Nondestructive testing of defects in adhesive joints

Effect of organic modification on the compatibilisation efficiency of Poly
(trimethylene terephthalate) PTT/m-LLDPE blend nanocomposites
Kapil K. Gangele 1 , S.Mohanty 2 , S.K.Nayak 2*
Laboratory for Advanced Research in Polymer Materials,
1. Central Institute of Plastics Engineering & Technology, Bhubaneswar-751024, India
2. Central Institute of Plastics Engineering & Technology, Chennai – 600 032, India
Email: drsknayak@yahoo.com
Abstract
Poly (Trimethylene Terephthalate)(PTT) and Metallocene Linear Low density Polyethylene (m-LLDPE)
Blends and its Nanocomposites were prepared using melt blending technique in a batch mixer.
Organically modified nanoclays; Cloisite 20A(C20A), Cloisite 30B(C30B) and Bentone 109(B109) have
been used as nanoscale reinforcement to prepare blend nanocomposites. The blend composition of
PTT/m-LLDPE of 70:30 has been optimized based on the mechanical performance. Further,
characterization studies such as DMA, DSC/TGA, TEM and WAXD have been investigated to evaluate
the effect of incorporation of nanoclays into the blend matrix. WAXD studies revealed a significant
increase in of d001 spacing of clay galleries in the blend nanocomposites indicating intercalated
morphology. From DSC, it was observed that Cloisite 30B with 5 wt. % shows higher crystallization
temperature as compared with PTT Virgin and other modified clay systems. Further with the increase in
the scanning rate, Crystallization temperature of PTT virgin polymer as well as Nanocomposites
decreases. TGA thermograms indicated that the thermal stability of the blend increases with the
incorporation of Cloisite 20A. DMA measurements reveal that the Cloisite 30B nanocomposite has
maximum modulus as compared to other nanocomposites. It is interpreted from DMA results that PTT/m-
LLDPE blend is immiscible blend due to observation of two peaks and shifting of Tg outward.
Nanocomposites show higher tensile strength and modulus as well as flexural strength and modulus as
compared to optimized blend. The Effect of m-LLDPE content on the mechanical properties of PTT has
also been investigated. It is found that m-LLDPE functions as impact modifier to enhance the impact
properties of neat PTT and prepare rubber-toughened blend.
Keywords-: Poly (Trimethylene Terephthalate), Polymer Blend and Nanocomposites
Introduction
Poly (Trimethylene Terephthalate) (PTT), aromatic polyester prepared by polycondensation reaction
between propane 1, 3 diol and terephthalic acid or dimethyl Terephthalate, has gained commercialization
over the last years. PTT has become a potential competitor of PET and PBT for various emerging
applications in fibers, packaging, and films and as engineering thermoplastic [16]. PTT combines the
mechanical properties of PET and processing characteristics of PBT, thus possessing the desired attributes
of thermoplastic polyester, wherein the properties such as dimensional stability, solvent and abrasion
resistance are pre-requisite. The polymer has very good tensile strength, elastic recovery and surface
properties; together with relatively low melt temperature, good chemical resistance and rapid
crystallization rate. However, certain impediments such as low toughness, low heat distortion
temperature, low viscosity, poor optical properties and pronounced low temperature brittleness have
restricted the optimum use of PTT, as engineering plastic in many applications. Several attempts have
already been made by various researchers to increase the toughness of PTT by blending it with ABS [25],
EPDM [26] and EOC [27]. In the present investigation, mechanical, thermal and morphological