Properties of Compatible Soy Protein Isolate/Polycaprolactone Composite with Special Interface Structure

Abstract

It is important to improve the compatibility and ultimately the properties of biobased polymer materials as alternative materials for non-degradable polymer materials. In this study, polyurethane prepolymer (PUP) was synthesized from PCL diols, and the PUP with special structure was used as a compatibilizer to improve the compatibility between hydrophilic soy protein isolate (SPI) and hydrophobic PCL composites. The structure and properties of the soy protein isolatepolycaprolactone (SPI-PCL) composites were investigated. The results showed that the mechanical properties such as the tensile strength, impact strength, and bending strength of the modified composites were increased as compared to un-modified composites, respectively. Also, the SEM results showed that the interfacial adhesion between the hydrophobic PCL and hydrophilic SPI was also enhanced because of the existence of compatible PU interfacial layer in the composites. Clearly, the strong urethane linkage interaction between the PU interfacial layer and the SPI particles, and the PCL-PCL crystallinity interactions between the PU interfacial layer and PCL matrix were responsible for the improved compatibility in the SPI-PCL composites. Therefore, the addition of the PUP with the special structure improved the compatibility and the properties of the SPI-PCL composites significantly. POLYM. COMPOS., 00:000-000,

Nanoclay incorporation into soy protein/polyvinyl alcohol blends to enhance the mechanical and barrier properties

“…Of these methods, blending with other polymers with fine mechanical and water resistance properties could be regarded as the most effective and low cost method. When blending with some hydrophobic polymers, such as polylactide , polycaprolactone , poly(butylene succinate)‐co‐adipate , etc. compatibilizers were usually incorporated for the high difference of hydrophilicity.…”

Enhanced electrical and dielectric properties of plasticized soy protein bioplastics through incorporation of nanosized carbon black

“…Further, the moisture sensitivity and poor mechanical properties became the main drawbacks limiting the applications of soy protein materials. 8 Efforts have been made to improve the mechanical properties and water resistance of SPI by crosslinking, 9 surface coating, 10 blending with other polymers, such as, polycaprolactone, 11 konjac glucomannan, 12 poly (vinyl alcohol), 13,14 poly (butylene succinate) and its copolymer, 15,16 and so forth. Incorporating reinforcing agents is also a very promising path to improve the mechanical properties of soy protein based materials.…”

Evaluation of conductivity and mechanical properties of natural fiber reinforced soy‐melamine formaldehyde based green composite

“…The scope of direct use of water‐based soy milk as matrix for preparation of natural fiber based composites has already been explored through different research 4 . But poor mechanical strength and water resistance of these composites are the major draw backs to explore these materials in composite market 5 …”

“…1 Natural fiber as the reinforcement in biodegradable resin provides better physical-chemical and mechanical performances, cost effectiveness, and durability, which is reported by several researchers. [2][3][4][5] Biodegradable protein-based resins like SPI, SPC, which require a lot of processing from soy bean have been extensively explored as strong and biodegradable matrix for natural fiber composites by past researchers. 3 Still, it appears that there remains a scope for the development of a simplified process for preparation of soy resin from soy bean without going through isolation or concentration of the soy protein.…”

“…4 But poor mechanical strength and water resistance of these composites are the major draw backs to explore these materials in composite market. 5 Liu et al fabricated green composite from pineapple leaf fiber and soy plastic (soy flour blended with polyester amide) by extrusion process. Physical properties like tensile, impact and flexural strength enhanced significantly in presence of compatibilizer which helped in better connection between reinforcing fiber and matrix and stress transfer of matrix to fiber.…”