Table 7.
Water absorption behavior of recently developed hybrid biocomposites.
| Matrix | Fibers | Manufacturing Process | Treatment | Water Absorption | Ref. |
|---|---|---|---|---|---|
| PLA | Kenaf fiber and MMT clay | Extrude, roll mill compression molding | NaOH treatment | Adding one wt %, MMT decreased WA 1 due to the barrier effects | [261] |
| Green epoxy | Sisal/hemp | Hand lay-up and hot press | - | Higher WA of hybrid composite (12%) than the pure or non-hybrid composites (7%) | [177] |
| PLA | Aloevera fiber and MMT clay filler | Twin-screw extruder, two-roll mill, and compression molding method | NaOH treatment | Hybridization increased WA Increasing MMT content (3 wt %) maximized water-resistance of hybrid biocomposite | [262] |
| Epoxy | Luffa/coir/SiO2 nanospheres | Conventional molding Fiber loading: 40 vol % |
NaOH treatment | Decrease of WA to 0.14% by adding 3 vol % of SiO2 | [263] |
| polyester | Jute/glass Sisal/glass Sisal/jute/glass |
Hand lay-up | Treatment with succinic anhydride and phthalic anhydride | Hybridization of JF and SF with glass fiber reduced the WA content significantly | [274] |
| Epoxy resin araldite | Sisal/coir (1:1) | Cold pressing | - | WA of hybrid composites increased with an increase of fiber wt % and soaking duration | [275] |
| Epoxy Resin | pineapple/coir (1:1) | Hand lay-up | - | Coir/pineapple/coir (CPC) pattern showed the highest water resistance to PCP and P/C patterns | [276] |
| Isothalic polyester | Jute/glass | Hand lay-up | UV radiation treatment | Improvement in water/moisture absorption resistance | [29] |
| Liquid diglycidyl ether of Bisphenol-A blended with neem oil | Kenaf fiber and sea-urchin spike filler | Casting | Amino silane surface treatment | Surface-modified kenaf fiber improved water resistance The addition of neem oil into epoxy did not change WA |
[277] |
| Polypropylene | Sisal/glass | Injection molding | NaOH treatment | The addition of 10 and 20 wt % glass fibers showed improvement in water resistance | [278] |
| Epoxy resin | Hemp/jute Hemp/flax Hemp/jute /flax |
Hand lay-up compression technique | - | Hemp/jute/epoxy, hemp/jute/flax/epoxy and hemp/flax/epoxy absorbed 4.5%, 3% and 2.8% water respectively | [240] |
| Low-density polyethylene | Jute/bamboo (1:1) cellulose Untreated jute/bamboo |
Hot press | Dewaxing, alkaline treatment, and mercerization | Lower WA of treated cellulose hybrid composites (0.7%) with ten wt % fibers loading respect to untreated fiber | [279] |
| Starch-glycerol | Jute with and without epoxy resin coating (Araldite CY-230) | Wet hand lay-up and compression molding | Treatment by alkaline sodium hydroxide | A thin coating of epoxy reduced the WA significantly | [280] |
| Novolac type Phenolic formaldehyde | PALF/kenaf | Hot press | Triethoxy (ethyl) silane treatment | Treated hybrid composites revealed a reduction in WA 70P:30K ratio showed the lowest WA |
[281] |
| Unsaturated polyester (UP) blended epoxy | E-glass fiber and iron (III) oxide particles | Hand lay-up | Amino-silane (APTMS) treatment | Low WA was observed for composites consist of 5 and 10 vol % of UP into epoxy | [282] |
| Epoxy | Coir fiber with Al2O3 filler | Hand-lay-up Fiber loading: 5, 10, 15, and 20 wt % Filler loading: 10 wt % |
- | Amount of WA increased along with increasing fiber loading and decreasing epoxy loading | [283] |
| Thermoplastic SPS/agar (TPSA) | Sugar palm starch (SPS) | Hot press | - | Minimal improvement of water resistance properties | [219] |
| Epoxy LY 556 | Date Palm Leaf (DPL)/glass | Hand lay-up | Alkaline treatment | The rate of WA of the composites increased by adding more DPL fiber Maximum water uptake in 30 wt % of DPL |
[284] |
| Polypropylene | Banana/Coir | Twin-screw extruder and injection moulding Fiber loadings (CF/BF/PP): 15/5/80, 10/10/80, and 5/15/80 wt % |
- | Increase of WA with an increase of soaking time and coil wt % | [222] |
| Epoxy | Sisal/Jute | Hand lay-up Jute/sisal ratio = 1:0, 1:3, 1:1 and 0:1 |
Alkaline treatment | Fiber loading: 30 wt % Lower WA of 1:1 hybrid composite due to the better interfacial bonding of matrix/fibers |
[225] |
| Epoxy | Kenaf/Kevlar | Hand lay-up Three types of kenaf fiber: woven, UD, mat |
- | Woven and UD kenaf absorbed less water | [228] |
| Epoxy | Jute/Glass | Epoxy/jute/glass weight ratio = 69/31/0, 68/25/7, and 64/18/19 wt % | - | THE lowest WA was for hybrid composite with a 64/18/19 ratio (11.7% after 1172 h immersion in water) | [231] |
| Epoxy | Hemp/polyethylene terephthalate (PET) | Vacuum-infusion | - | WA of the hemp/PET hybrid composite was half of the woven hemp composites | [235] |
| Epoxy | Flax/Glass | Compression-molding machine Sandwich structure: outer layers of glass/epoxy and the core from Flax/Epoxy |
- | Hybrid composite of UD flax/glass/epoxy had a lower WA (4.6%) after 40 days to the carbon/epoxy and carbon/flax/epoxy composites | [180] |
| Vinyl ester | Flax/Basalt | Vacuum-infusion Fiber stacking sequence: BFFFFB |
- | Hybrid composite exhibited lower WA compared to the flax/vinyl ester composite | [285] |
| Epoxy | Sugar palm fiber (SPF)/Glass | Hand lay-up Glass fiber ratio: 30%, 50%, and 70 wt % |
Benzoylation treatment on SPF | Treated hybrid composite with 50wt % glass fiber exhibited min WA after 2h (0.16%) | [233] |
| PLA | Coir fiber (CF)/PALF | Internal mixer followed by compression molding CF:PALF ratios = 3:7, 1:1 and 7:3 |
Alkaline treatment | Fibers loading: 30 wt % C7P3 (CF:PALF = 7:3) showed the lowest WA (5.24%) after 7 days |
[238] |
| PLA-g-GMA | Agave fibers/nanoclay particles | Extrusion | Compatibilizer: glycidyl methacrylate (GMA) | Compatibilizing compensated the hydrophilic character of agave fibers and decreased the WA | [206] |
| Unsaturated polyester | Sugar palm yarn/glass | Sheet molding process and hot press | - | Increasing the glass fiber content from 30% to 50 wt % improved WA properties | [213] |
1 Water absorption.