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Biodegradable copolymer-based composites produced from straw fiber (SF) with hydrolyzed soybean protein isolate/urea/formaldehyde (HSPI/U/F) copolymer-based adhesive for biocomposite flowerpots (BFP) application was presented in this work, and molecular structure, morphology, biodegradability and microbial population of the resulting materials were also investigated. FTIR and SEM results indicated that the copolymer resin have been successfully prepared. The prepared BFP showed good biodegradation, and the introduction of HSPI increased the degradation rate of BFP, which was nearly 50% at 24 months. After 30 days of controlled composting, the CO2 release accumulation of BFP could reach 24 g. During the process of BFP degradation, the number of bacteria and fungi on the surface was higher than that of actinomyces, indicating the bacteria and fungi selectively accumulated on the BFP composites surface to accelerate its degradation. At the same time, nitrate ion could also be formed by nitrobacteria, which promoted plant growth. There is no doubt that the obtained biodegradable copolymer possessed great potential for BFP application.

The effects of soil burial on the biodegradation of biocomposite flower pots (BFP) made from straw fiber (SF) and hydrolyzed soy protein isolate/urea/formaldehyde (HSPI/U/F) copolymer resin were studied in detail. The microstructure, crystallinity, functional groups, mechanical, degradation and thermal property of the prepared SF with HSPI/U/F copolymer resin have been studied, and the degradation mechanism was also elucidated. XRD results showed that the bond breakage between SF and HSPI/U/F copolymer resin induced a decrease in relative degradation-resistant crystal structures. FTIR spectra showed that the methylolated HSPI units could form a cross-linking network with U/F and SF. The BFP degradation after soil burial was mainly attributed to the effects of microorganisms. The degradation products were environmentally friendly, because they were degradable and could fertilize the soil. In addition, the U/F adhesives were slightly degraded by the microorganisms due to the HSPI in the pots. The TG and DSC results showed that the molecular motion of the BFP matrix could be restricted by the degradation action and the content of HSPI, resulting in decreased crystallization enthalpy and showing good thermal property. The tensile strength of different reinforced samples was not significantly reduced in comparison to U/F resin, and still kept good mechanical performance. Thus, the prepared SF reinforced HSPI/U/F copolymer resins could have good potential for use in the field of biodegradable flower pots because of their good thermal property, mechanical property, biodegradability, and relatively low cost.

The hydrolytes soy protein isolates (HSPI)-modified urea–formaldehyde (UF) resins were synthesized via copolymerization process. The best bonding strength is 1.50 MPa and improves 51.5% compared with pure UF. In addition, the formaldehyde emission decreased. The effect of (HSPI) on the biodegradable (UF) resins was investigated. Biodegradation was evaluated by composting under controlled conditions in accordance with ISO 14855. The faster degradation rate was obtained when lower hydrolysis degree of HSPI was added into the system. Characterization of the resulting samples was performed by attenuated total reflection Fourier transform infrared spectroscopy, thermo-gravimetric analysis, XRD, scanning electron microscopy, and AFM. The results showed that no evidence of biodegradation was found for UF resins. The UF modified with lower hydrolysis degree of hydrolytes soy protein isolates (HSPI) resulted in a faster degradation rate. The HSPI in the network of modified UF degraded first, which resulted in the ...

The hydrolyzed soy protein isolate (HSPI) was used to partially substitute urea to synthesis modified urea–formaldehyde (UF) adhesives via copolymerization process, in order to reduce the dependency on petroleum-based chemicals and mitigate possible environmental pollution. The soy protein isolate (SPI), HSPI, and modified UF adhesives were characterized by attenuated total reflection Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (1H NMR), and thermo-gravimetric analysis (TGA). The bonding strength, adhesive properties, biodegradability, and micrographs of the UF and HSPI-modified UF after degradation were also measured. The results show that the SPI native structure is unfolded during the treatment with sodium hydroxide. The thermal stability of HSPI is better than SPI. HSPI can incorporate into the structure of cured UF adhesives with three different feeding methods. And the best bonding strength of modified UF adhesives is 1.31 MPa when HSPI is added at the first step. The form...

The hydrolyzed soy protein isolate (HSPI) with different hydrolysis degree was applied to modify urea-formaldehyde resins (UF) via copolymerization process. The properties of HSPI were characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and TGA. The results show that HSPI with different hydrolysis degree is obtained. 1H NMR and ATR-FTIR spectra indicate that HSPI with different hydrolysis degree can incorporate into the structure of cured and uncured UF. The UF modified with higher hydrolysis degree of HSPI possess more stable units and contribute to the lower exothermic peak temperature in DSC curves. The bonding strength of HSPI modified UF increases as the hydrolysis degree of HSPI increases at the hot-press temperature of 120°C and decreases at the hot-press temperature of 150°C. The best bonding strength is 1.53 MPa at the hot-press temperature of 135°C and improved 56.12% compared with UF. In addition, the formaldehyde emission is dramatically reduced. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41469.