A tough, smart elastomeric bio-based hyperbranched polyurethane nanocomposite

Herein, we fabricate an elastomeric nanocomposite using castor oil-based hyperbranched polyurethane (HPU) and iron oxide nanoparticles decorated reduced graphene oxide (IO-RGO) nanohybrid by an in situ polymerization technique. The designed nanocomposite not only exhibits good thermal properties but also possesses excellent mechanical properties such as tensile strength (24.15 MPa), tensile modulus (28.55 MPa) and toughness (110.8 MJ m À3 ). In addition, the nanocomposite demonstrates rapid and repeatable self-healing abilities under exposure of 20-30 s microwave power input (180-360 W) and by direct sunlight exposure (10 5 lux) for 5-7.5 min. It also demonstrates excellent shape-recovery ability under microwave power (30-60 s) as well as in direct sunlight (1-2.5 min). Thus, the studied tough polymeric material has potential advanced applications

Hyperbranched Polyamine as Multipurpose Polymeric Additives for LDPE and Plasticized PVC

The hyperbranched polyamine based on 4,4'-sulfonyl dianiline was obtained by the earlier reported method and used as multipurpose polymeric additives for low density polyethylene (LDPE) and plasticized polyvinyl chloride (PVC). The effect of this hyperbranched polyamine on the processability, mechanical properties, flammability behavior, etc. has been studied. The mechanical properties of the compounded polymers before and after thermal aging and leaching in different chemical media were also studied at dose levels of 1 to 7.5% (w/w) of the additive. SEM study indicates that both polymers exhibit homogenous morphology at all dose levels. The mechanical properties like tensile strength (T.S.) and hardness are improved by incorporation of hyperbranched polymeric additive and these properties increased with the increase of dose level. The flame-retardant behavior as measured by limiting oxygen index (LOI) of all samples indicates an enhanced LOI value compared to the polymer without hyperbranched additive. The processing behavior of all compounded polymers was investigated by measurement of solution viscosity and MFR value. The effect of leaching and heat aging of the polymers on the mechanical properties showed that hyperbranched polyamine is better compared to the commercially used antidegradant, N-isopropyl-Nphenyl p-phenylene diamine (IPPD)

Vegetable Oil-Based Hyperbranched Thermosetting Polyurethane/Clay Nanocomposites

The highly branched polyurethanes and vegetable oil-based polymer nanocomposites have been showing fruitful advantages across a spectrum of potential field of applications.Mesua ferreaL. seed oil-based hyperbranched polyurethane (HBPU)/clay nanocomposites were prepared at different dose levels by in situ polymerization technique. The performances of epoxy-cured thermosetting nanocomposites are reported for the first time. The partially exfoliated structure of clay layers was confirmed by XRD and TEM. FTIR spectra indicate the presence of H bonding between nanoclay and the polymer matrix. The present investigation outlines the significant improvement of tensile strength, scratch hardness, thermostability, water vapor permeability, and adhesive strength without much influencing impact resistance, bending, and elongation at break of the nanocomposites compared to pristine HBPU thermoset. An increment of two times the tensile strength, 6 °C of melting point, and 111 °C of thermo-stability were achieved by the formation of nanocomposites. An excellent shape recovery of about 96–99% was observed for the nanocomposites. Thus, the formation of partially exfoliated clay/vegetable oil-based hyperbranched polyurethane nanocomposites significantly improved the performance

Development of 157 nm Photoresist Polymers for F₂ Laser Lithography

571-585Development of 157 nm photoresist polymers for F2 laser lithography is a great challenge to polymer scientists and technologists. 157 nm lithography has emerged as the promising candidate for extending conventional photolithographic methods to the sub- 100 nm device generation for the electronic applications. Among the difficulties of several daunting materials challenge for this development, transparency of the photoresist polymer is the most difficult job. The review attempts to investigate the problems, significance, and the recent development strategies of photoresist polymers for 157 nm lithography