In this present work, the study of mechanical and micro-structural effect on alkaline treated sponge gourd fibre epoxy composite has been investigated experimentally. Composite laminates are fabricated by hand lay-up technique. Scanning Electro Microscope analysis on the composite materials is performed. A group of neat epoxy samples is fabricated for comparison purpose. Samples are analysed for their mechanical properties to establish an alkaline effect on sponge gourd. Indeed, a maximum value of strength and strain is observed over 20% filler loading for 24 hrs treated fibre composite.
During the last decade, natural fibre reinforced polymeric composites which substitute glass reinforcement, have witnessed considerable growth. This is attributed to their unique properties. These materials have the potential advantages of weight-saving (light material), lower raw material price from natural origin, and “thermal recycling” or the ecological advantages of using resources which are renewable. Due to the importance of natural fibre reinforced composite many non-structural components for the automotive and other sectors are now made from natural fibre composite materials [
that can extend the application of natural-fibre composites is the improvement of long-term performance including improved resistance to ultraviolet radiation and creep. Overall, natural-fibre composites are seen as potential materials for many engineering applications. However, there are still important issues that limit their future use, including long-term performance and the ability to be able to predict performance during service. Saheb et al. report that fracture mechanics can give great insight into the physical effects occurring within these composites which enable the production of natural-fibre composites with improved properties [
The sponge gourd fruit is a cylindrical, smooth and dehiscent capsule, 20 - 50 cm long by 6 - 10 cm broad, which has a characteristic fibrous mesocarp. However, the seeds are numerous, dull black, elliptic-ovoid 10 - 12 mm long by 6 - 8 mm broad. It is best grown with a trellis support, requires lots of heat and lots of water to thrive [
1) Sponge Gourd
2) Epoxy (LY 556) and Hardener (HY 951)
3) Sodium Hydroxide
4) Distilled water
5) 88 Universal Mold Release Wax
6) Acetic Acid
The equipment use was:
1) Digital weighing balance (Pocket Scale, Black AWS-100 g)
2) Steel mould (dumb-bell and sheet shape)
3) mm sieve, (YS-C-638)
4) Beaker and measuring cylinder (200 and 100 mils respectively)
Raw sponge gourd fibre was cut opened lengthwise, the dried seeds shaken out and the dried fibrous sun-dried for six (6) hours. It was later cut into smaller sizes, grounded and then sieved with 1.0 mm sieve to obtain fine fibre particles (
24 hrs. Thereafter, the laminates are taken carefully without any damage. Specimens are cut for testing as per ASTM standards.
The fibres were immersed in NaOH solution with a concentration of 20% for 12 and 24 hours respectively at room temperature. After treatment, the fibres were washed with 2% acetic acid and again washed under running water then finally allowed to dry at room temperature for 2 days.
The specimens were weighed dried (Wi), immersed in 100 ml volume of methanol solvent at room temperature for 48 hrs. After this, the samples were filtered and the excess solvent was removed patted dry with a lint free cloth and then the final weight (Wf) was noted. The percent swelling was calculated using Equation (1).
The tensile strength test was conducted on a computerized universal testing machine. The tensile test was conducted in accordance with ASTM D 3039 method. The sample of 120 mm length was clamped into the two jaws of the machine. Each end of the jaws covered 30 mm of the sample. Reading of the tensile strength test instrument for Newton force and extension were initially set at zero (
Flexural strength of samples was also tested on the computerized universal testing machine. The three-point bend flexural test was conducted in accordance with ASTM D 790 method. The five (5) samples with desired dimensions and velocity of 0.2 mm/second were tested (
where, σbh = Flexural strength; b = Width of specimen (mm); F = Breaking force (Newton); h = Thickness of Specimen (mm); L = Support distance (mm).
strength respectively. However, both figures indicate a gradual increase in both tensile and flexural strength up to 20% fibre content with 20% exhibiting the highest strength for treated polymer composite improved by the sponge gourd fibre than that of the control. Furthermore, at 25% filler loading there was a decrease in strength for both tensile and flexural strength for treated and untreated polymer composite because maximum strength had been attained and further addition of fibre content disrupts the fibre-matrix adhesion due to insufficient wetting of the fibre with the matrix.
Figures 12-14 show the phase morphology of sponge gourd fibre composite with untreated and treated (12 hrs and 24 hrs) filler loading of 5%. From the micrographs, it is clearly evident that the 24 hrs treated composite gives better interfacial interaction than the untreated and treated 12 hrs composite.
The study of mechanical and micro-structural effect of alkaline treated sponge gourd (luffa ageyptiaca) fibre epoxy composite is examined as a function of fibre loading. From the results generated, it can be established that NaOH pre-treatment of sponge gourd fibre has better reinforcing properties than the untreated fibres. The treatment is observed to have improved the flexural and tensile properties i.e. tensile strength, load at break and modulus of the composite as well as decreasing the swelling behaviour of the composite. However, 20% filler loading for 24 hrs treated fibre composite gives the best reinforcing/mechanical properties compared to other composites due to the adhesion between sponge gourd fibre and the polymer matrix.
S. I.Ichetaonye,D. N.Ichetaonye,O. G.Tenebe, (2016) Study of Mechanical and Micro-Structural Effect on Alkaline Treated Sponge Gourd ( Luffa aegyptiaca ) Fibre Epoxy Composite. Modern Mechanical Engineering,06,1-9. doi: 10.4236/mme.2016.61001