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Ultra-high molecular weight polyethylene (UHMWPE)/epoxy composites with excellent adhesive properties were prepared by forming an interface membrane on the UHMWPE fiber surface. The interface membrane of the UHMWPE fiber and epoxy resin was polymerized by an aldol condensation between polyvinyl alcohol (PVA) and glutaraldehyde. Different surface treatment methods of UHMWPE fibers were optimized and the two-step PVA-glutaraldehyde condensation (Corona-PG-2S) method is the best. The interfacial adhesion between UHMWPE fiber and epoxy resin was enhanced, and the adhesive properties of the composite were improved. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrum (EDS) results of the fiber treated by Corona-PG-2S shows that the surface oxygen content was up to 25.0 wt %, with an increase of 17.3 wt % compared with the surface oxygen content of unmodified UHMWPE fiber, which indicated that the surface polarity was greatly enhanced. The adhesive properties were improved by improving the polarity of the surface. The peel strength, ultimate cohesive force, tensile strength and flexural strength of the composite treated by Corona-PG-2S were greatly increased to 262.8%, 166.9%, 139.7%, 200.6% compared with those of unmodified samples. The composite prepared by Corona-PG-2S had excellent adhesive properties, demonstrating that the Corona-PG-2S method plays a major role in significantly improving the composite adhesive properties.

Polyvinyl chloride (PVC) biofilm carrier is used as a carrier for bacterial adsorption in wastewater treatment. The hydrophilicity and electrophilicity of its surface play an important role in the adsorption of bacteria. The PVC biofilm carrier was prepared by extruder, and its surface properties were investigated. In order to improve the hydrophilicity and electrophilic properties of the PVC biofilm carrier, polyvinyl alcohol (PVA) and cationic polyacrylamide (cPAM) were incorporated into polyvinyl chloride (PVC) by blending. Besides, the surface area of the PVC biofilm carrier was increased by azodicarbonamide modified with 10% by weight of zinc oxide (mAC). The surface contact angle of PVC applied by PVA and cPAM at 5 wt %, 15 wt % was 81.6°, which was 18.0% lower than pure PVC. It shows the significant improvement of the hydrophilicity of PVC. The zeta potential of pure PVC was −9.59 mV, while the modified PVC was 14.6 mV, which proves that the surface charge of PVC changed from negative to positive. Positive charge is more conducive to the adsorption of bacteria. It is obvious from the scanning electron microscope (SEM) images that holes appeared on the surface of the PVC biofilm carrier after adding mAC, which indicates the increase of PVC surface area.

Functional biocomposites are elaborated by melt-blending plasticized starch with halloysite nanotubes for drug-release applications. Halloysite nanotubes are used as nanoscale containers for vanillin storage. The ATR-IR results showed that vanillin is successfully loaded into halloysite nanotubes. The drug-loading efficiency is approximately 8 wt%, as shown by TGA and UV-VIS spectrometry. The effects of the surrounding environment and the matrix type on vanillin release kinetics and drug-release mechanisms are carefully evaluated. A relationship between the vanillin release kinetics and plasticizer type is observed. The vanillin release mechanisms are studied by fitting experimental data to three different model equations. Best fit is obtained with an anomalous law (non-Fickian). Finally, the uniaxial tensile test shows that incorporation of vanillin does not significantly affect the tensile properties. The TGA results show a slight decrease in the thermal stability of the biocomposites after the addition of vanillin. This paper presents a simple strategy to prepare starch-based films with high value with, for example, antimicrobial and/or flavor release properties, which could have strong potential for several applications, such as active and renewable packaging or even biomedical materials.

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