Release Profile of Nitrogen During Thermal Treatment of Waste Wood Packaging Materials

Wood packaging waste with a high recycling value is one of the main components of packaging waste.However,most research has been focused on natural wood,and less is known about the recycling of wood-based panel waste commonly used in packaging.This paper examined the pyrolysis of common urea-formaldehyde(UF)resin particleboard,including the decomposition characteristics of its nitrogen-containing adhesives,the product types,and how they are generated.The samples and pyrolysis products were analyzed by infrared spectroscopy.The results showed that the UF resin was the main contributor to the release of ammonia(NH3)and hydrogen cyanide(HCN).At low temperatures,more NH3 was released than the HCN,and at high temperatures,the reverse was true.A high heating rate promoted the release of the NH_(3) and HCN.The UF resin and wood in the particleboard interacted and caused the release of the NH3 and HCN.These results provide a reference for further study of the thermochemical regeneration of wood-based packaging waste.

Alginate-based complex fibers with the Janus morphology for controlled release of co-delivered drugs

Hydrogels are soft materials consisting of a three-dimensional network of polymer chains.Over the years,hydrogels with different compositions have been developed as drug carriers for diverse biomedical applications,ranging from cancer therapy and wound care to the treatment of neurodegenerative and inflammatory diseases.Most of these carriers,however,are designed only to deliver single agents.Carriers based on hydrogels for co-delivery of multiple agents,with the release rate of each of the co-delivered agents tunable,are lacking.This study reports a one-pot method of fabricating alginate-based complex fibers with the Janus morphology,with carboxymethyl cellulose sodium functioning as a polymeric modifier of the properties of each of the fiber compartments.By using malachite green and minocycline hydrochloride as model drugs,the generated fibers demonstrate the capacity of enabling the release profile of each of the co-delivered drugs to be precisely controlled.Along with their negligible toxicity and the retention of the activity of the loaded drugs,the complex fibers reported in this study warrant further development and optimization for applications that involve co-delivery of multiple agents.

A Detailed View of PLGA-m PEG Microsphere Formation by Double Emulsion Solvent Evaporation Method

PLGA, m PEG diblock copolymer was synthesized by bulk ring-opening polymerization method. The double emulsion solvent evaporation method was used to prepare bovine serum albumin（BSA）-loaded microspheres. Optical microscopy was used to observe the whole microsphere fabrication process. It is confirmed that the proportion of inner aqueous phase is one of the most critical factors that determines the morphology of microspheres. Double emulsion droplets which have appropriate amount of inner aqueous phase can form closed and dense microspheres, while, too much inner aqueous phase will cause a collapse of the double emulsion droplets, resulting in a loss of drug. The proportion of inner aqueous phase was varied to prepare microspheres of different morphology. The results show that with increasing the amount of inner aqueous phase, a higher percent of broken microspheres and lower encapsulation efficiency appeared, and also, a more severe initial burst release and faster release rate.