@article {48389, title = {Biodegradable, solvent-free photocrosslinkable PLLA resin formulations for additive manufacturing}, journal = {Macromolecular Chemistry and Physics}, volume = {223}, year = {2022}, month = {NOV}, type = {Article}, abstract = {

Acrylate end-functionalized linear and star poly l-lactide (PLLA) based aliphatic, photocurable oligomeric crosslinkers are developed, which are formulated with hydroxyl (ethyl)methacrylate (HEMA) as a biodegradable reactive diluent to demonstrate successful application for solvent-less 3D printing using digital light processing (DLP) technique as well as a custom-designed direct ink writing 3D printer. The resin formulation for 3D printing is optimized using spot curing, photodifferential scanning calorimetry and cure depth analysis. The 3D printed parts exhibit promising mechanical property along with improved hydrophilicity and biodegradability. The development of new photocurable resin formulations are expected to meet the growing demand for raw materials that can be applied for developing custom designed bio implantable objects.

}, keywords = {3D printing, biodegradable materials, digital light processing, L-Lactide, photocurable materials}, issn = {1022-1352}, doi = {10.1002/macp.202200139}, author = {Pal, Shibam and Asha, S. K.} } @article {49380, title = {Biocompatible PVAc-g--PLLA acrylate polymers for DLP 3D printing with tunable mechanical properties}, journal = {ACS APPLIED MATERIALS \& INTERFACES}, volume = {16}, year = {2024}, month = {OCT }, pages = {62594-62605}, type = {Journal Article}, keywords = {acid, copolymers, polymerization, TACONIC ANHYDRIDE}, issn = {1944-8244}, doi = {10.1021/acsami.4c11285}, author = {Pal, Shibam and Gavhane, Utreshwar Arjun and Asha, S. K.} } @article {49410, title = {Room temperature photocurable PEEK polymer formulations for high-performance 3D printing applications}, journal = {ACS Applied Engineering Materials}, volume = {2}, year = {2024}, month = {JUN}, pages = {1450{\textendash}1459}, type = {Article}, abstract = {

Digital light processing (DLP) technology was employed to 3D print acrylate-modified poly(ether ether ketone) (PEEK). PEEK and modified PEEK (mPEEK incorporating pendant pentadecyl chain) polymers were synthesized and end-capped with urethane acrylate units. These end-modified PEEK polymers were combined with commercially available (meth)acrylic cross-linkers and photoinitiator to create photocurable resin formulations suitable for DLP 3D printing. The resulting 3D-printed parts exhibited remarkable mechanical strength, with a Young{\textquoteright}s modulus of 2.1 GPa. This surpassed the mechanical properties of commercial acrylate resin 3D-printed parts and achieved approximately 55\% of the Young{\textquoteright}s modulus of reported commercial PEEK polymer. Notably, the thermal properties of the 3D-printed materials were impressive, including a high glass transition temperature of 140 {\textdegree}C and stability with only around 10\% weight degradation occurring at approximately 400 {\textdegree}C. These innovative resins demonstrated excellent printability with high resolution, enabling the fabrication of intricate shapes, including complex dental materials by DLP 3D printing. Their versatility extends to potential applications in dentistry, automobile manufacturing, and robotics.

}, doi = {https://doi.org/10.1021/acsaenm.4c00275}, author = {Pal, Shibam and Gaikwad, Yogesh and Asha, S. K.} } @article {49039, title = {Thiol-ene-based degradable 3D printed network from bio resource derived monomers ethyl-lactate and isosorbide}, journal = {European Polymer Journal}, volume = {205}, year = {2024}, month = {FEB }, type = {Article}, abstract = {

A polymeric ene-based thiol-ene network is reported that was demonstrated for light-based 3D printing. Allyl poly (acrylate ethyl lactate) (PAEL) was synthesized starting from ethyl lactate in an efficient and scalable manner. Ethyl lactate is a biobased material obtained naturally or chemically in high yields in the form of ethyl ester of lactic acid. Isosorbide, which is also a bio based resource was converted into thiol derivative and was used along with Pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) as multifunctional thiol. The polymeric nature of the ene (i.e. PAEL) imparted exceptionally high mechanical properties like Young{\textquoteright}s modulus of 1.75 GPa as well as high thermal stability with a decomposition temperature (Td,10\%) exceeding 350 C for all the networks studied. The properties could also be customized by fine tuning the type and stoichiometric ratio of the thiol crosslinked employed. For instance, the Young{\textquoteright}s modulus range from 1.75 GPa to 1.03 GPa and glass transition temperature range from 44 C to 54 C could be achieved. DLP 3D printing was used to demonstrate the printability of the resins with high resolution and structural fidelity. The study also highlights the basemediated rapid hydrolytic degradation efficiency of the 3D printed parts, demonstrating the applicability of these novel polymeric ene based thiol-ene for sustainable and eco-friendly 3D printable formulations.

}, keywords = {3D printing, Degradation, digital light processing, Poly (acrylate ethyl lactate), Thiol-ene}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2024.112761}, author = {Pal, Shibam and Asha, S. K.} } @article {50012, title = {DLP 3D printing and characterization of PEEK-acrylate composite biomaterials for hip-joint implants}, journal = {Obrabotka metallov - Metal Working and Material Science}, volume = {27}, year = {2025}, month = {JAN}, pages = {172-191}, type = {Article}, abstract = {

Introduction.\ Hip joint replacement is considered the most complex and critically important orthopedic surgical procedure compared to knee and shoulder joint replacements. Over the past few decades, there has been significant advancement in hip joint replacement technology, and various biomaterials have been substantially improved. An increasing number of hip joint replacement surgeries are now successful, assisting individuals in regaining normal daily activity and work capacity comparable to their pre-fracture state. However, the need for revision surgery, specifically for implant replacement, is still observed in active patients several years following the initial operation. This underscores the need to develop durable biomaterials and customized hip joint implants to reduce implant wear and the risk of dislocation. This research study explores a novel PEEK-in-acrylate composite biomaterial with varied weight percentages of PEEK (0 \%, 5 \%, and 10 \%) in an acrylate-based matrix. Tests were conducted to determine its properties, biocompatibility, and 3D printability. Based on the developed material, pins (in accordance with the ASTM standard) were fabricated using 3D printing for subsequent wear rate studies. The potential use of the developed composite materials for hip-joint applications was also thoroughly investigated.\ The purpose of this study\ is to develop and investigate a new PEEK in Acrylate composite biomaterial with varied weight percentages of PEEK (0 \%, 5 \%, and 10 \%) in an acrylate-based matrix. The research includes an assessment of the material{\textquoteright}s properties, biocompatibility, and 3D printability. Using digital light processing (DLP) 3D printing technology at room temperature, pins (in accordance with the ASTM standard) were fabricated. An experimental study of dry sliding wear resistance was conducted on the resulting samples to determine the effect of PEEK weight fraction on the wear rate and frictional performance against an SS 316 steel disk. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS) were used to analyze the surface structure and element distribution within the material.\ The Methods of Investigation.\ Digital Light Processing (DLP) 3D Printing technique was used to 3D Print the ASTM pins and Acetabular liner with different weight fraction of PEEK in acrylate. Dry sliding wear tests were carried out using a pin-on-disk tribometer. During testing, the disk rotation speed and the normal load on the pin were varied. The studies were designed to determine the influence of input parameters on the wear rate. A total of nine experiments were conducted for each PEEK weight fraction, with a sliding distance of 4 km per experiment. The load ranged from 20 to 100 N, and the sliding speed varied from 450 to 750 rpm. Surface structure and element distribution were analyzed by Energy-dispersive X-ray spectroscopy (EDS) and Scanning electron microscopy (SEM).\ Result and Discussion.\ Current study demonstrates the advantages of varying the weight fraction of PEEK in Acrylate for DLP-fabricated biomaterials. Analysis of the SEM, EDS, and wear testing results indicated that the composite with 10 wt \% PEEK in Acrylate exhibited superior microstructural integrity, elemental homogeneity, and significantly improved wear resistance. The 10 wt \% PEEK in Acrylate composite, fabricated via DLP 3D printing, is suitable for biomedical implant and healthcare applications

}, keywords = {3D printing, Biomaterials, FDM, implant, PLA, print orientation, wear behavior}, doi = {10.17212/1994-6309-2025-27.1-172-191}, author = {Dama, Yogiraj and Jogi, Bhagwan and Pawade, Raju and Pal, Shibam and Gaikwad, Yogesh} }