Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

The Effect of Fluid Velocity on the Diffusion of Trimethylene Glycol through a Reverse Osmosis Membrane in Microchannel -X

The study aims to observe the diffusion process which is influenced by different velocity and fluid concentrations. Using a microfluidic system and the diffusion process through a reverse osmosis membrane. The research was carried out by flowing fluid into the microchannel. The diffusion process is known by measuring and analyzing the density of liquid waste aquades-trimethylene glycol. The results showed the amount of diffusion through the membrane was influenced by flow velocity and fluid concentration. this is because the velocity of the flow produces pressure on the wall so that it pushes the fluid to diffuse through the membrane.

Genotoxin Effect of Composite Resin

At this moment composite resin is the most widely used material for dental restoration. The content of the resin is a mixture of monomer bisphenol A glycidyl methacrylate (Bis-GMA), trimethylene glycol dimethylmethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) and special particle fillers made of radioopaque glass. Many studies have been conducted to study the biocompatibility of composite resin, especially the cytotoxicity and genotoxicity test. Genotoxicity tests that are often carried out are comet test for DNA damage protection and micronuclei test for protection of genome damage. The monomer content of composite resins can have a genotoxic effect.

Synthesis and characteristics of biobased copolyester for thermal shrinkage film

A series of poly(1,4-cyclohexanedimethyl-trimethylene glycol terephthalate), (PCTG), co-polyesters were synthesized using 1,3-propanediol (PDO) and 1,4-cyclohexanedimethanol (CHDM) via melt polymerization.

Boronic acid and boronic ester containing polyoxometalates

Three organoboron functionalized polyoxometalates have been synthesized using Schiff base chemistry including a boronic acid, its methyl ester and its trimethylene glycol ester.

Theoretical Study of Hydrogen Bond Formation in Trimethylene Glycol-Water Complex

A detailed quantum chemical calculation based study of hydrogen bond formation in trimethylene glycol- (TMG-) water complex has been performed by Hatree-Fock (HF) method, second-order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), and density functional theory with dispersion function (DFT-D) using 6-31++G(d,p) basis set. B3LYP DFT-D, WB97XD, M06, and M06-2X functionals are used to capture highly dispersive hydrogen bond formation. Geometrical parameters, interaction energy, deviation of potential energy curve of hydrogen-bonded O–H from that of free O–H, natural bond orbital (NBO), atom in molecule (AIM), charge transfer, and red shift are investigated. It is observed that hydrogen bond between TMG and water molecule is stronger in case of TMG acting as proton donor compared to that of water acting as proton donor, and dilute TMG solution would inhibit water cluster formation.