Reinforced Epoxy Composites Modified with Functionalized Graphene Oxide

The possibility of using graphene oxide as a modifying additive for polymer fiber-reinforced composites based on epoxy resin and basalt roving has been studied. The content of graphene oxide in the system has been experimentally selected, which has the best effect on the physico-mechanical properties of the obtained polymer composite material. The efficiency of the modification of the graphene oxide surface with APTES finishing additives and aminoacetic acid, which provides chemical interaction at the polymer matrix–filler interface, has been considered. The influence of graphene oxide and functionalizing additives on the polymer curing process was investigated using the thermometric method and differential scanning calorimetry.

Research on the Ecological Protection of Coal Gangue Slope Based on a Polymer Curing Agent

To improve the ecological protection of coal gangue slopes, this work developed a polymer curing agent using a pure acrylic emulsion and cement as the main raw materials. By testing the workability, waterproofing, durability, and adhesion of the curing agent with different polymer-to-cement ratios, the optimum mixing ratio of the polymer curing agent was obtained, and the protection mechanism was analysed based on the test results and by scanning electron microscopy (SEM). Then, simulated slope and practical engineering applications were carried out. The results show that pure acrylic emulsion curing agent with a polymer-to-cement ratio of 6 : 5 is most suitable for the ecological protection of coal gangue slopes. The polymer curing agent can form a network structure film layer with a good waterproofing effect on the coal gangue surface. Simultaneously, the network structure film layer can reduce the influence of weathering and leaching on the coal gangue, prevent the heavy metal elements in coal gangue from entering the surrounding soil, improve the growth environment of plants, and improve the effect of ecological restoration. This research can be applied to the ecological protection of coal gangue slopes.

Quantitative evaluation of the non-thermal effect in microwave induced polymer curing

The non-thermal effect of microwave was evaluated quantitatively by the calculation of activation energy and pre-exponential factors with an isothermal microwave.

Application of Polymer Curing Agent in Ecological Protection Engineering of Weak Rock Slopes

Under the action of water, weak rock slopes easily expand and the strength and stiffness decrease, which results in slope instability. The styrene–acrylic emulsion cement-matrix composite, a new type of polymer curing agent, was developed for the curing and treatment of weak rock slopes. The strength-reduction factor method and ANSYS finite element software were used to calculate and analyze the stability of slopes before and after protection. The stability safety factor of weak rock after protection increased by 30% from 2.0 to 2.6. In order to evaluate the performance of the polymer curing agent, the mixture test was carried out in the laboratory. It was found that the waterproofness, hydrophobicity, and microstructure of weak rock slopes with the polymer curing agent can be significantly improved. Finally, the polymer curing agent was adopted and the external-soil spray-seeding technique was used in physical engineering. From test results, it was indicated that the polymer curing agent for weak slopes is beneficial in improving the water-damage resistance of a slope surface and prevent or reduce the softening of weak rock so that plants can grow for a long time. The treatment for weak rock slopes was successfully combined with plant protection, achieving the dual effect of weak rock slope protection and ecological protection.

Secondary Fill Minimizes Gutter Size in Chimney EVAS Configurations In Vitro

Purpose: To investigate in an in vitro model if secondary endobag filling can reduce gutter size during chimney endovascular aneurysm sealing (chEVAS). Materials and Methods: Nellix EVAS systems were deployed in 2 silicone juxtarenal aneurysm models with suprarenal aortic diameters of 19 and 24 mm. Four configurations were tested: EVAS with 6-mm balloon-expandable (BE) or self-expanding (SE) chimney grafts (CGs) in the renal branches of both models. Balloons were inflated simultaneously in the CGs and main endografts during primary and secondary endobag filling and polymer curing. Computed tomography (CT) was performed immediately after the primary and secondary fills. Cross-sectional lumen areas were measured on the CT images to calculate gutter volumes and percent change. CG compression was calculated as the reduction in lumen surface area measured perpendicular to the central lumen line. The largest gutter volume and highest compression were presented per CG configuration per model. Results: Secondary endobag filling reduced the largest gutter volumes from 99.4 to 73.1 mm3 (13.2% change) and 84.2 to 72.0 mm3 (27.6% change) in the BECG configurations and from 67.2 to 44.0 mm3 (34.5% change) and 92.7 to 82.3 mm3 (11.2% change) in the SECG configurations in the 19- and 24-mm models, respectively. Secondary endobag filling increased CG compression in 6 of 8 configurations. BECG compression changed by −0.2% and 5.4% and by −1.0% and 0.4% in the 19- and 24-mm models, respectively. SECG compression changed by 10.2% and 16.0% and by 7.2% and 7.3% in the 19- and 24-mm models, respectively. Conclusion: Secondary endobag filling reduced paragraft gutters; however, this technique did not obliterate them. Increased CG compression and prolonged renal ischemia time should be considered if secondary endobag filling is used.