Chuanhui Gao

Application of Poly(butylenes 2-methylsuccinate) as Migration Resistant Plasticizer for Poly(vinyl chloride)

The bio-based and biodegradable polyester poly(butylenes 2-methylsuccinate) (PBM) was successfully used as a polymeric plasticizer to modify poly(vinyl chloride) (PVC) in this work. The tensile properties, plasticization efficiency estimated by the lowered glass transition temperature and the enhanced elongation at break of the PVC/PBM blends and the migration stability of the PBM were investigated. It was indicated that the migration-resistant property of PVC plasticized with PBM was greatly superior to that with dioctyl phthalate (DOP). Furthermore, the tensile properties were comparable to that of PVC/DOP, indicating that the environmentally friendly PBM can be used as an alternative plasticizer to remove the potential health risks from migrating phthalates during applications.

Controlling the morphology of calcium sulfate hemihydrate using aluminum chloride as a habit modifier

The morphology and aspect ratio of calcium sulfate hemihydrate (HH) are successfully controlled using AlCl3 as a morphology modifier in the hydrothermal synthesis process. As the concentration of AlCl3 is increased from 0 to 7.5 × 10−2 mol L−1, the crystal length decreases from 130 μm to 0.1–0.3 μm and the corresponding aspect ratio declined dramatically from 150–240 to 1–2, and the crystal morphology gradually changes from whiskers to rods, and even irregular nanogranules. The preferential adsorption of Al3+ on the side facets of HH would lower the surface energy and inhibit the elongation along these facets. The doping of Al3+ in the HH would destroy the main chain of HH and inhibit the elongation along the [001] direction. The two facts contribute to the morphology control. This work exhibits an efficient method to control the morphology of HH over a large range of size by simply adjusting the concentration of AlCl3.

Calcium sulfate hemihydrate whisker reinforced polyvinyl alcohol with improved shape memory effect

A new shape memory polymer is synthesized by introducing calcium sulfate hemihydrate whiskers (HHW) to reinforce polyvinyl alcohol (PVA). The tensile strength of the composite is increased by 57%, and the storage modulus reaches 22.24 GPa.

A type of thiophene-bridged silica aerogel with a high adsorption capacity for organic solvents and oil pollutants

A type of thiophene-bridged silica aerogel was prepared from tetraethyl orthosilicate (TEOS) and 2,5-divinyltrimethoxysilanethiophene (DVTHP) through a facile sol–gel reaction and ambient pressure drying process. DVTHP was synthesized from vinyl trimethoxysilane and 2,5-dibromothiophene through the Heck reaction. FTIR and solid-state 1H CP/MAS NMR indicated that the thiophene units had been successfully introduced into the silica aerogel network. SEM showed a co-continuous porous structure and the Brunauer–Emmett–Teller (BET) measurements showed a mesoporous structure that had a high surface area of 834 m2 g−1, an average pore size of 17.84 nm and a large pore volume of 3.72 cm3 g−1. This thiophene-bridged silica aerogel had superhydrophobicity with a water contact angle (CA) exceeding 174° and a sliding angle of less than 3°. The silica aerogel had better selectivities for less polar or non-polar solvents than for polar solvents. The introduction of the thiophene unit could improve the adsorption properties. The adsorption capacities for n-hexane and gutter oil were calculated as 17 g g−1 and 16 g g−1, respectively. Moreover, the samples exhibited good recyclability for organic solvents even after recycling 10 times in adsorption/desorption tests and the adsorption capacities were nearly unchanged from the maximum uptake capacities. The results indicated that these materials could be flexibly utilized as adsorbent materials to selectively adsorb organic solvents for wastewater treatment.