Norazwani Muhammad Zain

Characteristics of Hydrolysis Resistant Polycaprolactone/Palm Kernel Oil Based Polyol

Polycaprolactone (PCL) polyol was prepared by a ring opening polymerization of ε-caprolactone initiated by palm kernel oil (PKO) based polyol and 1,6-hexanediol to form a PCL/PKO based polyol. The properties of polyol were varied by their initiator:co-initiator weight ratio. The completion of polyol formation was characterized through Fourier Transformation Infrared (FTIR) spectroscopy. Other parameters such as acid number and hydroxyl number of polyol were also studied to monitor the progress of reaction. FTIR results showed the significant changes particularly for the OH and C=O stretching peaks.

Green Polyurethane Adhesive Bonding of Aluminum: Effect of Surface Treatments

Aluminum alloy 2024-T3 was treated by two different methods of surface treatments i.e. by alkaline etching and warm water treatment followed by silanization method in order to enhance the adhesive bonding. The effects of both the substrate surface condition and the adhesive properties on singlelap shear resistance were analysed. Three different formulation of polyurethane adhesive by varying the NCO:OH ratio which were prepared from polyol based on polycaprolactone (PCL)/palm kernel oil (PKO) with an aromatic and cycloaliphatic diisocyanate. Moreover, wettability tests were performed in order to evaluate the effect of all parameters mentioned above on the substrate/adhesive interaction. Surface treatment with warm water and ɣ-GPS gives better wettability and adhesive bonding compared to alkaline etching surface treatment.

The compatibilty of TPU and NR blends

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blends ratios were prepared via melt blending, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature on the tensile properties and swelling ratio was studied. The addition of NR and LNR into TPU produces a decrease of tensile strength. The swelling ratio increased with the increasing of NR content in the blends. The temperatures of blending also give effects to tensile properties and swelling behavior.

Influence of Isocyanate Structures on Mechanical Performance of Aluminum Bonded with Green Polyurethane Adhesive

Polyurethane (PU) adhesives were prepared from three different polyols based on polycaprolactone (PCL)/palm kernel oil (PKO) with an aromatic and cycloaliphatic diisocyanate. The adhesives were characterized through Fourier Transformer Infrared (FTIR) spectroscopy in order to ensure the formation of urethane and the completeness of polymer reaction. The effects of NCO/OH ratios and types of diisocyanate on PU adhesive strength were investigated. The adhesive strength of metal to metal bonding was determined by single lap shear joint testing. The correlation between crosslinking of PU network and adhesive strength was also studied by performing swelling tests.

Polyurethane/Clay Shape Memory Nanocomposites Based on Palm Oil Polyol

Thermoplastic polyurethane (TPU) nanocomposites were prepared using polycaprolactonediol as the soft segment, 4,4’-diphenylmethane diisocyanate as the hard segment, 1,4-butanediol and palm oil polyol. Nanoclay with certain weight percent (wt%) was reinforced as filler to improve both mechanical and shape memory behavior of the nanocomposites. Palm oil polyol was introduced in order to provide hyperbranched structure for better dispersion of filler in the matrix as well as aiding the crosslinking process. The experimental results showed that the mechanical and shape memory behavior of clay reinforced polyurethane nanocomposites were influenced by clay weight percent in the polymer matrix. TPU with 3 wt% clay showed optimum values of mechanical properties while the shape memory behavior decreases with increasing clay content.

Effects of Mixing Parameters on Tensile Strength of TPU/NR Blends

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) were prepared via melt mixing technique, at four different blending temperature at range 180°C - 210°C and mixing times of 8, 10, 12, 14 min. The effects of both mixing parameters on tensile strength of the blends were investigated. The blend of 85TPU15NR shows the maximum tensile strength at 180°C and 10 min mixing. The viscosity of the polymer blends will decrease as the temperature increased. The movements of molecules are more worthy because of the poor molecules interaction. The increasing of mixing time will increase the compatibility of the blends and also increase in mechanical properties. Mixing time and mixing temperature are important parameters in acquiring blends having optimum mechanical properties.

Effects of NR and Liquid NR Loading on Swelling Behaviour of TPU/NR Blends

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blend ratios were prepared via melt blending at 180°C and 190°C, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature swelling index was studied. The equilibrium swelling index of TPU and its blend increase with increasing of NR, because of the easiness for solvent to diffuse into the gap between rubber molecules. The temperatures of blending also give effect to swelling behavior. Swelling index of all samples was higher when mixed the blends at higher temperature.