Agurtzane Mugica

• University of the Basque Country

Neodymium‐iron‐boron (NdFeB) magnets are essential because they show optimized magnetic properties for clean energy applications. They suffer nevertheless from their rare earth mine security of supply. The European Union considers them as key materials, encouraging their recycling to reduce the supply dependence on other countries. In this work, bi...

The effect of lignin nanoparticles (LNPs) on the crystallization kinetics of poly(ethylene oxide) (PEO) is examined. Lignin from spruce and ionic isolation was used to prepare LNPs with a number-averaged diameter of 85 nm (with a relatively large polydispersity) by an ultrasonication method. PEO-based nanocomposites with four different LNP contents...

Poly (butylene succinate) (PBS) and polycaprolactone (PCL) are two immiscible biocompatible and biodegradable polymers. Aiming to combine the properties of these biodegradable polymers, this work explores for the first time blending PBS or PCL with PBS-ran-PCL copolymers (BSxCLy) at 75/25, 50/50, and 25/75 wt% compositions, with various copolymer c...

The recyclability of opaque PET, which contains TiO2 nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological prop...

The morphology and crystallization behavior of two triblock terpolymers of polymethylene, equivalent to polyethylene (PE), poly (ethylene oxide) (PEO), and poly (ε-caprolactone) (PCL) are studied: PE227.1-b-PEO4615.1-b-PCL3210.4 (T1) and PE379.5-b-PEO348.8-b-PCL297.6 (T2) (superscripts give number average molecular weights in kg/mol and subscripts...

Polylactide is one of the most versatile biopolymers, but its slow crystallization limits its temperature usage range. Hence finding ways to enhance it is crucial to widen its applications. Linear and cyclic poly (l-lactide) (l-PLLA and c-PLLA) of similarly low molecular weights (MW) were synthesized by ring-opening polymerization of l-lactide, and...

In the present study, the dielectric properties of both neat and plasticized polylactide submitted to repeated extrusion and injection processes to simulate recycling were analysed. The dielectric relaxation spectrum, consisting of β and α relaxation, revealed the relevance of both acryl-PEG based plasticization and thermo-mechanical degradation in...

In this work, we study for the first time, the isothermal crystallization behavior of isodimorphic random poly(butylene succinate)-ran-poly(ε-caprolactone) copolyesters, PBS-ran-PCL, previously synthesized by us. We perform nucleation and spherulitic growth kinetics by polarized light optical microscopy (PLOM) and overall isothermal crystallization...

Titanium dioxide (TiO2) nanoparticles have recently appeared in PET waste because of the introduction of opaque PET bottles. We prepare polymer blend nanocomposites (PBNANOs) by adding hydrophilic (hphi), hydrophobic (hpho), and hydrophobically modified (hphoM) titanium dioxide (TiO2) nanoparticles to 80rPP/20rPET recycled blends. Contact angle mea...

A detailed isothermal crystallization study of biobased and biodegradable isodimorphic poly (butylene succinate-ran-butylene azelate) random copolyesters (PBS-ran-PBAz) with a wide composition range has been carried out to determine nucleation kinetics, spherulitic growth rates and overall crystallization kinetics. Differential Scanning Calorimetry...

Poly(lactide)/poly(ε-caprolactone) blends (PLA/PCL) with composition 80/20 (w/w%) are immiscible but biodegradable and therefore often studied in the literature. We have prepared 80/20 PLA/PCL blends with and without poly(ε-caprolactone)-co-poly(carbonate) copolymers (block and random). The blends were prepared both by melt extrusion and by solutio...

High molecular weight poly[(butylene succinate)-ran-(ϵ-caprolactone)] copolyesters (PBS-ran-PCL) were synthesized in a wide composition range and compared with significantly lower molecular weight samples synthesized previously. DSC and WAXS showed that these copolyesters are isodimorphic (i.e., each crystalline phase contains a small amount of the...

Ring closure click chemistry methods have been used to produce cyclic c-PLLA and c-PDLA of a number-average molecular weight close to 10 kg/mol. The effects of stereochemistry of the polymer chains and their topology on their structure, nucleation, and crystallization were studied in detail employing wide-angle X-ray scattering (WAXS), small-angle...

This work focused on the determination of crystallization kinetics of neat polylactide (PLA) and a plasticized grade of PLA obtained by reactive extrusion (pPLA), as a function of thermomechanical recycling. In particular, the materials were submitted to repeated extrusion and injection procedures to simulate recycling. Prior reprocessing, spheruli...

Morphology and crystallization of block copolymers are influenced by their chemical nature, microstructure, composition, and segregation strength between blocks. The crystallization conditions play an important role in the final structure and physical properties of the material. This chapter reviews recent literature on the morphology and crystalli...

Accelerating the crystallization rate of Polylactide (PLA) to extend its application range is an interesting challenge. In this work, the crystallization of PLA from the glassy state within 80/20 PLA/PCL blends, with or without the addition of three different compositions of Poly(L-Lactide-block-Carbonate), PLA-b-PC diblock copolymers, is investiga...

Poly(butylene succinate-ran-butylene azelate) random copolyesters (PBS-ran PBAz) were studied using broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC). These copolymers are characterized by being isodimorphic and by displaying a eutectic behavior. Depending on their composition, the PBS-rich phase, the PBAz-rich pha...

Nanocomposites based on polycarbonate (PC) and different amounts of untreated graphene nanoplatelets (GnP) (from 1 to 7 wt %) were prepared by melt blending. The nanocomposites were thoroughly characterized employing the following techniques: broad band dielectric spectroscopy, thermally stimulated depolarization currents, differential scanning cal...

Poly(butylene succinate-ran-butylene azelate) random copolyesters were thermally fractionated by successive self-nucleation and annealing (SSA). The samples before and after SSA were analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (WAXS and SAXS). WAXS results indicate that a small degree of comonomer inclusion is present...

The synthesis of symmetric cyclo poly(ε-caprolactone)–block–poly(l(d)-lactide) (c(PCL–b–PL(D)LA)) by combining ring-opening polymerization of ε-caprolactone and lactides and subsequent click chemistry reaction of the linear precursors containing antagonist functionalities is presented. The two blocks can sequentially crystallize and self-assemble i...

Hydrolytic degradation of a nanocomposite of poly(L-lactic acid), PLA, and a layered double hydroxide (LDH) modified with the drug 4-biphenyl acetic acid (Bph) has been studied. PLA/LDH-Bph nanocomposite was prepared by solvent casting with 5 wt % of drug modified LDH and the hydrolytic degradation was carried out in a PBS solution at pH 7.2 and 37...

The structure and thermal properties of linear low-density polyethylene (LLDPE)/medium soft paraffin wax blends, prepared by melt mixing, were investigated by differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS and WAXS). The blends form a single phase in the melt as determined by SAXS. Upon cooling from the mel...

The effect of adding Poly(lactide-ran-caprolactone), P(LA-ran-CL), random copolymers to melt mixed Poly(lactide)(PLA)/Poly(ε-caprolactone)(PCL) 80/20 blends is investigated. The concentration of P(LA-ran-CL) copolymer added to the blends was 2 wt% and two different types of P(LA-ran-CL) copolymers were employed. They varied in composition and molec...

The sequential crystallization of poly(ethylene oxide)-b-poly(ε-caprolactone)-b-poly(L-lactide) (PEO-b-PCL-b-PLLA) triblock terpolymers, in which the three blocks are able to crystallize separately and sequentially from the melt, is presented. Two terpolymers with identical PEO and PCL block lengths and two different PLLA block lengths were prepare...

Employing the hydroxyl groups on the surface of Cloisite® 30B montmorillonite (Cl30B), the ring-opening polymerization of l-lactide was performed with a metal-free catalyst to yield a PLLA-g-Cl30B nanohybrid with low Mn grafted PLLA chains (i.e., 9 kg mol⁻¹). This nanohybrid was then melt mixed with PLA 4032D from NatureWorks, which is a slow-cryst...

The effect of chain topology (ring versus linear polymer chains) on polymer crystallization is reviewed. Recent advances in ring closure and ring expansion synthetic techniques have made available a range of well-characterized samples with higher levels of purity than available decades ago. Cyclic molecules are fascinating because the structural di...

Self-nucleation (SN) is a special nucleation process triggered by self-seeds or self-nuclei that are generated in a given polymeric material by specific thermal protocols or by inducing chain orientation in the molten or partially molten state. SN increases the nucleation density of polymers by several orders of magnitude, producing significant mod...

The structure, morphology, and thermal properties of biobased and biodegradable poly(butylene succinate-ran-butylene azelate) random copolyesters with a wide composition range were studied. These PBS-ran-PBAz copolymers can crystallize in the entire composition range despite being random, displaying a eutectic point when their melting point is plot...

The influence of organoclays on the thermal decomposition pathway of poly(hydroxyl ether of bisphenol A) (Ph) was analysed under nitrogen and air. In the two clays employed, montmorillonite and vermiculite, the organic clay modifier, a polar alkylammonium surfactant, led to different interlayer arrangements. Nanocomposite formation was established...

Isothermal crystallization of nanocomposites of poly(p-dioxanone) and layered double hydroxides (unmodified or oganically modified) prepared by melt extrusion has been studied by Dynamic Scanning Calorimetry and Optical Microscopy. Although the nanoclay acts as a nucleating agent, the spherulite growth rate of the nanocomposites decreases due to th...

The nature and the extent of degradation of poly(hydroxy ether of bisphenol-A) phenoxy resin were analysed by thermogravimetry (TGA/DTGA) under nitrogen and air atmosphere. Decomposition kinetics were elucidated according to Flynn–Wall–Ozawa, Friedman and Kissinger methods. The evolved gases during degradation were inspected by a thermogravimetry a...

Nanocomposites of poly(p-dioxanone) (PPDO) with unmodified and organically modified layered double hydroxide (LDH) have been prepared by melt extrusion method. Dodecyl sulfate was used as organic modifier. The morphology of nanocomposites was analyzed by X-ray diffraction and transmission electron microscopy and their thermal properties by differen...

Novel composites based on poly(p-dioxanone) (PPDO) and organically modified cationic and anionic clays have been prepared using the technique of melt-extrusion. The intercalation of the organic modifier in the clays and the dispersion degree of the organically modified clays in the PPDO composites have been analyzed by wide-angle X-ray scattering (...

Electrically conducting blends, based on polypyrrole (PPy) as the conductive polymer and poly(ɛ-caprolactone) (PCL) as an insulating polymeric matrix, were prepared by polymerizing pyrrole (Py) in its vapor state inside the PCL matrix. The roles of specific interactions between blend components as well as the crystallization of PCL matrix in the re...

The employment of used tyres as a new source of raw materials for different applications can be a partial solution to the great environmental problems generated by these products concerning their disposal at waste depots. In this study, high-resolution thermogravimetric analysis (Hi-Res TGA) is used to quantify the elastomer composition of SBR/NR i...

The influence of microstructure on thermal degradation behaviour was studied in five samples of pure poly(vinyl chloride) (PVC) obtained at different polymerisation temperatures. Tacticity of the samples was characterized by Fourier transform infrared spectroscopy (FTIR), and their thermogravimetric behaviour was measured by high resolution (Hi-Res...

The miscibility in blends of poly(cyclohexyl methacrylate) (PCHMA) with poly(4-vinyl phenol) (PVPh) and with copolymers containing vinyl phenol and styrene units (PSVPh) has been examined by Fourier transform infrared spectroscopy. The phase behaviour of the PCHMA/PSVPh system was predicted by means of association model of Painter and Coleman (PCAM...

The miscibilities of some styrene derivatives (polystyrene (PS), poly(p-methylstyrene) (PPMS) and poly(p-vinyl phenol) (PVPh)) with poly(cyclohexyl methacrylate) (PCHMA) have been compared by studying their compositional variation of glass-transition temperatures (Tg). The mixtures of PS and PPMS with PCHMA were found to be miscible over the full c...

The phase behaviour and interaction parameters of binary blends of copolymers involving cyclohexyl methacrylate (CHMA), methyl methacrylate (MMA) and various styrene derivatives (styrene (S), α-methylstyrene (AMS) and p-methylstyrene (PMS)) are examined using the lattice fluid theory of Sanchez and Lacombe. ‘Bare’ interaction parameters (ΔP∗ij) for...

The phase behavior of binary blends of poly(cyclohexyl methacrylate-co-methyl methacrylate) (P(CHMA-co-MMA)) copolymers with poly(α-methylstyrene) (PAMS) and poly(p-methylstyrene) (PPMS) has been determined experimentally and compared to that of the P(CHMA-co-MMA)/PS system. The enthalpic and entropic parts of the segmental interaction parameter fo...

Modeling of the lower critical solution temperature, LCST, phase boundary of binary blends of poly(styrene) (PS) and random poly(cyclohexyl methacrylate-co-methyl methacrylate) copolymers was carried out incorporating temperature-dependent segmental interaction parameters, χij(T), into the classical mean field binary interaction model. By using lit...

Employing segmental interaction densities (Bij's) determined by means of analogue calorimetry, a binary interaction model based on the Flory−Huggins theory predicts the miscibility of poly(ethylene oxide) (PEO) with poly(methyl methacrylate-co-ethyl methacrylate) [P(MMA-co-EMA)] copolymers having high methyl methacrylate contents. The miscibility b...