Nik Noriman Zulkepli

The effect of rice straw particulate loading and polyethylene glycol as plasticizer on the properties of polylactic acid/polyhydroxybutyrate-valerate blends

In this study, polylactic acid (PLA) was blended with polyhydroxybutyrate-valerate (PHBV) with different ratios of rice straw (RS) particulate content and polyethylene glycol (PEG) which acted as a plasticizer. The tensile, thermal and water absorption properties were investigated. The tensile strength and elongation at break, Eb, decreased with increasing RS particulate. The poor adhesion between RS particulate and PLA/PHBV blends was proven through scanning electron microscopy. Besides, the reaction scheme between RS particulate also has been proposed. Increased RS particulate loading and PEG presence also reduced the crystallinity of the blends. Thermal stability of the composites also decreased with the addition of RS particulate and PEG into the blends. The presence of RS particulate increased the water absorption, whereas the addition of PEG reduced water uptake due to its amphiphilic behavior. The mechanism of the effect of water absorption on PLA/PHBV blends and RS particulate was also proposed.

Thermal degradation of high-density polyethylene/soya spent powder blends

Abstract This study investigates the properties of high-density polyethylene (HDPE) with different soya spent powder (SSP) blend contents upon oven aging. The aged properties of the HDPE/SSP blends were studied by using tensile test, thermogravimetric analysis, differential scanning calorimetry and Fourier transform infrared analysis. The tensile strength and elongation at break (Eb) decreased inversely proportional to SSP content and aging period. The thermal stability of the blends was significantly reduced after 21 days of aging. After aging, the melting temperature and crystallinity of the blends decreased with increasing aging period. These results revealed that samples with higher SSP content are more brittle upon oven aging.

The Properties of Linear Low Density Polyethylene/Cyperus Odoratus (LLDPE/CY) Blends: Effect of Sodium Hydroxide

The purpose of this study was to determine the effect of treated Cyperus Odoratus (CY) with sodium hydroxide (NaOH) on the properties of biodegradable plastics made from linear low density polyethylene (LLDPE)/CY blends. Alkali treatments for natural fibers can increased adhesion between the hydrophilic fibers and hydrophobic matric. After CY was treated with 5% NaOH solution, it can be seen that the tensile strength and Young’s modulus of the LLDPE/CY blends significantly increased. Therefore, alkali treatments can be considered in modifying the properties of natural fibers.

Thermal Properties of Different Recycled Acrylonitrile-Butadiene Rubber Glove (NBRr) Size and its Blend Ratios on SBR/NBRr Blends

The effects of SBR/NBRr blends on thermal properties of such thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results showed that by incorporating the smallest size NBRr provided more surface area to interact with SBR polymers thus increased the level of crosslink. TG thermograms shown by incorporating the smallest size NBRr in all ratios exhibit better thermal stability compared to large size NBRr. Due to many crosslinks formed with the incorporation of S1, hence at the end stage of degradation there were more cyclic and aromatic carbon formed during the rearrangement of the existing char. SBR/NBRr R05 with small particle sizes S3 and S2 showed similar crystallization temperature (Tc) at 37.1 °C. However by using S1, there was a conversion of Tc to heat capacity transition from high to low energy level at temperature 37.3 °C. Smaller size of NBRr showed better dispersion with SBR matrix hence the chances of crosslink form between SBR and NBRr is higher compared to using large size of NBRr.

Preparation of Cyclopentyl Trisilanol Silsesquioxanes - Modified Natural Rubber (CpSSQ(OH)3 ENR-50) Composite Hybrid in the Presence of HCL Acid

A composite comprising cyclopentyl trisilanol silsesquioxanes (CpSSQ(OH)3) and 50% epoxidized natural rubber (ENR-50) was prepared at reflux temperature employed hydrochloric acid (HCl) as catalyst. HCl was found to be an effective catalyst to promote ring opening reaction of ENR-50 and tailored CpSSQ(OH)3 to the ENR-50 polymer chains via chemical reaction. FTIR spectroscopy reveals a hydroxyl stretching indicating the occurrence of epoxide ring opening reaction. 1H NMR analysis further proved the incorporation of CpSSQ(OH)3 into ENR-50 polymer chains via shiftment of proton chemical shift and addition in the proton integrals. Si 29NMR analysis evidence the Si-O-C bond through a chemical shift of silanol group from CpSSQ(OH)3.

Characterization of Nanocrystalline Cellulose Isolated from Empty Fruit Bunch Using Acid Hydrolysis

In recent years, there has been a great interest in the production of nanocrystalline cellulose (NCC) due to its excellent properties. In this study, empty fruit bunch (EFB) was used as the material for the production of NCC due to its high cellulose content, inexpensive and readily-available source. NCC was prepared using acid hydrolysis at 62% for 1 hours. The morphology of NCC was determined by Field Emission Scanning Electron Microscopy (FESEM). The size of NCC was less than 50 nm in width. The obtained NCC was also characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). FTIR spectra analysis showed that hemicellulose and lignin were mostly removed from the EFB after bleaching and alkaline pre-treatment. XRD diffractograms revealed that EFB nanocellulose showed a crystallinity improvement of 24.3% compared to raw EFB cellulose.

Effect of Alkaline Treatment on Sawdust Reinforced High Density Polyethylene Composite under Wide Strain Rate

In this study, the alkali treatment of sawdust using different concentration of sodium hydroxide (NaOH) is performed. The purpose of this treatment is to improve the filler-matrix compatibility, thus, enhance the properties of tested specimens under various strain rate condition. The outcome shows the alkali treated sawdust did improve its surface roughness through reduction of sawdust diameter. With this increasing of surface roughness, it will enhance the compatibility between sawdust filler and HDPE matrix. For comparison purpose, the treated and untreated sawdust filler were reinforce in High Density Polyethylene (HDPE) matrix and have been test under static and dynamic loading using Universal Testing Machine (UTM) and Split Hopkinson Pressure Bar (SHPB) apparatus. The results indicate that the stiffness and compression strength properties were improved on treated sawdust composites for both static and dynamic loading compare to untreated sawdust composites.

Properties of Natural Rubber/Styrene Butadiene Rubber/Recycled Nitrile Glove (NR/SBR/rNBRg) Blends: The Effects of Recycled Nitrile Glove (rNBRg) Particle Sizes

The effects of different particle sizes of recycled nitrile glove (rNBRg) on curing characteristics and physical properties of natural rubber/styrene butadiene rubber/recycled nitrile glove (NR/SBR/rNBRg) blends were investigated. The particle sizes of rNBRg were differentiated by the method of sizing. S1 was obtained by cutting the rNBRg into smaller sheets; S2 was obtained by passing rNBRg through 2 rolls mill for 10 times; and S3 was obtained by passing rNBRg through 2 rolls mill for 10 times and then mechanically grinded. NR/SBR/rNBRg blends were prepared at 50/30/20 composition using two roll mill at room temperature, with different particle sizes, rNBRg (S1), rNBRg (S2) and rNBRg (S3). Curing characteristics (scorch time, cure time, minimum torque and maximum torque), tensile properties and physical properties (crosslink density, resilience and hardness) of the blends were investigated. Results indicated that scorch time, cure time and minimum torque decreased as the rNBRg particle size decreased, while maximum torque and crosslink density increased. Tensile strength of the blends decreased as the rNBRg particle size reduced, which explained the formation of holes on the surfaces of tensile fracture, observed by scanning electron microscope. The rigidity of NR/SBR/rNBRg blends increased when smaller rNBRg particles were used, which explained the increased in hardness and decreased in resilience of the blends.

The Effects of Different Fillers on Mechanical and Morphological Properties of SBR/CRr Blends

This research deals with the effects of different fillers of styrene butadiene rubber/recycled chloroprene rubber/carbon black (SBR/CRr/CB) blends and styrene butadiene rubber/recycled chloroprene rubber/calcium carbonate (SBR/CRr/CaCO3) blends on mechanical and morphological properties. The range size of CRr used in this study was 181 – 549 μm. Both SBR/CRr/CB blends and SBR/CRr/CaCO3 were prepared using a two roll mill at room temperature with blend ratios 95/5, 85/15, 75/25, 65/35 and 50/50. It can be observed that, tensile strength, Eb and rebound resilience of SBR/CRr/CB blends and SBR/CRr/CaCO3 blends decreased with increasing CRr content in both blends. However, M100 increased with increasing CRr content in both blends. The scanning electron microscopy (SEM) of the tensile fractured surface of SBR/CRr/CB blends illustrates better adhesion between CB and SBR matrix compared to SBR/CRr/CaCO3 blends at all blend ratios.Keywords: styrene butadiene rubber, recycled chloroprene rubber, mechanical properties, SEM

The Study of Mechanical Properties and Morphology of Recycled Nitrile Glove Filled Epoxidized Natural Rubber Compounds (NBRr/ENR25)

The effects of mechanical properties (tensile properties and resilience test) and morphology of recycled nitrile glove (NBRr) filled epoxidized natural rubbers (ENR25) were examined. Two different size ranges of NBRr particles, i.e., S1 (250μm-500μm) and S2(2cm-5cm) were used in this study. The NBRr/ENR25 compounds with five different compositions of NBRr (5, 15, 25, 35 and 50 phr) were prepared using a two roll-mill at room temperature. The result indicated that the tensile properties such as tensile strength and elongation at break decreased as the ratio of NBRr increased. Meanwhile stress at 100% elongation show an increasing trend with the addition of recycled nitrile glove in ENR25. The resilience properties of NBRr/ENR25 compounds decreased when NBRr loading increased. The scanning electron microscopy studies showed that the fine size, S1 of NBRr particles in NBRr/ENR25 compounds illustrated a better NBRr-ENR25 matrix interaction compared with coarse size, S2 of NBRr particles. The results overall indicated that the NBRr/ENR25 with fine size, S1 of NBRrparticles show better mechanical properties (tensile properties and resilience properties) and morphology compared to coarse size, S2 of NBRr particles.