Thermoplastic natural rubber based on polyamide-12 blended with various types of natural rubber

Abstract

Thermoplastic natural rubber (NR) of dynamically cured 60/40 NR/polyamide (PA) blends has been prepared by using three types of NR: unmodified air dried sheet NR, epoxidized NR (ENR) with 25 and 50 mol% epoxides. Plasticizer (i.e. dioctyl phthalate (DOP)) and processing oils (i.e. treated distillate aromatic extract and paraffinic oils) were incorporated in the blends. Stress relaxation, rheological, mechanical, and thermal properties of the blends were investigated. It was found that mixing torque, shear viscosity, tensile strength, and hardness of the oil-extended blends exhibited lower values compared with the blends without oil. But higher elongation was observed due to the distribution of oil into PA-12 and rubber phases. Furthermore, an increasing trend of stress relaxation behavior and rubber index was observed in the blends with DOP, which revealed an improvement in elastic properties. It was also found that the incorporation of DOP caused an enhancement in thermal behavior in terms of T 10 , T 50 , T 90 , and integral values, but a reduction in the glass transition temperature (T g ) of NR phase and crystallization temperature (T c ) of PA-12 matrix was also observed. This is attributed to the similar solubility parameter of DOP compared with the blend components. It was also found that the dynamically cured blends showed smaller rubber Downloaded from domains dispersed in PA-12 matrix. However, the addition of DOP resulted in an increase in the size of vulcanized rubber particles.

Influence of epoxidized natural rubber on the phase structure and toughening behavior of biocarbon reinforced nylon 6 biocomposites

“…The formation of ENR-g-nylon has been reported in literature to be more thermally stable than both nylon or ENR 8 and also stronger with higher ow resistance in the molten state. 27 Therefore, the presence of a more thermally stable, stronger and ow resistant material graed to nylon chains can cause a shi of the T g to a higher temperature. Nouparvar et al 8 studied the thermal properties of nylon 6 and ENR blend composites with clay and found that the formation of ENR-gnylon at the interface led to improved melting temperature of the nylon due to its higher thermal stability.…”

Effect of Plasticizers on Morphology, Mechanical Properties and Water Absorption of Wheat Gluten and Epoxidized Natural Rubber Blend

“…Furthermore during the mixing step, DOP probably migrated from protein phase to ENR phase. This is because the solubility parameters of DOP (δ = 18.28 MPa 1/2 ) [12] is very close to ENR50 (δ = 18.20 MPa 1/2 ) [13] than that 290…”

Materials for food packaging applications based on bio-based polymer nanocomposites

“…85 NR has been reported to improve and modify the mechanical properties of blends, making their use possible and feasible. Different polymer matrices including PP, 117,118 PE, 14,119 PU, 12 LDPE, 72 linear LDPE (LLDPE), 120,121 high-density PE, [122][123][124] ultra LDPE, 125 PA, 126 chitosan 127 and PLA 70 have been blended with NR. Mechanical and thermal properties of different NR polymer blends are shown in Table 3.…”