Enhanced aging resistance of poly(ε-caprolactone)/brewers’ spent grain composites

Abstract

The presented paper investigated the influence of brewers’ spent grain (BSG) extrusionparameters on the photo-oxidative resistance of poly(ε-caprolactone)-based wood polymer composites.Filler samples characterized by the higher melanoidin content were more efficient in hindering of polymerdegradation, inhibiting the decomposition of the polymer amorphous phase. As a result, deteriorationof mechanical performance was limited, which was expressed by the higher values of aging factorfor samples containing BSG extruded at higher temperatures.

Modification of Polycaprolactone with Plant Extracts to Improve the Aging Resistance

“…As demonstrated by the DSC tests presented below, the degree of crystallinity of the materials remained at a similar level despite the longer aging time; however, a decrease in tensile strength and strain at the break was observed. The decrease in mechanical properties is probably related to the degradation of the amorphous phase, which is more susceptible to UV radiation [ 48 ].…”

“…The component "L" describes the lightness of the material, the component "a" describes the color in the range from green to red, and the component "b" describes the color in the range from blue to yellow. The color difference ∆E and browning index (BI) [48] were calculated according to the equations:…”

“…The component “L” describes the lightness of the material, the component “a” describes the color in the range from green to red, and the component “b” describes the color in the range from blue to yellow. The color difference ΔE and browning index (BI) [ 48 ] were calculated according to the equations: where ΔL is the difference in L between 2 samples (virgin PLA and PLA with specific extract content) while, similarly, Δa and Δb are the differences in the a and b coordinates, respectively.…”

Mater-Bi/Brewers’ Spent Grain Biocomposites—Novel Approach to Plant-Based Waste Filler Treatment by Highly Efficient Thermomechanical and Chemical Methods

“…Currently, it lacks a broader industrial use despite its high volume of production, which is almost 12 million tonnes globally [ 34 ]. Our previous works on PCL-based composites investigated their applications as fillers for polymer composites [ 35 , 36 , 37 ]. However, similar to the results of other researchers [ 38 , 39 ], insufficient interfacial compatibility between BSG and polymer matrix was noted, mainly when the unmodified filler was applied, which could limit the potential application range of composites.…”

“…However, similar to the results of other researchers [ 38 , 39 ], insufficient interfacial compatibility between BSG and polymer matrix was noted, mainly when the unmodified filler was applied, which could limit the potential application range of composites. Incorporating thermomechanical treatment improved the composites’ performance because of changes in fillers’ polarity [ 36 , 37 ], suggesting it is a promising direction.…”