Composites science and technology

Porous materials for sound absorption

The environmental problems associated with the production, disposal and recycling of synthetic fibre based polymer composites has prompted the development of eco-friendly natural fibres. It involves use of kenaf, jute, oil palm, cotton, flax, banana, hemp, sisal and pineapple leaf fibre (PALF) for various applications such as automotive, infrastructure, biomedical, furniture, packaging etc. PALF will be important in material development for structural and non structural industrial products with other natural and synthetic fibres with different matrix. This review paper deals with the mechanical properties evaluation of PALF and several factors influencing properties such as type of variety, fibre length, matrix type, fibre orientation, voids and porosity content. Recent research in the advancement of mechanical properties of PALF as reinforcement in thermoset, thermoplastic and biodegradable resins are briefly provided. Attempts have been made to characterize PALF as a hybrid composite with other natural and synthetic fibres. Surface treatments to improve the interfacial and interphasial PALF - matrix interaction with consideration of coupling agents for mechanical strength improving requirements are discussed. Along with limitations, technical solutions to the traditional problems of natural fibre composite processing, tensile properties improvement, durability, thermal stability and interfacial incompatibility enhancement are discussed. Overall, this review article investigates highlights and identifies gaps in the earlier research work. It provides the resourceful tabulated data for continuing future research in various streams with PALF as reinforcement.

Review on mechanical properties evaluation of pineapple leaf fibre (PALF) reinforced polymer composites

The year 2020 faced unprecedented challenge for most of the global economic growth due to the outbreak of Coronavirus disease (COVID-19). Despite a downward trend performance of the Malaysian oil palm industry, particularly for the first half of 2020, the impact is less severe due to the encouraging palm oil export revenue through the National Economic Recovery Plan (PENJANA) which nurtures a notable increase in crude palm oil (CPO) price. In honouring the Malaysian pledge on forest conservation, land expansion for the oil palm cultivation remains stagnant over the years. The effort is now shifting towards enhancing the oil palm yield performance through new planting materials and good agricultural practices, coupled with systematic pest and disease management. Sustainability continues to be the key agenda of the oil palm industry, in moving forward to sustain the industry ecosystem. The industry is now open for innovative palm oil processes to comply with the dynamic and stringent food safety and quality standards and trade regulations. Owing to the distinction in food and feed applicability together with health prospects, translating the information into consumer-friendly language is becoming crucial for effective communication. Valorisation via the concept of 'waste to wealth' has compelled series of innovations in capitalising oil palm co-products for greener bioenergy and oleochemicals, and source of phytonutrients to generate higher earnings without having to heavily rely on palm oil trade as commodity. Mandatory enactment of the Malaysian Sustainable Palm Oil (MSPO) certification scheme has portrayed a success story of showing the utmost commitment towards sustainability. With persistent dedication, the oil palm industry is envisaged to be self-sustaining, amidst the never-ending challenges surrounding economy, well-being and environment.

/pdf/oil-palm-economic-performance-in-malaysia-and-r-d-progress-vv8ak180n1.pdf

Oil palm economic performance in malaysia and r&d progress in 2019

Building envelope insulation is crucial for an energy-efficient and comfortable indoor environment because the envelope accounts for 50–60% of total heat gain/loss in a building. Previous studies mostly used lifecycle cost as the criteria to select the optimum insulation materials with little or no consideration of embodied energy, emission, and summer overheating potential. This study presents a comparative analysis of building insulation materials properties (thermal, hygroscopic, acoustic, reaction to fire, environmental, and cost) and their performance in different climate zones and proposed an optimization framework. Insulation materials can be primarily categorized as conventional, state-of-the-art and sustainable. State-of-the-art insulation materials have the lowest thermal conductivity value amongst the three insulation types. However, their life cycle cost is higher compared to the other types. Sustainable insulation materials could be useful to delay and minimize indoor peak temperature and reduce overheating risk during the hot summer period. The analysis also showed that building walls with comparatively lower thermal resistance are more cost-effective for the cooling dominated region, but walls with higher thermal resistance are more cost-effective in heating-dominated regions. However, highly insulated and airtight houses may also lead to increased overheating risk and peak cooling demand during a hot summer period. In addition, hygroscopic, acoustic, and fire retardancy properties of insulation materials are critical to control indoor relative humidity in a humid region, to maintain a minimum noise level in a zone, and to reduce fire destruction. Hence, the optimization should include four criteria 1) Energy, 2) Environment, 3) Economic, and 4) Comfort.

Comparative analysis of building insulation material properties and performance

Sound absorption of extracted pineapple-leaf fibres

Oil palm empty fruit bunch fibres as sustainable acoustic absorber

Thermoplastic starch composites have attracted significant attention due to the rise of environmental pollutions induced by the use of synthetic petroleum-based polymer materials. The degradation of traditional plastics requires an unusually long time, which may lead to high cost and secondary pollution. To solve these difficulties, more petroleum-based plastics should be substituted with sustainable bio-based plastics. Renewable and natural materials that are abundant in nature are potential candidates for a wide range of polymers, which can be used to replace their synthetic counterparts. This paper focuses on some aspects of biopolymers and their classes, providing a description of starch as a main component of biopolymers, composites, and potential applications of thermoplastics starch-based in packaging application. Currently, biopolymer composites blended with other components have exhibited several enhanced qualities. The same behavior is also observed when natural fibre is incorporated with biopolymers. However, it should be noted that the degree of compatibility between starch and other biopolymers extensively varies depending on the specific biopolymer. Although their efficacy is yet to reach the level of their fossil fuel counterparts, biopolymers have made a distinguishing mark, which will continue to inspire the creation of novel substances for many years to come.

Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review.

Fatigue life characteristic of hybrid composite reinforced metal laminate is a notable investigation since this kind of material offers several superior characteristics over conventional metallic a...

Investigation on the fatigue life characteristic of kenaf/glass woven-ply reinforced metal sandwich materials

This study investigates the mechanical properties of high impact polypropylene
composite reinforced with pineapple leaf fibre from the Josapine cultivar as a function of
fibre loading. PLF was extracted by using a pineapple leaf fibre machine and then an
alkaline treatment was conducted to enhance the properties. Samples of the composite
were fabricated with 100 mm fibre length with five different fibre loadings of PLF (30,
40, 50, 60 and 70 wt%). The fabrication was made by a compression moulding technique
with unidirectional fibre orientation. Related tests such as tensile, hardness and density
tests were conducted to determine the effect of fibre loading. The experimental data
showed that the composite with the 60 wt% fibre loading offered the highest value of
tensile strength, which was about 309%, and the Young’s modulus was about 540%
compared to 0 wt% of PLF loading. Meanwhile, the hardness and density of the PLF/PP
composites showed very similar values, with small increments from 30 wt% up to 70 wt%
PLF loading compared to 0 wt% of PLF loading. The highest values are 65.38 Shore-D
and 1.002 g/cm³ respectively. The results also revealed that PLF from the Josapine
cultivar with alkaline treatment greatly influences the mechanical properties of PLF/PP
composite.

/pdf/mechanical-properties-of-polypropylene-composites-reinforced-2cbhlqgfyc.pdf

Mohd Zulkefli Selamat

Papers

Sound absorption of extracted pineapple-leaf fibres

Oil palm empty fruit bunch fibres as sustainable acoustic absorber

Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review.

Investigation on the fatigue life characteristic of kenaf/glass woven-ply reinforced metal sandwich materials

Mechanical properties of polypropylene composites reinforced with alkaline treated pineapple leaf fibre from Josapine cultivar