Iranian Polymer Journal

, Volume 25, Issue 8, pp 711–723 | Cite as

Novel ternary blends of natural rubber/linear low-density polyethylene/thermoplastic starch: influence of epoxide level of epoxidized natural rubber on blend properties

  • Skulrat Pichaiyut
  • Suwaluk Wisunthorn
  • Chattrapa Thongpet
  • Charoen Nakason
Original Paper


Novel degradable materials based on ternary blends of natural rubber (NR)/linear low-density polyethylene (LLDPE)/thermoplastic starch (TPS) were prepared via simple blending technique using three different types of natural rubber (i.e., unmodified natural rubber (RSS#3) and ENR with 25 and 50 mol% epoxide). The evolution of co-continuous phase morphology was first clarified for 50/50: NR/LLDPE blend. Then, 10 wt% of TPS was added to form 50/40/10: NR/LLDPE/TPS ternary blend, where TPS was the particulate dispersed phase in the NR/LLDPE matrix. The smallest TPS particles were observed in the ENR-50/LLDPE blend. This might be attributed to the chemical interactions of polar functional groups in ENR and TPS that enhanced their interfacial adhesion. We found that ternary blend of ENR-50/LLDPE/TPS exhibited higher 100 % modulus, tensile strength, hardness, storage modulus, complex viscosity and thermal properties compared with those of ENR-25/LLDPE/TPS and RSS#3/LLDPE/TPS ternary blends. Furthermore, lower melting temperature (T m) and heat of crystallization of LLDPE (∆H) were observed in ternary blend of ENR-50/LLDPE/TPS compared to the other ternary blends. Also, neat TPS exhibited the fastest biodegradation by weight loss during burial in soil for 2 or 6 months, while the ternary blends of NR/LLDPE/TPS exhibited higher weight loss compared to the neat NR and LLDPE. The lower weight loss of the ternary blends with ENR was likely due to the stronger chemical interfacial interactions. This proved that the blend with ENR had lower biodegradability than the blend with unmodified NR.


Thermoplastic elastomer Biodegradation Ternary blends Natural rubber Thermoplastic starch Epoxidized natural rubber 



This research was supported by the Higher Education Research Promotion and National Research University Project of Thailand, Office of the Higher Education Commission, Prince of Songkla University, Contract No. SIT570565S. The author also would like to acknowledge Dr. Seppo Karilla who contributed to proof this manuscript.


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Copyright information

© Iran Polymer and Petrochemical Institute 2016

Authors and Affiliations

  1. 1.Department of Rubber Technology, Faculty of Science and Industrial TechnologyPrince of Songkla University, Surat Thani CampusSurat ThaniThailand

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