of neat PHD are presented at 19.85 • and 24.29 • , and are assigned to the (020) and (110) planes, respectively [36,37]. The blends 80/20, 60/40, 50/50 PEO/PHD show the peaks of both crystalline structures without any changes in the 2θ angles, which indicates the two phases crystallize separately and without any modification of the crystalline structure of the neat blend components.…”