Barrier Properties Of Composites Research Articles

Investigation on improvement of thermal, mechanical, and barrier properties of lignin/poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) using inorganic nanoparticles as fillers

AbstractIn this study, four typical biocomposites from lignin blended with poly‐3‐hydroxybutyrate‐3‐hydroxyhexanoate (PHBH) using inorganic nanoparticles (INPs) (SiO2, MMT, CaCO3, and BN) as fillers were evaluated, which enhanced the thermal, mechanical, and barrier properties of composites. The results revealed that the selection of suitable INPs doped into the lignin/PHBH (L/P) composites was an important approach to achieve available function. MMT/L/P nanocomposites were significantly higher than those of untreated L/P composites in thermal stability (Tmax exceed 10%) and barrier properties (water vapor and oxygen resistance increased by 48% and 46%), and BN particles increased the initial thermal decomposition temperature by 8%. The elongation at break of CaCO3/L/P and BN/L/P composites were increased by 344% and 319%, while SiO2/L/P composites had the best tensile strength (18.8 MPa). Besides, the INPs/L/P nanocomposites in this paper exhibited excellent ultraviolet (UV) resistance and might become potential anti‐UV packaging materials for grease foods.

Natural rubber biocomposites containing corn, barley and wheat straw

The development of high-performance materials made from available and cheap natural resources is increasing worldwide. A new solution – composites of natural rubber, containing barley, corn and wheat straw as biofillers, was reported and researched. The latest developments and trend's exams of the elastomers filled with cereal straw represent a scientific and technological innovation. The use of straw as a filler for elastomer composites bradens the range of functional properties and reduces the costs of production. The biocomposites are more ecofriendly and give the opportunity to increase the possibility of straw management which is a problematic agricultural waste. The rubber mixtures containing lignocellulosic materials demonstrate a favorable characteristic kinetics of crosslinking. The addition of filler, in an appropriate amount, modified natural rubber vulcanizates, improving mechanical and barrier properties of composites and the ability to damp under the influence of compression stress. Dynamic mechanical analysis showed change in the G′ values of the vulcanizates upon addition of straw. That indicates the presence of strongly developed network of fillers into polymer matrix which ensure of reinforcing character. The negative impact of natural fillers on resistance to thermo-oxidative aging was not observed.

The influence of platelet disorientation on the barrier properties of composites: a numerical study

Direct finite element calculations are carried out to study the relationship between the platelet orientational distribution and the overall effective barrier properties (gas permeability) of mineral filled composites. We consider multi-inclusion computer models with microstructures representative of the dilute, semi-dilute and concentration regimes. In the dilute regime, our numerical predictions validate the results of multiple scattering expansion theory. For the semi-dilute and concentration regimes representative of most real composites, we present numerical estimates quantifying the difference between the barrier properties of composites with fully aligned and randomly oriented platelets. Our numerical results can also be used to quantify the effect of the geometric factor on the gas barrier properties of polymer–mineral hybrid nanocomposites.