02609nas a2200337 4500008004100000022001400041245017500055210006900230260000800299300002100307490000700328520146600335653001901801653003301820653001401853653000901867653003001876653001301906653001901919653001701938653001301955653001401968100002201982700002102004700002002025700002902045700002502074700002302099700001802122856013102140 2021 eng d a8756-087900aControlling draw resonance during extrusion film casting of nanoclay filled linear low-density polyethylene: an experimental study and numerical linear stability analysis0 aControlling draw resonance during extrusion film casting of nano cJUL a87560879209784430 v373 a

Commercially important extrusion film casting (EFC) processes for manufacturing plastic films or sheets are hampered by several instabilities that severely limits their productivity. In this research we focussed on one important instability: the draw resonance that occurs during the EFC process mainly under extensional flow conditions. Draw resonance is the sustained periodic oscillations in the film dimensions, notably film width and thickness, when the process operates beyond a critical draw ratio (CDR). In this research our goal was to reduce this draw resonance instability by incorporating well dispersed nanoclay fillers in a base polymeric resin (such as a linear low density polyethylene - LLDPE) to determine how these nanocomposite (NC) formulations can prevent or reduce the draw resonance defect. EFC experiments were conducted on the base resin and on the NC formulations under non-isothermal conditions to determine the onset of the draw resonance experimentally. Conventional linear stability analysis was performed to determine the onset of the draw resonance defect numerically. Numerical predictions for the onset of draw resonance were in qualitative agreement with our experimental data. Our results showed that incorporating appropriate nanoclay concentrations in a base polymeric resin indeed enhanced the EFC process stability for those polymer formulations and thus can have important economic implications for processors.

10aDraw resonance10aextensional strain hardening10aExtrusion10aFilm10ahydrodynamic interactions10aNanoclay10aNanocomposites10aPolyethylene10aRheology10astability1 aRokade, Dhammaraj1 aChougale, Sanket1 aPatil, Prashant1 aBhattacharjee, Tanushree1 aGawande, Dnyaneshwar1 aPol, Harshawardhan1 aDhadwal, Renu uhttps://library.ncl.res.in/content/controlling-draw-resonance-during-extrusion-film-casting-nanoclay-filled-linear-low-density02655nas a2200289 4500008004100000022001400041245013800055210006900193260000800262300001200270490000700282520171900289653001902008653001402027653000902041653001702050653002402067653002002091653001202111653001002123653002102133100002202154700002002176700002302196700002302219856012302242 2023 eng d a8756-087900aRheology and processing study on controlling material and process defects in polymer melt extrusion film casting using polymer blends0 aRheology and processing study on controlling material and proces cAPR a211-2400 v393 a

The primary objective of this research paper is to control the material and process defects in polymer melt extrusion film casting (EFC) process for linear chain architecture polyethylene (PE) resins through polymer blending methodology. Extrusion film casting is a well-known industrially important manufacturing process that is used to manufacture thousands of tons of polymer/plastic films/sheets and coated products. In this research, the necking defect in an EFC process has been studied experimentally for a linear low density polyethylene (LLDPE) resin and attempts have been made to control its necking by blending in a long chain branched (LCB) low density polyethylene (LDPE) resin. The blending methodology is based on the understanding that a LDPE resin displays enhanced resistance to necking as compared to the LLDPE resin. It is found that added LDPE resin enhances necking resistance for the primary LLDPE resin. Further, as the LDPE concentration increases in the blend formulation, the necking is further reduced as compared to pure LLDPE. Analogous to past studies on EFC of linear and long chain branched architecture containing PEs, it is observed that as the LDPE is increased in the blend formulations, the formulations displayed enhanced melt elasticity and extensional strain hardening in rheological studies. It is concluded from this study that polyethylene resins having linear chain architecture can be made amenable to enhanced resistance to necking using appropriate amount of a long chain branched resins. Finally, process defects such as the draw resonance onset could be shifted to higher draw ratios as the LDPE level is increased in the LLDPE-LDPE blend formulation.

10aDraw resonance10aExtrusion10aFilm10alinear chain10along-chain branched10amelt elasticity10aNecking10aonset10astrain hardening1 aRokade, Dhammaraj1 aPatil, Prashant1 aNandimath, Sheetal1 aPol, Harshawardhan uhttps://library.ncl.res.in/content/rheology-and-processing-study-controlling-material-and-process-defects-polymer-melt02202nas a2200265 4500008004100000022001400041245011700055210006900172260000800241490000700249520127100256653001701527653003001544653002601574653002301600653002801623100002101651700001601672700003101688700002001719700001701739700002401756700002401780856013201804 2025 eng d a0947-653900aElectrochemical deconstruction of waste polyvinylidene chloride (PVDC) to value-added products in batch and flow0 aElectrochemical deconstruction of waste polyvinylidene chloride  cFEB0 v313 a

Chlorinated polymers have made enormous contributions to materials science and are commercially produced on a large scale. These chlorinated polymers could be recycled as chlorine sources to efficiently produce valuable chlorinated compounds owing to their facile release of HCl. Although the thermal stability of PVDC is low compared to PVC, this can be advantageous in terms of easy and fast dehydrochlorination. Herein, we report an efficient electrochemical chlorination using poly(vinylidene chloride) (PVDC) as a chlorine source that works in an undivided cell and applies to a good number of examples. This method works on commodity polymers such as waste PVDC-PVC pharma blister film, PVDC-PO multilayer food packaging, and compression molded sheets of Ixan PVDC (with heat stabilizer) with similar efficiency. Furthermore, this method also provides the dechlorination of PVDC up to 98 %, leading to unsaturated dechlorinated material. Converting PVDC into more stable unsaturated compounds, the release of harmful chlorine-containing gases during incineration can be minimized. Additionally, this method is not only restricted to batch processes but an electroflow process for PVDC dechlorination and electrosynthesis has also been demonstrated.

10achlorination10aElectrochemical recycling10aElectroflow-synthesis10aGraphitic material10aPolyvinylidene chloride1 aMishra, Subhadip1 aKar, Sourav1 aRangappa, Raghavendrakumar1 aPatil, Prashant1 aKadam, Vijay1 aChikkali, Samir, H.1 aSamanta, Ramesh, C. uhttps://library.ncl.res.in/content/electrochemical-deconstruction-waste-polyvinylidene-chloride-pvdc-value-added-products-batch02608nas a2200265 4500008004100000022001400041245009400055210006900149260000800218300000800226490000700234520172000241653002601961653002501987653002302012653002602035653002402061653002202085100001902107700002202126700002002148700002802168700002302196856012302219 2025 eng d a0250-470700aEnhancement of mechanical and rheological properties of PA-12 through silane modification0 aEnhancement of mechanical and rheological properties of PA12 thr cDEC a1460 v483 a

This research examines the effects of silane modifications on polyamide 12 (PA-12) to improve its mechanical and thermal properties. The study employs a reactive extrusion technique to integrate various silanes-Dynasylan (R) AMEO, Dynasylan (R) 1189, Dynasylan (R) DAMO and Dynasylan (R) VPS 4721-at different concentrations (0.25, 0.5 and 0.75%). Key findings reveal that silane modifications significantly enhance the tensile strength, impact resistance and viscoelastic behaviour of PA-12, with the Dynasylan (R) DAMO formulation achieving the highest tensile strength of 38.25 MPa vis-& agrave;-vis 8.02 MPa for PA-12. The modifications also resulted in a reduction of crystallinity by over 35%, contributing to improved toughness and impact strength. Rheological assessments indicate that the flow properties of PA-12 are positively altered, enhancing its complex viscosity and storage modulus, which are crucial for applications in automotive and aerospace industries. Thermal analysis through differential scanning calorimetry and thermogravimetric analysis confirms improved thermal stability, particularly in the 0.5% Dynasylan (R) AMEO-modified sample, exhibiting an onset temperature of 421.87 degrees C. The study emphasizes the importance of the silane type and dosage in tailoring PA-12's performance for advanced applications, suggesting future research directions to further refine silane-modification techniques for enhanced polymer performance. This research provides valuable insights into polymer-modification strategies, highlighting the potential for silane treatments to optimize the mechanical, thermal and rheological properties of PA-12 for diverse industrial applications.

10amechanical properties10aPolyamide 12 (PA-12)10areactive extrusion10arheological behaviour10asilane modification10athermal stability1 aJadhav, Pravin1 aMahajan, Digvijay1 aPatil, Prashant1 aUmbarkar, Shubhangi, B.1 aPol, Harshawardhan uhttps://library.ncl.res.in/content/enhancement-mechanical-and-rheological-properties-pa-12-through-silane-modification03221nas a2200313 4500008004100000022001400041245015500055210006900210260000900279300001600288490000700304520212700311653002402438653002502462653003102487653001502518653002602533100002802559700001802587700002702605700002602632700002002658700002702678700001702705700001802722700002202740700001802762856012702780 2025 eng d a1944-824400aUnderstanding the structural characteristics of modified ceramic hollow fiber oxygen transport membranes through in silico tomography simulation study0 aUnderstanding the structural characteristics of modified ceramic cJUL  a43820-438290 v173 a

Design and development of integrated membrane reactor systems are gaining attention as a sustainable solution capable of performing multiple functions in a single reactor. Membrane reactors made of mixed ionic-electronic conduction materials dosing pure O to the reactions can be exploited for various catalytic processes. In this case, micro- and macrostructures of the membrane surface play a significant role in the permeation performance of membranes, and understanding these parameters prior to scaling up to modules is imperative. Here, 3D X-ray tomography imaging, a versatile nondestructive instrumental technique, is used in understanding the structural behavior of the membrane walls at different structural alignments, leading to anticipation of fouling areas upon assembling membrane reactors. La0.6Sr0.4Co0.2Fe0.8O3-delta hollow fiber membranes are fabricated by the phase inversion method and further modified by the optimized acid etching technique. In silico simulations on different morphologies before and after surface modifications are carried out under varying flow rates at nonambient temperatures to mimic real experimental conditions. Critical parameters such as gas velocity, pressure exerted on cavity walls, and strain, dictating structural integrity of the fibers under experimental conditions, were evaluated. As a result of the assessment, the surface-modified structural morphology with finger-like cavities initiating from the inner wall of the membrane was found to be robust. Increase in the pore size, nonuniform pore size distribution, and irregular and interdigitated cavities formed in outer fingered membranes after multiple surface treatments led to an similar to 5 fold increase in the average pressure exerted at the cavity walls when compared to inner fingered membranes. Strain profile generated for inner fingered membranes shows homogeneous distribution of strain for the applied stress throughout the 3D geometry of the membrane. This detailed structural analysis of the membrane will help in building a more robust and efficient system for scale-up applications.

10a3D X-ray tomography10ain silico simulation10aoxygen transport membranes10aperovskite10aphase inversionmethod1 aJogdand, Shunottara, M.1 aSharma, Jyoti1 aKhilari, Rushikesh, S.1 aMahajan, Digvijay, P.1 aPatil, Prashant1 aPol, Harshavardhan, V.1 aTorris, Arun1 aAgrawal, Ravi1 aKharul, Ulhas, K.1 aDevi, Nandini uhttps://library.ncl.res.in/content/understanding-structural-characteristics-modified-ceramic-hollow-fiber-oxygen-transport02707nas a2200241 4500008004100000022001400041245011300055210006900168260000900237300001400246490000600260520184600266653002002112653002002132653006402152653001402216653001202230100001902242700002002261700002302281700003102304856013002335 2025 eng d a2637-610500aUpcycling of postconsumer recyclate polypropylene into low warping and high toughness 3D printable filaments0 aUpcycling of postconsumer recyclate polypropylene into low warpi cJUN  a7373-73810 v73 a

Polypropylene (PP) is widely used in commodity applications owing to its chemical stability, mechanical properties and low cost. However, almost 50% of the produced PP ends up as postconsumer waste (PCW) within a short period of usage. Being a non-biodegradable polymer, recycling PCW PP is important to mitigate plastic waste in landfills. Nonetheless, recycling or upcycling postconsumer recyclate (PCR) PP into valuable resources without deterioration in physical and mechanical properties is a challenge. This report presents an approach to upcycle PCR polypropylene (rPP) into high quality 3D printing filament that not only prints with very low warpage but with significantly high elongation at break and toughness. Incorporation of poly(butylene adipate-co-terephthalate) (PBAT) along with maleic anhydride grafted polypropylene (MAPP) in specific proportions led to a significant enhancement in mechanical properties, miscibility, crystallization behavior, and 3D printability. rPP/PBAT blends with 20 wt % PBAT and 10 wt % MAPP exhibited a 62-fold enhancement in elongation at break over rPP (from 1.88 to 118.29%) and a 72-fold increase in toughness (from 2 to 143.60 kJ/m3) with almost similar tensile strength. The final printed components had better layer adhesion and structural stability with a dramatic decrease in warpage, from 25.82% for pristine rPP to only 7.86% for rPP/PBAT blend. Isothermal crystallization studies and data analysis using the Avrami equation showed that crystallization half-time (t 1/2), which measures the duration needed for half of the total crystallinity to form, increased from 12.6 s for rPP to 66 s for the rPP/PBAT blend. This report demonstrates an approach to upcycle PCR PP, a positive step toward realizing the goals of circular economy and sustainable additive manufacturing.

10aCrystallization10aFFF 3D printing10apolypropylene/poly(butylene adipate-co-terephthalate)blends10atoughness10awarpage1 aGopal, Animesh1 aPatil, Prashant1 aPol, Harshawardhan1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/upcycling-postconsumer-recyclate-polypropylene-low-warping-and-high-toughness-3d-printable