Crystallization-controlled structure and thermal properties of biobased poly(ethylene 2,5-furandicarboxylate) (PEF) were studied. The cold-crystallization temperature controlled the structure and thermal properties of the biobased PEF. The melting was complex and evidenced the presence of a significant fraction of less-stable crystals with a low melting temperature that linearly increased with T_c, which formed already during the early stages of crystallization, together with those melting at a higher temperature. Low T_c resulted in the α’-phase formation, less crystallinity, and greater content of the rigid amorphous phase. At high T_c, the α-phase formed, higher crystallinity developed, the rigid amorphous phase content was lower, and the melting temperature of the less-stable crystals was higher; however, slight polymer degradation could have occurred. The applied thermal treatment altered the thermal behavior of PEF by shifting the melting of the less stable crystals to a significantly higher temperature. SEM examination revealed a spherulitic morphology. A lamellar order was evidenced with an average long period and small average lamella thickness, the latter about 3–3.5 nm, only slightly increasing with T_c.

The interest in macromolecular alkoxysilyl-functionalized hybrids (self-assembling or nanostructured), which could be used as precursors in biomimetic silica precipitation and for the synthesis of hollow spherical silica particles, is growing. Nevertheless, reports on all-organosilicon systems for bioinspired silica precipitation are scarce. Therefore, a new kind of polyalkoxysilane macromonomer–linear polysilsesquioxane (LPSQ) of ladder-like backbone, functionalized in side chains with trimethoxysilyl groups (LPSQ-R-Si(OMe)₃), was designed following this approach. It was obtained by photoinitiated thiol-ene addition of 3-mercaptopropyltrimethoxysilane to the vinyl-functionalized polysilsesquioxane precursor, carried out in situ in tetraethoxysilane (TEOS). The mixture of LPSQ-R-Si(OMe)₃ and TEOS (co-monomers) was used in a sol–gel process conducted under acidic conditions (0.5 M HCl/NaCl) in the presence of Pluronic^® F-127 triblock copolymer as a template. LPSQ-R-Si(OMe)₃ played a key role for the formation of microparticles of a spherical shape that were formed under the applied conditions, while their size (as low as 3–4 µm) was controlled by the stirring rate. The hybrid materials were hydrophobic and showed good thermal and oxidative stability. Introduction of zinc acetate (Zn(OAc)₂) as an additive in the sol–gel process influenced the pH of the reaction medium, which resulted in structural reinforcement of the hybrid microparticles owing to more effective condensation of silanol groups and a relative increase of the content of SiO₂. The proposed method shows directions in designing the properties of hybrid materials and can be translated to other silicon–organic polymers and oligomers that could be used to produce hollow silica particles. The established role of various factors (macromonomer structure, pH, and stirring rate) allows for the modulation of particle morphology.

Isotactic polypropylene (iPP), solidified under high-pressure in the orthorhombic γ-form, can exhibit enhanced mechanical properties compared to iPP crystallized in the common monoclinic α-form under atmospheric pressure. The aim of the study was to enhance the mechanical performance of injection-molded iPP and its nanocomposite containing 5 wt% of multiwall carbon nanotubes (MWCNTs) through high-pressure processing, which induced the formation of the γ-phase. Initially, the materials were crystallized in a high-pressure cell. To simulate the conditions during molding, crystallization was carried out by pressurizing the molten polymer to 250 MPa. For comparison, crystallization was also performed during cooling under 200 MPa and 1.4 MPa. Subsequently, the injection molding was conducted under optimized conditions, under pressure of 250 MPa, to promote the formation of the γ-phase, and, for comparison, under 20 MPa, to favor the α-phase formation. The injection-molded nanocomposite crystallized in the γ-form, tested in compression, exhibited an elastic modulus, yield stress, and stress at break higher by approx. 50%, 35% and 40–50%, respectively, compared to injection-molded neat iPP solidified predominantly in the α-form. These results demonstrate that substantial improvements in mechanical performance can be achieved through the incorporation of MWCNTs into iPP and the optimization of high-pressure injection-molding conditions.

Evaporative crystallization of polylactide was modulated by functionalized ladder polysilsesquioxanes through conformational changes in the polyester backbone. Atypical spherulites spontaneously formed a hierarchical 3D superstructure.

Biopolymer-based composites incorporating natural fillers were developed as carriers for various microbiological applications. Three commercially available biodegradable and bio-based polymers: poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and polylactide (PLA)were used as matrices. Brewer’s spent grain (BSG), a by-product of the brewing industry, was employed as a natural filler. A series of biocomposites containing 20, 30, and 40 wt% BSG were fabricated. The structure and thermal properties of the composites were characterized using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Surface properties were evaluated by measuring contact angles with two probe liquids, enabling calculation of surface energy and its polar and dispersive components. In turn, microscopic studies were conducted to evaluate the adhesion and colonization of Metschnikowia andauensis cells on the prepared carriers. The biocontrol activity of the cell–carrier system was assessed using the agar plate method. The results identified the most promising formulations: PHBV with 40 wt% BSG and PLA with 20–40 wt% BSG, especially with 30 wt% BSG. However, the highest biocontrol efficacy among cells adhered to the biocomposite materials was observed with the last one. This study explored the relationship between the physicochemical properties of BSG-filled biopolymers and their suitability for microbial colonization, highlighting their potential as functional carriers for yeast cells.