A Review on the Effect of Various Chemical Treatments on the Mechanical Properties of Renewable Fiber-Reinforced Composites

Table 3

Effect of acetylation treatment on various biofibers.

S. no.	Fibers used	Type of chemical treatment	Effects	Ref.
1	Coir/oil palm	Acetylation treatment	A bigger increase in tensile strength, flexural strength, Young’s modulus, and impact strength by performing acetylation treatment compared to silane treatment.	[140]
2	Flax	Acetylation treatment	An enhancement in tensile and flexural strength by 35%.	[141]
3	Abaca	Acetylation treatment	The treatment possessed higher tensile strength, Young’s modulus, and impact strength by 81, 70, and 8%, respectively.	[133]
4	Oil palm	Acetylation treatment	The treatment has high strain value which resulted in enhanced elastic and impact property.	[100]
5	Green flax	Acetylation treatment	At 65% of relative humidity, decrease in the moisture absorption. An increase in thermal stability with increase in degree of acetylation. About 25% improvement in strength properties was observed compared to untreated composites.	[139]
6	Flax	Acetylation treatment	At 18% of acetylation, concentration of flax fiber exhibited better tensile strength and thermal stability by 25% and 50%, respectively. However, the addition of maleic anhydride resulted in increase in mechanical properties by 20–35%.	[139]
7	Sisal	Acetylation treatment	Improvement in tensile strength and shear strength by 14.08% and 435%, respectively. The acetic acid treatment followed by ethyl acetate with H2SO4 resulted in high levels of cellulose swelling or loosened cell wall structure.	[104]
8	Sisal	Acetylation treatment	A decrease in dielectric constant with increasing frequency.	[105]
9	Banana	Acetylation treatment	The treated fiber has high fibrillation and is more rougher resulting in better tensile properties than mercerization treatment.	[109]
10	Grewia serrulata bast	Acetylation treatment	The treated fiber has better dimensional stability and more moisture resistance. However, high degree of ultraviolent energy can degrade the composite.	[142]
11	Phosphate bonded composite	Acetylation treatment	The treated fiber reduces water absorption and hence improves dimensional stability, tensile strength, and stiffness. However, this treatment reduces the impact strength as compared to other chemical treatments.	[143]