In this work, novel composites based on poly(e-caprolactone) (PCL) were prepared and characterized in terms of morphological, thermal, rheological and mechanical properties. Hollow glass microspheres (HGM), alone or surface modified by treatment with (3-aminopropyl)triethoxysilane (APTES) in order to enhance the compatibility between the inorganic particles and the polymer matrix, were used to obtain lightweight composites with improved properties. The silanization treatment implies a good dispersion of filler particles in the matrix and an enhanced filler–polymer adhesion. The addition of HGM to PCL has relevant implications on the rheological and mechanical properties enhancing the stiffness of the material. Furthermore, the presence of HGM strongly interferes with the crystallization behavior and thermo-oxidative degradation of PCL. The increase of PCL crystallization rate was observed as a function of the HGM amount in the composites. Finally, rotational molding tests demonstrated the possibility of successfully producing manufactured goods in PCL and PCL-based composites on both a laboratory and industrial scale.

https://www.mdpi.com/2073-4360/11/4/624/pdf

Lightweight Poly(ε-Caprolactone) Composites with Surface Modified Hollow Glass Microspheres for Use in Rotational Molding: Thermal, Rheological and Mechanical Properties.

The work deals with the optimization of methane hydrate storage in fixed-bed reactor systems made up of modified silica beads. Under transient conditions, rapid hydrate growth is achieved at 4 °C. Glass beads are modified via silanization and treated with peroxymonosulfuric acid. It is proven that the fixed-bed surface properties significantly determine the gas hydrate growth and final gas uptake and therefore determine the successful technical design of the system. The capillary pressure is calculated in each bed configuration and is set in relation to the overall gas uptake. A negative capillary pressure leads to a holdback of water in the fixed-bed system. A high water-to-hydrate conversion is obtained for an untreated fixed bed with a positive capillary pressure. In the presence of SDS, the capillary effects are negated by the kinetic promotion effects. An inhibiting behavior is observed when using hydrophilic beads after treatment with peroxymonosulfuric acid.

Impact of Modified Silica Beads on Methane Hydrate Formation in a Fixed-Bed Reactor

Development of a Surface‐Active Coating for Promoted Gas Hydrate Formation

Microscopic Particle Contact Adhesion Models and Macroscopic Behavior of Surface Modified Particles

Lightweight polyethylene‐hollow glass microspheres composites for rotational molding technology

Hydrophobic micro-glass particles were obtained by chemical modification with organosilanes. Particles were treated by peroxymonosulfuric acid to obtain a hydrophilic surface, which was the first step of the modification process. Different silanes were used, each of them with a different functional group, effecting variable degrees of hydrophobicity. The successful chemical modification process was established using Fourier transform infrared spectroscopy (FTIR) and water drop interaction with the modified particles surfaces. The morphology of the modified particles was studied using scanning electron microscope (SEM). The degree of the hydrophobicity was established with static contact angle measurements. The microscopic adhesion and particle contact properties of the comparatively stiff (amorphous) micro-glass beads and the macroscopic powder flow behavior were investigated with ring shear tests and evaluated by constitutive models on physical basis.

Katja Mader

Papers

Glass Spheres: Functionalization, Surface Modification and Mechanical Properties