Antonius Broekhuis

Optimisation of a green gas supply chain--a review.

In this review the knowledge status of and future research options on a green gas supply based on biogas production by co-digestion is explored. Applications and developments of the (bio)gas supply in The Netherlands have been considered, whereafter literature research has been done into the several stages from production of dairy cattle manure and biomass to green gas injection into the gas grid. An overview of a green gas supply chain has not been made before. In this study it is concluded that on installation level (micro-level) much practical knowledge is available and on macro-level knowledge about availability of biomass. But on meso-level (operations level of a green gas supply) very little research has been done until now. Future research should include the modeling of a green gas supply chain on an operations level, i.e. questions must be answered as where to build digesters based on availability of biomass. Such a model should also advise on technology of upgrading depending on scale factors. Future research might also give insight in the usability of mixing (partly upgraded) biogas with natural gas. The preconditions for mixing would depend on composition of the gas, the ratio of gases to be mixed and the requirements on the mixture.

Understanding the role of plasticisers in spray-dried starch

Amorphous thermoplastic starch (TPS) films were produced by compression moulding of solution spray-dried TPS powder and by direct solution casting. Oxidised potato starch was used as a feedstock for production of plasticised formulations containing glycerol or urea, or their combinations with maltodextrin (DE=19.1) as processing aid. The crystallinity index of freshly moulded films made from solution spray-dried powder was significantly lower than that for casted films. FTIR analysis showed that starch interacted in hydrogen bond formation with glycerol and urea plasticisers, reducing the glass transition temperature to 136 °C and 106 °C, respectively. Formulations containing maltodextrin did not show a Tg. Glycerol-plasticised and co-plasticised films immediately started to retrogradate in the presence of moisture, while urea based systems only showed slow recrystallization at the highest moisture exposure. In line with retrogradation behaviour, urea plasticised and co-plasticised films exhibited a more ductile behaviour, whereas glycerol based ones showed more brittle behaviour.

The effect of hydrophilic and hydrophobic block length on the rheology of amphiphilic diblock Polystyrene-b-Poly(sodium methacrylate) copolymers prepared by ATRP

Following our previous investigation on the effect of molecular architecture on the rheology of Polystyrene-b-Poly(sodium methacrylate) copolymers (PS-b-PMAA), we consider here diblock PS-b-PMAA copolymers characterized by a different length of either the hydrophilic or the hydrophobic block. Various copolymers characterized by different PS or PMAA block length have been prepared by ATRP (kinetics is also discussed) and studied from the point of view of their rheological behaviour in water. To the best of our knowledge, this is the first systematic investigation concerning the effect of block length on the rheology of diblock polyelectrolytes. We found that the hydrophobic block length has small influence on the rheology. Surprisingly, the polymers with shortest PMAA blocks yield the strongest gels at high concentration. A simple model based on the classical theories of self-assembly and percolation of amphiphilic polymers has been here developed in order to explain the observed data.

An easy synthetic way to exfoliate and stabilize MWCNTs in a thermoplastic pyrrole-containing matrix assisted by hydrogen bonds

This work focuses on the design of an engineered thermoplastic polymer containing pyrrole units in the main chain and hydroxyl pendant groups (A-PPy-OH), which help in achieving nanocomposites containing well-distributed, exfoliated and undamaged MWCNTs. The thermal annealing at 100 °C of the pristine nanocomposite promotes the redistribution of the nanotubes in terms of a percolative network, thus converting the insulating material in a conducting soft matrix (60 μΩ m). This network remains unaltered after cooling to r.t. and successive heating cycles up to 100 °C thanks to the effective stabilization of MWCNTs provided by the functional polymer matrix. Notably, the resistivity–temperature profile is very reproducible and with a negative temperature coefficient of −0.002 K−1, which suggests the potential application of the composite as a temperature sensor. Overall, the industrial scale by which A-PPy-OH can be produced offers a straightforward alternative for the scale-up production of suitable polymers to generate multifunctional nanocomposites.

Study of Synthesis of Novel ɤ-Valerolactone-Based Polyurethanes

The ring opening of -valerolactone (GVL) with amine compounds was reported as a promising molecular engineering tool to synthesize precursors for new bio-based polymers such as polyurethanes (PUs). Experimental work on the synthesis of polymers based on GVL/1,2-ethanolamine and GVL/1,2-diaminoethane adducts, and di-isocyanates (1,4-phenylene-di-isocyanate (PDI) 2,4-toluene-di-isocyanate (TDI) and hexamethylene-di-isocyanate (HDI)) is described. The polymers were characterized by FTIR, 1H-NMR, 13C-NMR, elemental analysis and GPC. The best polymerization results were obtained using TEA as the catalyst, DMA as the solvent and a temperature of 140°C for the reaction of the GVL/1,2-aminoethanol adduct with TDI. A polymer with a molecular weight (Mw) of 156 KDalton was produced in 97% yield.

Structure - Mechanical and Thermal Properties Relationship of Novel gamma-Valerolactone-Based Polyurethanes

Polymerization of biomass-based diol precursors such as N,N’-1,2-ethanediylbis-(4-hydroxy-pentanamide) and 4-hydroxy-N-(2-hydroxyethyl)-pentanamide with aliphatic (hexamethylene diisocyanate, HDI) and aromatic di-isocyanates (1,4-phenylene-di-isocyanate, PDI and 2,4-toluene-di-isocyanate,TDI) resulted in some novel polyurethanes. The diol precursors were obtained from the ring opening of γ-valerolactone, GVL, with amine compounds reported as a promising molecular engineering tool to synthesize precursors for new biobased polymers. An interesting investigation about the relationship between structures of the diols and properties such as thermal and mechanical behavior of the obtained polyurethanes was reported in this article. Observation of thermal properties of the polymers showed that the polyurethanes are amorphous and thermally stable until 250°C, with a maximum glass transition temperature of 128°C. The polymer with the highest molecular weight, i.e., 147 kD for the polyurethane made from TDI and 4-hydroxy-N-(2-hydroxyethyl)-pentanamide, showed a high elastic modulus (2,210 MPa), which brings this bio-based system within the window of commercial polyurethane applications. GRAPHICAL ABSTRACT

Diels–Alder-Crosslinked Polymers Derived from Jatropha Oil

Methyl oleate, methyl linoleate, and jatropha oil were fully epoxidized using in situ-generated performic acid. The epoxidized compounds were further reacted with furfurylamine in a solvent-free reaction to obtain furan-functionalized fatty esters which, then, functioned as oligomers for a network preparation. Thermoreversible crosslinking was obtained through a (retro) Diels–Alder reaction with bismaleimide, resulting in the formation of a brittle network for furan-functionalized methyl linoleate and jatropha oil. The furan-functionalized fatty esters were mixed with alternating (1,4)-polyketone reacted with furfurylamine (PK-Furan) for testing the mechanical and self-healing properties with DMTA and DSC, respectively. Full self-healing properties were found, and faster thermoreversibility kinetics were observed, compared to PK-Furan.

Water-swellable elastomers: synthesis, properties and applications

Abstract Water-swellable elastomers (WSE) constitute a class of rubbery materials that have been widely studied both in academia and industry during the last 25 years. Market pull is the major driver for the exploration of these materials. The need of WSE in several sealing applications has driven the attention of many academic researchers toward the possibility to provide a rubber with water-swelling characteristics. As commercial rubbers are hydrophobic materials, making them swell in water presents an interesting and difficult challenge. This paper reviews the scientific and patent literature on the fundamental aspects of WSE: the various synthetic approaches, the properties of the corresponding polymers (not only the swelling performance but also the mechanical behavior), and some of their applications. Particular attention is paid to the chemical structure/performance relationships of WSE. Finally, the authors speculate on a great future for WSE that can be rationally designed for improved and/or new applications.