Swaminathan Sivaram

Swaminathan Sivaram
Indian Institute of Science Education and Research Pune | IISER

M.Sc., Ph.D ( Purdue )

About

290
Publications
23,968
Reads
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6,248
Citations
Additional affiliations
August 2016 - present
Indian Institute of Science Education and Research Pune
Position
  • Honorary Professor and INSA Senior Scientist
January 2016 - July 2016
National Chemical Laboratory
Position
  • Senior Scientist, Indian National Science Academy
January 2011 - December 2015
National Chemical Laboratory
Position
  • CSIR Bhatnagar Fellow
Education
September 1967 - September 1971
Purdue University West Lafayette
Field of study
  • Chemistry
July 1965 - June 1967

Publications

Publications (290)
Preprint
The most abundant biopolymer in nature, lignocellulosic biomass, is often disregarded as agricultural waste, contributing to environmental pollution. Several reports have demonstrated their utilization by generating nanocellulosic materials using multistep harsh treatments involving H2SO4 and NaOH. However, these processes do not reduce the waste g...
Preprint
One approach to mitigate the crisis of plastic waste is “chemical upcycling”, in which waste plastic is converted into products with higher economic value. Towards this goal, several metal-catalyzed post-functionalization of polymers have been reported, with variable success, mostly on account of lack of selectivity, use of harsh reaction condition...
Article
Transitioning from the fossil fuel era to a sustainable future requires increasing adoption of high-performing renewable materials in industrial applications. Natural polymers derived from lignocellulosic materials are often considered more...
Article
Full-text available
Well-defined six-arm star-branched bio-degradable block copolymers of l-lactide and ε-caprolactone were prepared using controlled ring-opening polymerization and a sequential monomer addition method using dipentaerythritol as the initiator core and organocatalysts at low temperatures in solution. Sequence of enchainment was changed by reversing the...
Article
Full-text available
Herein, we report various physico-chemical approaches to probe the nature of the interface between few layers graphene (FLG) and carboxylated nitrile rubber (XNBR) nanocomposites prepared through efficient blending of XNBR latex with an aqueous dispersion of FLG. The extent of physical interaction between FLG and XNBR was investigated using Lorentz...
Chapter
Controlled ring-opening polymerization (ROP) of cyclic mono and diesters provides an access to a wide range of aliphatic polyesters with a diversity of chemical and physical properties. Under optimum conditions, ROPs produce polymers with predictable and high molecular weight, narrow molecular weight distribution and controlled chain end functional...
Article
Ultrahigh molecular weight polyethylene (UHMWPE) belongs to an emerging class of high-performance specialty polymers with a unique set of properties and applications. The field has witnessed many scientific and technological advances in recent years. However, synthesis of UHMWPE is not a trivial exercise and presents several challenges. This review...
Article
Full-text available
We provide a critical perspective of the burgeoning literature on microporous polymers prepared using thermal rearrangement (TR) processes based on the learning derived from analogous chemistry involving small‐molecular‐weight compounds. TR polymers have shown interesting permeability–selectivity relationships in gas separation and, thus, have gene...
Patent
The present invention relates to a novel process for the preparation of a linear monomer alkyl lactyl lactate by a simple esterification reaction of acid with ester in presence of suitable catalysts or reagents . The present invention further relates to a process for the preparation of poly acid from alkyl lactyl lactate by using suitable catalyst...
Article
Full-text available
Improvement in electrical energy storage systems is one of the most contemporary research topics of great academic and industrial interest. Rechargeable batteries appear to be one of the most viable options for humans to migrate to a low carbon intensity mobility solution. Lithium‐sulfur battery system offers a theoretical energy density that is an...
Article
Electrolytic dissociation of lithium hexafluorophosphate (LiPF 6 ) in the nonaqueous cyclic propylene carbonate (PC) has been investigated in the wide range of concentration (0.05-3.5 M) by ⁷ Li solution-state nuclear magnetic resonance (NMR) spectroscopy. Two-dimensional heteronuclear Overhauser enhancement spectroscopy NMR experiments have not on...
Article
The International Year of the Periodic Table, proclaimed by the United Nations to begin January 2019, coincides with the one hundred and fiftieth anniversary of Mendeleev’s published Periodic Table. The Periodic Table marked the coming of age of Chemistry. Mendeleev’s genius lay not in the discovery of the fact of periodicity, but in his interpreta...
Article
Full-text available
Poly(glycerol sebacate) (PGS), produced from renewable monomers such as sebacic acid and glycerol, has been explored extensively for various biomedical applications. However, relatively less attention has been paid to explore PGS as sustainable materials in applications such as elastomers and rigid plastics, primarily because of serious deficiencie...
Article
Full-text available
The success of developing graphene based biomaterials depends on its ease of synthesis, use of environmentally benign methods and low toxicity of the chemicals involved as well as biocompatibility of the final products/devices. We report, herein, a simple, scalable and safe method to produce defect free few layers graphene using naturally available...
Patent
Adhesive composition for clutch disc application comprising of epoxy resin of bisphenol A and epichlorohydrin, partially hydrogenated carboxylated nitrile butadiene rubber.
Article
We have explored two novel comonomers, namely, 4,16-dicarboxyl[2.2]paracyclophane and 5,5′,6,6′-tetraamino-3,3,3′,3′-tetramethyl-1,1′-spirobi[indane], for the synthesis of co-polybenzimidazoles (co-PBIs) with intrinsic porosity. Both these monomers possess twisted structures that can lead to “awkward” macromolecular shapes that cannot pack efficien...
Article
Fifty-four years after the Nobel Prize was awarded to Karl Ziegler and Giulio Natta for the polymerization of olefins by complex organometallic catalysts, the field continues to elicit enormous interest, both from the academia and the industry. Furthermore, this chemistry and technology occupy a high ground in the annals of 20th-century science. Th...
Article
The name of Natta is entwined inextricably with that of Ziegler, in the famous catalyst systems known by their names and used to make polyethylene and polypropylene. Unlike ethylene, which is achiral, propylene is a prochiral molecule and upon polymerization can lead to interesting stereochemical and regiochemical enchainment sequences. Natta’s pre...
Article
Full-text available
Commercially useful rubber products viz. gloves, condoms, tyres, and rubber hoses used in high temperature environments, etc., require efficient thermal conductivity, which increases the lifetime of these products. Graphene can fetch this property, if it is effectively incorporated into the rubber matrix. The great challenge in preparing graphene-r...
Article
If Wallace Carothers was the designer, Flory was the architect and builder of the ediflce of polymer science. If Carothers was the composer, Flory was the man who wrote the notes for the music. Carothers and Flory represent the quintessential qualities that are needed to make great science–intuition and rationality, experiment and theory, fiights o...
Article
Wallace Hume Carothers holds a place of pride amongst the pantheons of twentieth-century chemists who transformed our way of thinking, and brought an entirely new perspective to a branch of science. Polymer science fiourished in the years after Carothers as never before, and led to the creation of a new industry–vibrant, useful, and exciting. The g...
Conference Paper
Methyl 12-hydroxy stearate (Me 12-HS) is an AB monomer prepared by esterification of 12-hydroxy stearic acid (12-HSA), a bio-renewable material and readily available from castor seed oil. Commercial 12-HSA has mono carboxylic acids as impurities which are not desirable since they act as chain terminators. In this study an attempt was made to prepar...
Patent
Full-text available
The present invention relates to a novel process for the preparation of a linear monomer alkyl lactyl lactate by a simple esterification reaction of acid with ester in presence of suitable catalysts or reagents. The present invention further relates to a process for the preparation of poly acid from alkyl lactyl lactate by using suitable catalyst.
Article
Well-defined multiarmed star random and block copolymers of ε-caprolactone with l-lactide with controlled molecular weights, low polydispersities, and precise numbers of arms were synthesized by the ring-opening polymerization of respective cyclic ester monomers. The polymers were characterized by 1H-NMR and 13C-NMR to determine their chemical comp...
Article
Poly(l-lactide) (PLA), a biodegradable and biorenewable polymer, has many excellent properties that are equivalent to those of petroleum-derived plastics such as polystyrene, aromatic polyesters, etc. However, a major disadvantage of PLA which limits its processability is its poor melt elasticity. In this work we explore the possibility of improvin...
Conference Paper
Full-text available
In recent decades, significant research has focused on reducing fossil-fuel dependence and building a more sustainable future, specifically through the use of polymers from renewable resources. One approach toward sustainability has been to investigate feedstock’s that have short carbon cycles, such as plants, as alternatives to petroleum-based fee...
Conference Paper
Full-text available
Poly(L‐lactide)s (PLLA) and PLLA based blends as well as their copolymers are subject of significant current research interest. PLLA has attracted considerable attention as it is obtained from plant derived resources and has useful properties such as rigidity. PLLA’s find wide use in biomedical, flexible film packaging, injection molded and extrusi...
Conference Paper
Full-text available
Poly(lactic acid) (PLA) is biocompatible and biodegradable polymer derived from renewable sources and having potential properties as compared to petroleum based synthetic plastics. One of major the disadvantages of PLA is its brittleness which restrict its use in many applications. Several strategies have been tried to improve the brittleness of PL...
Conference Paper
Full-text available
Poly(L‐lactic acid)s (PLLA) in the useful molecular weight range are best synthesised by ring opening polymerization (ROP) of L‐Lactide. In spite of being the method of choice, both in the laboratory and in industrial processes, ROP has many limitations. The cyclic lactide is relatively expensive and is incompatible for copolymerization with many α...
Article
Full-text available
High molecular weight poly(l-lactic acid) has been prepared from the corresponding functionally terminated oligomers employing a polyesterification method at room temperature using diisopropylcarbodiimide and 4-(dimethylamino) pyridinium-p-toluene sulfonate. Self-condensation of hydroxyl and carboxylic acid-terminated poly(l-lactic acid) oligomers...
Patent
Full-text available
A process for the synthesis of 100% optically pure L(+)-lactide catalyzed by zinc and tin metal catalysts of less than 150 micron particle size is disclosed. The L-lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities less than 10 meq/kg.
Patent
Full-text available
The present invention provides polymer microcapsules of biocide, useful for preparing coating materials such as interior and exterior paints, which comprises of an active agent biocide and an encapsulating polymer. Microcapsules described in this invention are prepared by dispersing an organic phase containing an active agent either in dissolved st...
Patent
Full-text available
Copolyester with improved transition temperature, melting temperature and crystallinity including units derived from lactic acid and isosorbide, where the ratio of lactic acid to isosorbide ranges from 99:1 to 50:50.
Patent
Full-text available
Copolyester with improved transition temp. (Tg of 64-74°), melting temp. (Tm of 173-186°) and crystallinity (58 to 64%) comprise units derived from lactic acid and isosorbide, wherein ratio of lactic acid to isosorbide ranges from 99:1 to 50:50.
Patent
Full-text available
Copolyester with improved transition temperature (Tg), melting temperature (Tm) and crystallinity comprising units derived from lactic acid and isosorbide, wherein ratio of lactic acid to isosorbide ranges from 99:1 to 50:50.
Patent
Full-text available
A process for the synthesis of 100% optically pure L lactide catalyzed by Zn and Sn metal catalysts of <150 μm particle size is disclosed. The L- Lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities <10 mequiv./kg.
Article
Hidden talents: Chemistry in India is currently ranked as fifth in terms of worldwide research output. G. R. Desiraju et al. discuss the current state of chemistry in India and the historic, social, cultural, and economic factors that influence its growth. They also address the issue of how to unlock the true potential of chemistry in India.
Article
Verborgene Talente: Die Chemie in Indien nimmt derzeit den fünften Rang bei der Zahl der publizierten Veröffentlichungen ein. G. R. Desiraju et al. diskutieren den Zustand der indischen Chemie und die historischen, sozialen, kulturellen und ökonomischen Faktoren, die ihre Entwicklung beeinflussen. Die zentrale Frage lautet, was zu tun ist, um das r...
Patent
Full-text available
A process for the synthesis of 100% optically pure L(+) lactide catalyzed by zinc and tin metal catalysts of less than 150 micron particle size is disclosed. The L- Lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities less than 10 meq/kg.
Patent
Full-text available
A process for the synthesis of 100% optically pure L(+) lactide catalyzed by zinc and tin metal catalysts of less than 150 micron particle size is disclosed.The L-Lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities less than 10 meq/kg.
Patent
A process for the synthesis of 100% optically pure L(+) lactide catalyzed by zinc and tin metal catalysts of less than 150 micron particle size is disclosed. The L- Lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities less than 10 meq/kg.
Article
Selective anionic polymerization of 4-vinylbenzyl methacrylate at methacrylate site has been achieved using resonance stabilized anionic initiators such as 1,1-diphenylhexyllithium (DPHLi) and tritylpotassium (TritylK) in tetrahydrofuran (THF) at −78 °C. Polymerization proceeded selectively through methacrylate functionality of the monomer in a con...
Patent
Full-text available
Copolyester with improved transition temperature (Tg), melting temperature (Tm) and crystallinity comprising units derived from lactic acid and isosorbide, wherein ratio of lactic acid to isosorbide ranges from 99:1 to 50:50.
Patent
Full-text available
Copolyester with improved glass transition temperature (Tg), melting temperture (Tm) and crystallinity comprising units derived from lactic acid and isosorbide, wherein ratio of lactic acid to isosorbide ranges from 99:1 to 50:50.
Article
Ligands (C13H9)(2,6-R2C6H3NH)SiPh2 [R = iPr (2a), Me (2b)] were synthesized by single deprotonation of the amino group in 2,6-dialkylanilines with n-BuLi at −78°C followed by reaction with fluorenyl diphenyl silyl chloride [FluSi(Ph2)Cl]. Single crystal X-ray diffraction studies revealed different geometries around the nitrogen atom for the two com...
Patent
Full-text available
A process for the synthesis of 100% optically pure L lactide catalyzed by Zn and Sn metal catalysts of <150 μm particle size is disclosed. The L- Lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities <10 mequiv./kg. The title process comprises (a) charging L(+)-lactic acid in a reactor, subjecting it to...
Article
ansa-η5-Monofluorenyl cyclohexanolato zirconium complex 3 was shown to be active for the polymerization of ethylene when activated with methylaluminoxane (MAO) at 5 bar. Up to a polymerization temperature of 40 °C, 3/MAO resulted in linear poly(ethylene)s with saturated chain ends. However, at polymerization temperatures of 60, 80, and 100 °C, a mi...
Article
Addition of [1-methoxy-2 methyl-1-propenyl)-oxy] trimethylsilane (MTS) to unsymmetrical α,β-unsaturated cyclic anhydrides (namely, itaconic anhydride and citraconic anhydride) as well as symmetrical anhydrides (namely, maleic anhydride and 2,3-dimethylmaleic anhydride) was investigated. Itaconic anhydride isomerizes to citraconic anhydride in the p...
Article
Influence of polyurethane (PU) structure on the nature of PU/clay nanocomposite was studied using varying amounts of trimethylol propane (TMP) as branching agent. The effect of hydroxyl groups in the modifier of organoclays on the structure of PU/clay nanocomposites was studied. Nanocomposites were characterized using wide-angle X-ray diffraction m...
Article
The efficiency of potassium succinate-g-polypropylene (KPPSA) as compatibilizer for the dispersion of clay in a high molecular weight polypropylene during melt mixing for the preparation of nanocomposites was evaluated and compared with maleic anhydride-g-polypropylene (PPMA). Nanocomposites were prepared by direct melt mixing and by masterbatch me...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Polycarbonate (PC)/clay nanocomposites were prepared via in situ melt polycondensation using novel organoclays modified using phosphonium and imidazolium based cations. The molecular weight of the separated polymer separated from the nanocomposites reveals that phosphonium ion modified organoclays catalyze the polycondensation of bisphenol A with d...
Article
Addition of [1-methoxy-2 methyl-1-propenyl)-oxy] trimethylsilane (MTS) to unsymmetrical ,-unsaturated cyclic anhydrides (namely, itaconic anhydride and citraconic anhydride) as well as symmetrical anhydrides (namely, maleic anhydride and 2,3-dimethylmaleic anhydride) was investigated. Itaconic anhydride isomerizes to citraconic anhydride in the pre...
Article
Living anionic polymerization has been utilized to synthesize hydroxy end-functionalized PMMA macromonomers with styryl or allyl functionalities as the polymerizable end-groups. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl f...
Article
Full-text available
Living anionic polymerization has been exploited to synthesize hydroxy end-functionalized PMMA star-branched polymers. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl function have been used to cross-link ethylene glycol dimeth...
Article
Major Applications Polyurethane urea is useful in making interior automobile parts like armrests, head rests, gear shifts, knee protection pad, etc. Rigid integral PU foams are used in electronic and construction fields. Properties of Special Interest High compressive strength, less weight, good weatherability, and excellent properties of electrica...
Article
Major Applications Polyurethane flexible foams find applications in protective packaging, gaskets, textile laminates, protective cushioning in automobiles, and two component injection-grouting resins. Rigid polyurethane foams are used as thermal insulating materials in refrigerators, freezers, and water heaters. It is also used as a roof proofing m...
Article
Major Applications Polyurethane elastomers find applications in adhesives, laminates for textiles, covering of conveyor and drive belts, welded bodies, roof underlay sheeting, magnetic tape coatings, water line tubing, and ski boot manufacture. Elastomeric RIM polyurethanes are useful in making automotive parts such as bumpers and fascia. Reinforce...
Article
Major Applications The most important practical applications of polyurea elastomers are in the production of automobile parts. High-modulus RIM (reaction-injection molded) and RRIM (reinforced reaction-injection molded) polyureas are suitable for producing high-impact external body panels. It is also useful in the forming microporous films for arti...
Article
The synthesis of well-defined poly(methyl methacrylate)-block-poly(ethylene oxide) (PMMA-b-PEO) dibock copolymer through anionic polymerization using monohydroxy telechelic PMMA as macroinitiator is described. Living anionic polymerization of methyl methacrylate was performed using initiators derived from the adduct of diphenylethylene and a suitab...
Chapter
IntroductionControl of transesterification in polyester blendsMethods of analysing transreactions in polymer blendsConclusions
Article
In an effort to understand the role of molecular structure on the thermal properties of polyesters and copolyesters, the following polyesters were synthesized:  poly(1,4-cyclohexane dimethylene terephthalate) (PCT), poly(butylene-1,4-cyclohexane dicarboxylate) (PBCD), poly(1,3-cyclopentane dimethylene terephthalate) (PCPDT), and poly(butylene-1,3-c...
Article
Hydroxyl-, amine-, and lactone-end-functional poly(methyl methacrylate)s (PMMA) were prepared with controlled molecular weights and Mw/Mn = 1.06–1.19 via group transfer polymerization. This was achieved by the electrophilic termination of silyl ketene acetal ended PMMAs with benzaldehyde, N-trimethylsilyl benzaldimine, and 5,6-dihydro-2H-pyran-2-on...
Article
Kinetics of hexene-1 polymerization was investigated using [(N,N'-diiso-propylbenzene)2,3-(1,8-napthly)-1,4-diazabutadiene]/dibromonickel/methylaluminoxane catalyst. Experiments were performed at varying catalyst and monomer concentrations in the temperature range of -10 to 35 degrees C. First order time-conversion plot shows a downward curvature a...
Article
Homopolymerization of octadecene-1 at different reaction conditions has been studied. Significant chain running can be seen at higher polymerization temperatures. Interestingly, insertion of octadecene-1 into a sterically hindered nickel-cation/carbon (secondary) bond is observed. The microstructure of the polymer was established using NMR spectros...
Article
High-temperature thermoplastic-graphite composites are prepared using polyphenylene sulfide (PPS) and polyether sulfone (PES) containing natural graphite powder. All samples are prepared by high pressure compaction and heating to high temperatures. The effect of a third additional conducting component on the electrical resistance of these composite...
Article
A new reagent system consisting of NaIO4/KI/NaCl in aq AcOH has been found to be effective in iodinating a variety of activated aromatic substrates via in situ-generated iodine monochloride, to furnish iodoaromatics in excellent yields. This iodination procedure has been applied successfully for a cost-effective synthesis of 3,3'-diaminobenzidine,...
Patent
Full-text available
Copolycarbonates containing such structural units as birefrigence-reducing or “soft block”units are prepared by conducting a reaction, such as melt polymerization or equilibration, between a precursor polycarbonate and a monomer, polycarbonate oligomer or high molecular weight polycarbonate which is a source of other structural units. The crystalli...
Article
Conjugate addition of a silyl ketene acetal [Me 2 C=C (OMe)OSiMe 3 ] to a,ß-unsaturated lactones (namely, 5,6-dihydro-2 H -pyran-2-one, 2(5 H )-furanone as Michael acceptor) occurs efficiently at room temperature in the presence of a nucleophilic catalyst, tetra - n -butyl ammonium bibenzoate (TBABB), in THF as well as Lewis acid catalysts such as...
Article
Ethylene polymerizations were performed using silica-supported 2,6-bis[1-(2,6-diisopropylphenylimino) ethyl] pyridine iron(II) dichloride with methylaluminoxane (MAO) as co-catalyst. Silica was calcined at 600, 400 and 200 °C under vacuum for 8 h. The effect of calcination temperature of silica on the polymerization activity and the properties of t...
Article
The ability of polymerizing methyl vinyl ketone (MVK) in a controlled way followed by a polymer analogous Baeyer-Villiger oxidation of the ketone group in atom transfer radical polymerization (ATRP) was determined. The feasibility of polymer analogous Baeyer-Villiger oxidation of poly(methyl vinyl ketone) (PMVK) was established which confirmed that...
Article
The atom transfer radical polymerization (ATRP) of MMA was examined using 3-bromo-3-methyl-butanone-2 (MBB) as an initiator in the presence of CuBr as catalyst and 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine (BPIEP) as a tridentate N-donor ligand. The effect of various other N-donor ligands including a bisoxazoline ligand, namely, 2,6-bis(...
Article
Conference Reports: This section contains reports on topical conferences. Reports are usually written at the request of the editorial office, but unsolicited contributions are also welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E-mail to macromol@wiley-vch.de.
Chapter
Ethylene propylene copolymers and their blends exhibit diverse degradation behavior under the influence of light, heat and radiation. In spite of many papers in this area, little, if any, mechanistic data on degradation and stabilization of this important class of materials is available in the literature. The present paper reviews the published lit...
Article
A tridentate ligand, BPIEP: 2,6-bis[1-(2,6-diisopropyl phenylimino) ethyl] pyridine, having central pyridine unit and two peripheral imine coordination sites was effectively employed in controlled/“living” radical polymerization of MMA at 90°C in toluene as solvent, CuIBr as catalyst, and ethyl-2-bromoisobutyrate (EBiB) as initiator resulting in we...
Article
Full-text available
Electrophilic alkylations of phenol/2,6‐dimethylphenol were performed with vinylidene‐terminated poly(1‐hexene)s using BF3·OEt2 catalyst. Vinylidene‐terminated poly(1‐hexene)s with Mn varying from 400 to 10000 were prepared by bulk polymerization of 1‐hexene at 50 to −20 °C using Cp2ZrCl2/MAO catalysts. The phenol/2,6‐dimethylphenol‐terminated poly...
Article
The synthesis of low-molecular-weight (weight-average molecular weight < 45,000 g/mol) lactic acid polymers through the dehydropolycondensation of L-lactic acid was investigated. Polymerizations were carried out in solution with solvents (xylene, mesitylene, and decalin), without a solvent using different Lewis acid catalysts (tetraphenyl tin and t...

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