Growing environmental concerns and regulatory pressure have necessitated the requirement for natural fiber-based composites for various applications. . This paper focuses on the performance evaluation of epoxy reinforced with Flax and flax-ramie fiber hybrid composites. The laminates were developed through the hand layup technique with Flax and Ramie fibers using epoxy resin. The prepared samples were further analyzed under various dynamic and static conditions, including Fast Fourier Transform (FFT) analysis, impact testing, water absorption testing, and density measurement. The flax-ramie hybrid composite shows dynamic and static properties, including better vibration control, impact resistance, and lower moisture absorption, compared to the flax fiber composite. With a density of 1.17 g/cm³, the absorbs more energy (10.47 J) and withstands higher impact forces (2.08 N). These characteristics make the hybrid composite more suitable for impact-prone and water-sensitive applications.

Polylactic acid (PLA) is a well-known renewable and biodegradable polymer but is still limited by its low heat distortion temperature and brittleness. In this study, a PLA/flax composite containing flax fiber strands (5 wt%) was prepared through melt-compounding process followed by gamma irradiation at doses ranging from 0 to 20 kGy in the presence of a small amount of triallyl isocyanurate (TAIC) as cross-linking agent. The gel fraction of the composite was tested, and the datum showed that the gel fraction sharply increased first, and then slightly decreased with increasing irradiation dose. Gamma irradiation induced cross-linking of the polymer to form a three-dimensional network in the PLA/flax composite system. Irradiated composite could only swell instead of dissolving completely in chloroform, and the swollen morphology correlated with irradiation dose. The thermal stability of the PLA/flax composite was characterized using thermogravimetric analysis (TGA) temperature, and dimensional stability. Overall, irradiation modification improved the thermal resistance and dimensional stability of PLA composites. The mechanical property tests of the irradiated composites revealed increased tensile and impact strengths, reduced elongation-at-break, and unchanged tensile modulus. The analysis of water absorption of the composite demonstrated that the irradiation cross-linking induced no obvious effect on water absorption. Irradiation cross-linking modification cannot change the hydrophilicity or hydrophobicity of PLA composites. Overall, these findings look promising for future use in reinforcement and improvement of the thermal resistance of PLA/flax composites.

New-edible oil genotypes of flax can have contribution in oil seed production. Powdery mildew (Oidium lini) is one of the flax diseases Isfahan region that completely infect the crop. The objective of this study was to investigate the effect of controlling the disease on seed yield and other agronomic traits of flax. In this study, 8 edible-oil genotypes along with a landrace variety of regular flax were evaluated in two adjacent experiments using randomized complete block design with 4 replications. In one of the experiment, the disease was completely controlled by spraying with Calixin in 3 times with interval of 15 days. However, in the other experiment, there was no controlling of the disease and the plants were infected in natural field conditions. The results showed that spraying with fungicide had a significant effect only on plant height (P<0.01) and 100-seed weight (P<0.05). Plant height and 100-seed weight (P<0.05). Plant height and 100-seed weight was decreased and increased, respectively due to spraying. There was no significant interaction effect between spraying and genotypes for any trait. Base upon the results of this experiment, the occurrence of powdery mildew at the final stages of growth in flax and at Isfahan climatical conditions, had no significant negative effect on agronomic traits such as seed yield.