Research Topics

Original Contributions

1. Dynamics of phase separation in polymer blends

The dynamics of phase separation of the diglycidyl ether of bisphenol A (DGEBA)/SAN and DGEBA/ABS blends was investigated by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy, atomic force microscopy, and time-resolved light scattering, TRLS ( Phys Chem Chem Phys, 2015, 17, 12760-12770; RSC Adv.3 (46), 23967-23971, 2013,Soft Matter, 8, 7452-7462, 2012. Ind. Eng. Chem. Res., 2014, 53 (17), pp 6941–6950 ,Soft Matter, 2011, 7, 7248-7256. J. Phys. Chem .B., 2010, 114, 13271–13281.). The morphologies of the blends showed a wide spectrum of new structures ranging from dispersed to co-continuous type, exhibiting irregular shapes (Ind. Eng. Chem. Res., 2012, 51 (6), pp 2586–2595 ,J. Phys. Chem. B, 2010, 114 (42), pp 13271–13281).  In most cases the time-resolved light scattering results display clearly that the phase separation takes place according to a spinodal decomposition mechanism and the evolution of scattering vector qm corresponding to epoxy droplets follows a Maxwell-type relaxation equation.  However, very complex phase separation process was also seen certain blend compositions involving both nucleation and growth and spinodal decomposition. The temperature-dependent relaxation time τ obtained for these blends can be described by the Williams−Landel−Ferry equation. It demonstrates experimentally that the coarsening processes of epoxy droplets and the final morphologies obtained in these thermoplastic−epoxy systems are affected by viscoelastic behavior (Ind. Eng. Chem. Res., 2014, 53 (17), pp 6941–6950,J. Phys. Chem. B, 2009, 113, 16, Soft Matter, in Press).

2. Development of high performance polymer nanocomposites

In the area of polymer nanocomposites, we have synthesized several nanofillers and fabricated high performance nanocomposites based on PS, EVA, NR and epoxy resin. The morphology, mechanical properties, rheology and failure properties of these composites have been carefully analyzed. (COMPOS PART A APPL S 77 (2015): 164-171. RSC Adv., 2014,4, 58047-58058 , RSC Adv., 2013,3, 24634-24643 ,J. Phys. Chem. C, 113 (1), 97,2009, Composites Part A: Applied Science and Manufacturing,40, 36,2009. Ind. Eng. Chem. Res., 48 (7), pp 3410,2009. J. Phys. Chem. B.; 2008; 112(13); 4009-4015, COMPOS PART A APPL S ,40, 36,2009. Ind. Eng. Chem. Res., 48 (7), pp 3410,2009. J. Phys. Chem. B.; 2008; 112(13); 4009-4015)

3. Chemical modifications of polymers

In the area of chemical modification of polymers, we have done excellent work on the chemical modification of PP, HDPE, PEEK, natural rubber and cellulosic materials for chemical reactions at the interface during reactive processing with other polymers. The modified polymers were characterized by different techniques. (J. Mater. Chem. C, 2014, 2, 8446-8485, Soft Matter, 2013,9, 10343-10353 Carbohydrate Polymers, 71, 343,2008, COMPOS PART A APPL S , 39, 352, 2008, Biomacromolecules 7, 892, 2006; Polymer 47, 3874, 2006; Polym. Eng. Sci., 45, 1645, 2005; J. Polym. Sci.: Polym. Phys. 42, 1417, 2004; Composites Part-A 35, 489, 2004; J. Polym. Sci.: Polym. Phys. 42, 2531, 2004; Polymer 36, 4405, 1995; J. Appl. Polym. Sci., 57, 449, 1995).

4. Reactive processing of polymer blends and composites.

We have reactively compatibilised several polymer pairs such as PTT/PC, NBR/PP, PTT/EPDM, NBR/HDPE, nylon/PS, EPR/nylon etc. In the case of NBR/PP and NBR/HDPE phenolic modified and maleic modified PP and HDPE were used as compatibilisers (International Journal of Plastics Technology, 2014,1-18.New J. Chem., 2014,38, 155-162 , J. Phys. Chem. B, 113,1569,2009, Polymer 47, 3874, 2006; Rubber Chem. Technol. 78, 286, 2005; Eur. Polym. J. 41, 1410, 2005; J. Polym. Sci.: Polym. Phys 42, 1417, 2004; Polym. Plast. Technol. Eng. , 34, 581, 1995; Polymer 37, 5421, 1996; J. Polym.Sci.: Polym. Phys. 35, 2309, 1997). The compatibilisation reactions were performed in the melt stage at high temperature in Haake or twin screw extruder.

5. Physical compatibilisation of polymer blends

In the area of physical compatibilisation of polymer blends the we have done extensive work on the compatiblisation of PB/PS, NBR/PS, HDPE/PP, NR/PS (RSC Adv., 2014,4, 25420-25429, Journal of Materials Science, 42, 2063, 2007, Polymer 46, 9385, 2005, J. Polym. Sci., Polym. Phys 40, 755, 2002, J. Appl. Polym. Sci., 2673, 1998), NR/PMMA (Polym. Eng. Sci., 36, 151, 1996) and PS/PMMA (Polymer 33, 4260, 1992) by the addition of graft, bock and random copolymers.

6. Structure-morphology- processability relationship in polymer blends and composites

Structure-morphology- processability characteristics of a large number of polymer blends such as Sorona/EPM, epoxy based blends, PS/PB, EVA/natural rubber, NBR/PS, PP/Nylon (RSC Adv., 2014,4, 58047-58058,. J. Phys. Chem. B , in press, COMPOS PART A APPL S , 39, 64,2008, J. Polym. Sci. Polym. Phys. 44, 541, 2006; Polymer 46, 9385, 2005, Polym. Eng. Sci. 45, 1645, 2005, Polymer 45, 4925, 2004, J. Appl. Polym. Sci., 49, 901, 1993; Kaut. Gummi. Kunst., 47, 108, 1994) have been analyzed.

7. Development of fiber reinforced green polymer composites

Cost effective and eco-friendly composite materials have been developed from cellulose fibers and thermoplastics (Industrial Crops and Products, 56,2014, Fibers and Polymers, 2014,15(1), 91-100. 246–254 Composites Science and Technology 67, 453,2007, Compos. Interfaces 12, 124, 2005; J.Appl. Polym. Sci., 63, 247; 1997; J. Comp. Mater., 31, 509, 1997; J. Mater. Sci., 32, 4261, 1997), thermosets ( J. Polym. Eng. 16, 266, 1997; Eur. Polym. J. 32, 1243, 1996) and rubbers (J. Polym. Sci., 53, 583, 1995; Polym. Int. 38, 173, 1995). Fundamental investigations have been performed on fiber-matrix interface adhesion, mechanical properties and viscoelastic behavior. A new method has been proposed for the estimation of fiber-matrix interface adhesion by analyzing the kinetics of transport of solvents through the composite samples (Polymer composites 26, 136, 2005, Rubber. Chem. Technol., 68, 37, 1995).

8. Design of polymeric membranes for transport and selective separation:

In the area of diffusion and transport, Dr. Thomas has developed several cost effective and trouble free rubber membranes as well as polymer blend membranes for the transport of solvents, vapours, gases and for the selective separation of liquid mixtures (Phys Chem Chem Phys, 17(17), 11217-11228; Appl Clay Sci.123, 1-10, 2016;Industrial & Engineering Chemistry Research, 2014,53 (43), 16820-16831;J. Phys. Chem. C, 2012, 116 (37), pp 20002–20014;J. Phys. Chem. B.; 112(13); 4009,2008; Ind. Eng. Chem. Res.,47 (14),4898, 2008; Biomacromolecules , 2008, 9 (11), 2969–2979.

9. Interpenetrating polymer systems

We could do excellent work on the preparation and processing of interpenetrating polymer networks from natural rubber and PS. The cross-linked rubber was swollen in styrene first, followed by polymerization and crosslinking (Macromolecules, submitted, (Polymer international 63, no. 8 (2014): 1427-1438. Polymer 51, no. 11 (2010): 2390-2402.. Journal of Polymer Science Part B: Polymer Physics 41, no. 14 (2003): 1680-1696., J. Memb. Sci; 201, 213, 2002, Polymer 36, no. 26 (1995): 4935-4942.).

10. Recycling and reuse of waste rubbers

In the area of recycling, we have developed a cost –effective technique for the recycling of cross-linked waste rubbers (prophylactics) obtained from the latex industries ((Composites Part A: Applied Science and Manufacturing, 43, 4, 2012, 735-741,J. Mater, Sci, 38, 2469, 2003, Polymer 42, 2137, 2001, Progress Rubb. Plast. Recyl. Tech. 19, 205, 2003,J. Appl. Polym. Sci., 61, 2035, 1996).

11. Synthesis of new accelerators and their use in rubber vulcanization

A series of accelerators based on 1-phenyl-2, 4-dithiobiuret has been synthesized and their effect on vulcanization has been studies. These accelerators act as excellent binary system for the vulcanization of rubbers (Journal of Theoretical and Applied Physics: (2014),8, 141.,Eur. Polym. J. 39, 1451, 2003, Studies on novel binary accelerator system in sulfur vulcanization of natural rubber (J. Appl. Polym. Sci.90, 3173, 2003.)

12. Double networking of elastomers

The new concept of double networking of elastomers has been applied to a series of elastomers. The role of double networking on the mechanical and ageing properties have been studied (( J. Appl. Polym. Sci., 2014,132, 41292, Rubber Chemistry and Technology, 80,15,2007, J.Appl.Polym. Sci. 91, 1068, 2004).

13. Dual porous polymer scaffolds for tissue engineering

Very recently electrospinning has been made use of for the development of dual porous new bio-degradable polymer nanocomposites scaffolds for tissue engineering (ACS applied materials & interfaces 5.21 (2013): 11194-11206. RSC Adv., 2014,4, 51528-51536 Materials Letters, Volume 132, 1 October 2014, Pages 34-37 Colloids and Surfaces B: Biointerfaces, 115, 2014, 244-252.) Biodegradable polymers such as PLA, PHB and polyesters are being used for this purpose. Nanofillers such as clay, carbon nanotube are being used (submitted Polymers for Advanced Technologies)

14. Microfibrillar polymer composites

We have developed a new class of microfibrillar polymer composites from PP/PBT and nylon12/PP blends. Morphology, mechanics, crystallization, dynamic viscoelastic properties have been analyzed as a function of temperature, draw ratio and blends composition (European Polymer Journal, 2009, 45, pp 1738-1747, Journal of Polymer Research,2011, 18, 1; Journal of Reinforced Plastics and Composites,2012,31 (8), 549-56)

Contact

School of Chemical Sciences and
International and Inter
UniversityCentre for Nanoscience and Nanotechnology,
Mahatma Gandhi University
Priyadarshini Hills P. O.
Kottayam, Kerala, India-686 560

Tel: 91 - 481 - 2730003, 2731036
(Off) 91 - 481 - 2597914, 2590357
(Res) 91 - 9447223452 (Mob)
Fax: 91 - 481 - 2731002, 2731009

sabuchathukulam@yahoo.co.
uk,sabupolymer@yahoo.com
sabuthomas@mgu.ac.in
Web: www.macromol.in