Photo‐fabricated unsaturated polyester resin composites reinforced by kenaf fibers, synthesis and characterization

Abstract

New bio-fiber composites (UPRC) cured by ultraviolet radiation were produced using kenaf fiber as reinforcing agent and unsaturated polyester resins as matrix in the presence of styrene and IRGACURE 1800 as photoinitiator. Unsaturated polyester resins based on palm oil were prepared from various ratios of monoglyceride (MG)/maleic anhydride (MA) by the interaction of the corresponding MG monomer, with different equivalents of MA, in the presence of 2-methylimidazole as catalyst. The various characteristics of the obtained bio-fiber composites, including mechanical, gel content, water absorption and thickness swelling test, thermal analysis, were determined and the data were discussed. Bio-fiber composite with MG: MA ratio (1 : 4 eq./eq.) showed better mechanical properties (tensile, flexural, and impact strength) than other formulations. Gel content increased as the amount of MA was increased up to the MG: MA ratio was 1 : 4 (eq./ eq.) then slightly decreased at the higher ratio formulation. Bio-fiber composite (UPRC c ) was considered the best prepared bio-fiber composite which contained higher degree double bond, cross-linking and thermal stability. Moreover, morphological study of selected examples of the formed bio-fiber composites was also carried out and showed the evidence of the enhancement of the compatibility between fiber and polymer matrix.

Fabrication and Properties of Biobased Layer-by-Layer Coated Ramie Fabric-Reinforced Unsaturated Polyester Resin Composites

“…As observed in the DTG profile, UPR/fabric composites have two thermal degradation stages. The first degradation stage belongs to the decomposition of cellulosic fibers, and the second one is attributed to the pyrolysis of unsaturated polymer resin . The T max1 and T max2 represent the temperatures for the weight loss at the first and the second maximum rates, respectively.…”

“…The gel contents of UPRs were tested by Soxhlet extraction to determine the effects of LbL modification on the crosslinking density. 41 The samples were weighed and extracted using toluene as the solvent for 24 h. The gel content was calculated by the formula: gel content% = (W 2 /W 1 ) × 100%; W 1 and W 2 represent the weight of the sample before and after extraction, respectively. From Table 1, it is clearly found that the gel content of UP-3 is lowest.…”

Free radical photopolymerization process for fiber‐reinforced polymer: Effect on the mechanical properties

“…By the way, this short curing time should also be beneficial to reduce the emission of styrene usually used as reactive diluent and which presents safety issues. However, only few works reported the use of light for such purpose . For example, ultraviolet (UV)‐curing was used to replace the thermally cured resins for repairing damaged reinforced concrete .…”

“…However, only few works reported the use of light for such purpose. [1][2][3][4][5][6][7][8][9] For example, ultraviolet (UV)-curing was used to replace the thermally cured resins for repairing damaged reinforced concrete. 3,10,11 The UV-cured fiber-reinforced polymer was also developed for pipes repairing.…”

Frontal free‐radical photopolymerization of thick samples: Applications to LED‐induced fiber‐reinforced polymers

“…15 It is thus a wellmastered technology when it comes to coatings or thin films, but it needs adjustments to be geared to the curing of thick materials. Some academic works successfully describe the manufacturing of glass-fibers reinforced polymers using UV-curing, [16][17][18] but only a few have been interested in the mechanical properties of the obtained materials and even less in a comparison with their thermal equivalents. Among them, Zhang et al 19 showed how to overcome the problem of the limited thickness of photocomposites by applying a stepwise process for the manufacturing glass fiber/acrylate composite using 3 wt % of benzyldimethylketal as photoinitiator.…”