Biodiesel synthesis from non-edible vegetable oil via catalytic transesterification is one of the effective ways to replace petroleum-based fuels in the area of renewable energy development and is beneficial to environmental security. Therefore, this research investigates the optimization of process parameters (temperature, methanol to oil ratio, and NaOH catalyst dose) for the conversion of biodiesel from non-edible desert date (Balanites Aegyptiaca) seed kernel oil using the Box–Behnken experimental design of response surface methodology statistical analysis. Accordingly, the optimum values of reaction conditions, namely, a temperature of 60.5 °C, methanol to oil ratio of 6.7:1, and catalyst dose of 0.79 %wt, yielded 93.16% biodiesel. Fourier transform infrared spectroscopy analysis confirmed the cracking of a single glycerol backbone from the triglycerides and the substitution by methoxyl in the presence of a NaOH catalyst. The physicochemical properties of the biodiesel were investigated and compared with standards in terms of its density, viscosity, higher heating value, acid value, saponification value, cetane number, cloud point, pour point, and flash point, and the values are within the recommended standard limits of American Standard for Testing Material (ASTM D6751) and European Committee for Standardization (EN14214). Thus, the results revealed that homogeneous base catalysis of non-edible oil under optimum reaction conditions provides high yield of biodiesel.

The need to overcome the low energy-absorbing response and low tensile strength of geopolymers and cementitious materials has motivated researchers to develop fiber-reinforced composites. Interestingly, natural cellulosic fibers provide exciting prospects for advancements in bio-based materials compared to synthetic fibers. Incorporating fibers in such binders offer a crack limiting effect by creating multiple cracks than forming one major crack, usually leading to improved toughness and tensile strength of the composites. However, their sensitivity in alkaline media and environmental fluctuations deteriorates their durability and reinforcing capacity in composites. Therefore, exploring suitable mitigation strategies for such drawbacks of natural fibers based on previous research work and figuring out the existing gaps for further developments is extremely important. In this paper, cellulosic fiber degradation in geopolymer and cement-based matrices and the respective remedial actions have been reviewed based on a comprehensive analysis of the available literature. The influence of fiber modification and matrix treatment on the durability and strength characteristics of such composites is thoroughly discussed. Finally, recommendations and suggestions for further research in the field are presented.

Bitumen performance enhancement through modification by reactive polymers gained significant attention in the road construction industry. Polymeric bitumen additives, such as polyurethane, improve bitumen properties at low and high in-service temperatures. This research aimed to increase the polymer content (polyurethane) from 3% to 5%wt of bitumen by introducing cross-linking agent, sulfur. Synthesis of polyurethane was via in situ polymerization of bis (2-hydroxyethyl) terephthalamide (BHETA) in the presence of bitumen with sulfur as a cross-linking agent. BHETA was produced from polyethylene terephthalate (PET) by an aminolysis reaction. Penetration and softening point, frequency sweep test, performance grade (PG) and multiple stress creep recovery (MSCR) were evaluated to compare base and modified bitumen. Results show that the penetration and softening point of modified binders were reduced and increased, respectively, the frequency sweep test indicated improvement in viscoelastic properties of modified bitumen, PG of base bitumen was enhanced by two grades, i.e., from 58°C to 70°C, and the nonrecoverable creep compliance was increased by 81.82% at polymer content of 4% and sulfur content of 0.2%. The FTIR spectra of modified bitumen confirmed the formation of urethane linkages. Therefore, aminolysis of waste PET and in-situ polymerization to produce polyurethane can be applied to improve the performance of bitumen at high temperatures.

In construction engineering, there is currently a strong emphasis on finding construction materials, mainly the binder which plays a crucial role, that meet multiple criteria, including sustainability, cost-effectiveness, durability, and reduced environmental impact. However, there is a growing interest in exploring alternatives to traditional binders to address the limitations associated with their production and use. One such alternative is the use of naturally occurring materials like clay. Clay deposits are abundant and widely available, making them a sustainable resource for construction applications. Moreover, clay contains significant amounts of silica and alumina, which are key components for inducing pozzolanic reactions that contribute to the strength and durability of concrete. In recent studies, nanoclays (NCs) have emerged as a promising addition to construction materials as supplementary cementitious materials. These nanoparticles possess unique properties that can enhance the performance of concrete. Nanoclays significantly improve the compressive strength, sustainability, and durability of concrete structures. The high surface area and reactivity of nanoclays facilitate better bonding between cement particles, resulting in enhanced mechanical properties. This chapter aims to discuss the state of the art on performance enhancements of building materials that employ different types of nanoclays in place of conventional binders and the future trends.