A study on adsorption of gases in the thin film nanocomposites

Separation of greenhouse gases through polymeric thin film by the selective transport of gas are immense advantages such as light weight, economical, high process flexibility and less space requirement. The thin film technology is used in post combustion process as well as pre combustion processes. This thin film mixed matrix composites (MMC) is prepared using inorganic nanofiller and polymer matrix. In this study, the effect of Lanthanum Oxide (La2O3) nanofiller on the N2 gas adsorption properties of polysulfone (PSf) composite is reported. The solvent evaporation technique is used for synthesizing the film composite. To complete the polymerization of the thin film, the film kept in oven at 90°C for 210 minutes. The morphology of the thin film composite is investigated by Field Emission Scanning Electron Microscope (FESEM) and the chemical structure of the composite is also confirmed through Fourier transform infrared spectroscopy (FT-IR). The performances of the thin film on adsorption are characterized by gas adsorption techniques in measurement of N2 gas. The La2O3 thin film composite significantly improved (31%) N2 gas adsorption when compared to the neat thin fil

Solvent casting-assisted synthesis of thermally responsive shape memory polymer and its composites

The present study illustrates a simple and universally applicable method of synthesizing a new thermal stimuli-responsive thermoplastic shape memory polymer (SMP) and its composites through solvent casting method followed by the hot-pressing technique using polymers like polyvinyl acetate, polysulfone and polystyrene. The process parameters have been optimized to get a uniform film without any phase separation. Polyaniline (PANI), Al2O3, TiO2 and their combinations with PANI such as Al2O3–TiO2, Al2O3–PANI, and TiO2–PANI have been used as fillers to obtain the shape memory polymer composites (SMPCs). Under the thermal stimulus, the shape recovery rate of the SMPC containing Al2O3–PANI hybrid filler was faster, having a quick response time (150 s) compared to the response time of the neat SMP (210 s). Moreover, the SMP containing Al2O3 + TiO2 filler exhibited a higher Young’s modulus (˃ 62%) compared to the neat SMP. The maximum stress of 37 MPa and 4.5% recoverable strain was observed in the SMP containing Al2O3 + TiO2 hybrid filler. Interestingly, no stored strain evolved upon cooling below Tg. The effect of physical aging on the mechanical and thermomechanical properties of SMP and its composites was studied. The synthesized SMP polymer is environmentally friendly and showed an excellent shape memory effect exhibiting a high Tg (~ 80 °C), self-healing property and good mechanical properties. Due to the multifunctional properties of the newly designed SMP and its composite, it may be a promising material for load-bearing applications

Tailored poly(ethylene) glycol dimethacrylate based shape memory polymer for orthopedic applications

Shape-memory polymers (SMPs) are stimuli-responsive materials known for their outstanding ability to be actuated from temporary shape into original shape. Because of this unique functionality SMPs are promising materials for diverse technological applications including smart biomedical devices. In this article, the work has been focused towards tailoring the SMP precursor and crosslinker wt% to obtain biocompatible acrylate based shape memory polymer with glass transition temperature (Tg) close to human body temperature. Methacrylate based shape memory polymer networks are synthesized via free radical polymerization by varying the wt% of t-butyl acrylate (tBA) and poly(ethylene glycol) dimethacrylate (PEGDMA) as crosslinker. The Tg is found to increase from 28 to 45 °C with increasing tBA amount. The SMP synthesized from 70 wt% of tBA and 30 wt% of PEGDMA possess Tg close to human body temperature and is tested for cytotoxicity with two different cell lineages, osteosarcoma (MG-63) cells, and human keratinocyte (HaCaT) cells. The synthesized SMP is found to be non-cytotoxic. Thus the investigated biocompatible shape memory polymer network can be a promising soft substrate for passive thermomechanical stimulation which can adapt and meet specific needs of in vitro or in vivo orthopedic Superior Labrum Anterior and Posterior (SLAP) medical devices

Effect of the addition of diurethane dimethacrylate on the chemical and mechanical properties of tBA-PEGDMA acrylate based shape memory polymer network

There is a great demand for the synthesis of acrylate based thermoset shape memory polymer (SMP) associated with one monomer and one crosslinker such as tert-butyl acrylate (t-BA) with poly (ethylene glycol) dimethacrylate (PEGDMA). The present work describes the synthesis of a new thermoset SMP wherein a second monomer such as diurethane dimethacrylate (DUDMA) has been added to the existing tBA + PEGDMA SMP matrix. The synthesized thermoset shape memory polymer exhibited a glass transition temperature (Tg) of 55 °C, higher Young's Modulus of 3.23 GPa, transmittance of 95% and 100% shape recovery. The SMP exhibited response to both thermal and chemical stimuli. The shape recovery rate of the SMP network is 20 s compared to 24 s observed for SMP based on tBA + PEGDMA. The obtained SMP is very transparent and possesses higher stiffness (8 MPa) and hence may be suitable for biomedical shape memory lens and orthopedic application

Tailored poly(ethylene) glycol dimethacrylate based shape memory polymer for orthopedic applications

Shape-memory polymers (SMPs) are stimuli-responsive materials known for their outstanding ability to be actuated from temporary shape into original shape. Because of this unique functionality SMPs are promising materials for diverse technological applications including smart biomedical devices. In this article, the work has been focused towards tailoring the SMP precursor and crosslinker wt% to obtain biocompatible acrylate based shape memory polymer with glass transition temperature (Tg) close to human body temperature. Methacrylate based shape memory polymer networks are synthesized via free radical polymerization by varying the wt% of tbutyl acrylate (tBA) and poly(ethylene glycol) dimethacrylate (PEGDMA) as crosslinker. The Tg is found to increase from 28 to 45 °C with increasing tBA amount. The SMP synthesized from 70 wt% of tBA and 30 wt% of PEGDMA possess Tg close to human body temperature and is tested for cytotoxicity with two different cell lineages, osteosarcoma (MG-63) cells, and human keratinocyte (HaCaT) cells. The synthesized SMP is found to be non-cytotoxic. Thus the investigated biocompatible shape memory polymer network can be a promising soft substrate for passive thermomechanical stimulation which can adapt and meet specific needs of in vitro or in vivo orthopedic Superior Labrum Anterior and Posterior (SLAP) medical devices

A novel shape memory polymer composites with grafted hydroxyapatite nanoparticles for high strength and stiffness applications

Shape memory polymer (SMP) composites have evolved uniquely, employing nanoscale fillers, which add multifunctionality to the basic resin. In this work, the effect of inorganic, grafted hydroxyapatite (g-HAp) nanoparticles on the dynamic (mechanical), thermo-mechanical and microstructural properties of copolymer, based on diurethane dimethacrylate (DUDMA), (t-butyl acrylate (tBA), and crosslinker poly(ethylene glycol) dimethacrylate (PEGDMA), has been investigated. The agglomeration of nanofillers is limited by using PEG dimethacrylate monomer to graft HAp nanoparticles. Importantly, it is observed that mixing DUDMA in (tBA + PEGDMA) has improved the Young's Modulus of SMP composite to 5.4 GPa at RT (comparable to aircraft grade resin) with a glass transition temperature (Tg) of 55°C. Tensile stress is high as 51.46 MPa with improved strain at failure from 0.07% to 0.05%. The elongation strains of 4–8% are achieved, which provide the required strain compatibility to develop aerospace SMPs as well as SMP composites for structural and bio-medical applications