Polyether Sulfone-Based Epoxy Toughening: From Micro- to Nano-Phase Separation via PES End-Chain Modification and Process Engineering.

The toughness of a high-performance thermosetting epoxy network can be greatly improved by generating polyether sulfone-based macro- to nano-scale morphologies. Two polyethersulfones (PES) which only differ by their chain-end nature have been successively investigated as potential tougheners of a high-Tg thermoset matrix based on a mixture of trifunctional and difunctional aromatic epoxies and an aromatic diamine. For a given PES content, morphologies and toughness of the resulting matrices have been tuned by changing curing conditions and put into perspective with PES chain-end nature.

Biobased Amines: From Synthesis to Polymers; Present and Future.

Amines are key intermediates in the chemical industry due to their nucleophilic characteristic which confers a high reactivity to them. Thus, they are key monomers for the synthesis of polyamides, polyureas, polyepoxydes, which are all of growing interest in automotive, aerospace, building, or health applications. Despite a growing interest for biobased monomers and polymers, and particularly polyamides, it should be noticed that very few natural amines are available. Actually, there is only chitosan and poly(lysine). In this review we present both fundamental and applied research on the synthesis of biobased primary and secondary amines with current available biobased resources. Their use is described as a building block for material chemistry. Hence, we first recall some background on the synthesis of amines, including the reactivity of amines. Second we focus on the synthesis of biobased amines from all sorts of biomass, from carbohydrate, terpenes, or oleochemical sources. Third, because they need optimization and technological developments, we discuss some examples of their use for the creation of biobased polymers. We conclude with the future of the synthesis of biobased amines and their use in different applications.

Structure-properties relationship of biosourced stereocontrolled polytriazoles from click chemistry step growth polymerization of diazide and dialkyne dianhydrohexitols.

The design of dialkyne and diazide functionalized dianhydrohexitol stereoisomers (1-6) afforded a new family of starch-based polytriazoles (7-15) with defined stereochemistry through A(2) + B(2) CuAAC step growth polymerization. The present strategy gave rise to polytriazoles having a high biosourced weight fraction (superior to 60% wt) and exhibiting relatively high molar masses (M(n) = 8-17 kg/mol) that could be easily dissolved in DMF or DMSO. The obtained materials were amorphous and displayed high transition temperatures (T(g) = 125-166 °C) as well as good resistance to thermal degradation (T(d10) = 325-347 °C). Monomer stereochemistry proved to be a crucial parameter aiming at generating polymers with high T(g). Thus, optimal thermal properties were obtained with monomers having RR absolute configuration of the C-2 and C-5 carbon atoms (isomannide configuration).

Click chemistry step growth polymerization of novel alpha-azide-omega-alkyne monomers.

A novel step growth polymerization A-B strategy based on the click chemistry polyaddition of tailor-made alpha-azide-omega-alkyne low molar mass monomers was developed, leading to polytriazole (co)polymers with tunable structures and properties.