Influence of Curing Systems on Mechanical, Dynamic, and Morphological Properties of Dynamically Cured Epoxidized Natural Rubber/ Copolyamide Blends

2013 ◽  
Vol 844 ◽  
pp. 81-84 ◽  
Author(s):  
Rawviyanee Romin ◽  
Charoen Nakason ◽  
Anoma Thitithammawong

Thermoplastic elastomers (TPEs) based on dynamically cured epoxidized natural rubber/copolyamide (ENR/COPA) blends were prepared. Influence of curing systems (i.e., sulphur, peroxide, mixed sulphur and peroxide and phenolic resin cured systems on mechanical, dynamic and morphological properties of the blends were investigated. It was found that the blend with phenolic cured system exhibited superior mechanical and set properties. That is higher tendency to recover to its original shape after a prolong extension. It was also found that the blend with peroxide cured system exhibited higher storage modulus and complex viscosity than those of the blends with mixed sulphur and peroxide, phenolic and sulphur cured system, respectively. Furthermore, the TPVs blend with peroxide cured system showed the smallest vulcanized rubber particles.

2012 ◽  
Vol 626 ◽  
pp. 50-53 ◽  
Author(s):  
Krisna Sasdipan ◽  
Azizon Kaesaman ◽  
Charoen Nakason

TPNRs based on blending of co-polyester (i.e., PBT/PC) and epoxidized natural rubber (ENR) with various epoxide content (i.e., 10, 20, 30, 40 and 50 mol% epoxide) were prepared by dynamic vulcanization. It was found that the co-polyester/ENR blends gave better properties (i.e., mechanical, dynamic mechanical, morphological and oil resistant properties) than that of co-polyester/unmodified NR blend. It was also found that co-polyester/ENR with 50 mol% epoxide exhibited the highest tensile strength, elongation at break, modulus at 100% elongation, hardness, storage modulus, complex viscosity and oil resistant properties but showed the lowest tension set value. This indicates the highest elasticity. Moreover, it was found that size of vulcanized rubber domains dispersed in thermoplastic matrix decreased with increasing the epoxide content in ENR molecules.


2013 ◽  
Vol 844 ◽  
pp. 89-92
Author(s):  
Boripat Sripornsawat ◽  
Azizon Kaesaman ◽  
Charoen Nakason

Maleated natural rubber (MNR) was synthesized and formulated to prepare thermoplastic natural rubber (TPNR) by blending with co-polyamide (COPA). It was found that 100% modulus, tensile strength, elongation at break, hardness and degree of swelling increased with increasing proportion of COPA. However, degree of swelling and tension set value decreased which reflects enhancing of rubber elasticity. Dynamic properties were also determined by a rotor less oscillating shear rheometer (Rheo Tech MDpt). It was found that increasing proportion of MNR caused increasing of storage modulus and complex viscosity but decreasing tan δ value. Morphological properties were also determined by SEM technique. It was found that the MNR/COPA simple blends with the proportion of rubber 40, 50 and 60 wt% exhibited the co-continuous phase structures.


2020 ◽  
Vol 990 ◽  
pp. 262-266
Author(s):  
Prathumrat Nu-Yang ◽  
Atiwat Wiriya-Amornchai ◽  
Jaehoon Yoon ◽  
Chainat Saechau ◽  
Poom Rattanamusik

Thermoplastic vulcanizates or TPVs is a type of materials exhibiting excellent properties between thermoplastic and elastomer by combining the characteristics of vulcanized rubber with the processing properties of thermoplastics. This research aims to study the effect of thermal aging on the morphology and mechanical properties of thermoplastic vulcanizates (TPVs) based on a mixture of natural rubber (NR) and polystyrene (PS). TPVs samples were prepared using the internal mixer at a mass ratio of NR/PS 70/30, 50/50, 30/70 and 0/100. Tensile properties and impact strength showed that when the amount of NR increased tends of impact strength and elongation at break increased but tends of tensile strength decreased. On the other hand, tends of tensile strength for thermal aging at 70°C for 3 days increased when the amount of PS increase. The blending ratio of NR / PS at 70/30 is the best. It gave a worthy increase from 19.94 MPa to be 25.56 MPa (28.18%).


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