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Natural fibres and biodegradable matrices are being considered nowadays as substitutes to synthetic fibre reinforced polymer composites mainly in sectors where high load carrying capacity and high strength are not prerequisites. Present study utilizes biodegradable matrix composite prepared by varying the weight of the base material (95-170 g), binder (5-10 g), and plasticizer (5-20 g) with treated areca frond fibres as reinforcement. Contents are transferred to a pneumatic press, compacted, and subjected to curing. Taguchi method with L8 orthogonal array was used to reduce the number of experiments. Specimens for the flexural tests are cut out from the prepared laminates and tests are performed using UTM. Maximum flexural strength of 16.97 MPa was obtained with a combination of base (170 g), binder (10 g), and plasticizer (5 g). Analysis of the results indicated that plasticizer has the maximum effect on flexural strength of the biodegradable composites.

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Polymers from renewable resources recently attracted research community mainly because of environmental concerns, low cost, availability and their biodegradability after usage. However, the intrinsic deficiencies of natural biopolymers, including poor mechanical properties, poor water resistance and difficult processability limit their use. The analysis presented here, is on renewable, bio-based resins for their mechanical, morphological, thermal and hydrolytic properties. The resins were prepared from starch, cellulose, lignin, chitosan, gelatin and their derivatives. All these matrices had good thermoplastic and mechanical properties. Among these blends, a representative starch-based specimen had maximum load bearing capacity 118·17 N on tensile stress of 1·97 MPa and modulus 221·36 MPa. In case of lignin, maximum load bearing capacity was 19·96 N on tensile stress of 0·44 MPa and modulus 287·11 MPa. In chitosan, maximum load bearing capacity was 74·03 N on tensile stress of 1·68 MPa and modulus 372·35 MPa. In case of gelatin, maximum load bearing capacity was 46·43 N on tensile stress of 1·22 MPa and modulus 829·75 MPa. Mechanical strength based on modulus showed: gelatin > chitosan > lignin > starch > cellulose. Thermal withstanding trend (dry heat) showed: gelatin > lignin > chitosan > cellulose > starch, whereas moist heat showed: gelatin > lignin > starch > chitosan > cellulose. Microscopic observations and biodegradability is also discussed.

Polymer composites used in outdoor applications are exposed to environmental factors such as temperature and moisture which may affect the mechanical performance of the composites. In this study, the influence of moisture absorption on the mechanical properties of basalt-aramid/epoxy hybrid interply composites were evaluated. Two different types hybrid interply composites were taken for the investigation namely (301 A/03 B/301 A) and (451 A/03B/451 A). Composites were prepared using compression molding process and cut specimens were subjected to three different ageing environments for 180 days. Selected ageing conditions are, (i) ambient temperature ageing (ii) Sub-zero temperature ageing (−10°C) and (iii) Humid temperature ageing (40°C and 60% Relative humidity). Mechanical tests of the aged composites were carried out to analyse the behaviour of the composites. Moisture uptake of the specimens follow Fick’s law of diffusion with saturation absorption of 5.44%, 3.12% and 1.80% for ambient, sub-zero and humid specimens respectively. Results revealed that (301 a/03 B/301 a) aged composites possess higher mechanical properties compared to (451 a/03 B/451 a) aged composites. Highest reduction in properties were observed in ambient aged specimens followed by humid and sub-zero specimens. Scanning electron microscopy (SEM) was employed to observe the damage modes of the fractured specimens. Matrix deterioration, micro cracks and fibre fracture were the major types of failures observed in aged laminates.