Poly(1-hexene-co-maleic anhydride) derivatives containing various lengths of linear alkyl side chains (C₁₁–C₂₂) were experimentally evaluated as drag reduction agents in the turbulent flow of Iraqi crude oil using a circulating flow loop system. Good drag reduction performances were obtained. The results showed that the drag reduction has been influenced by the flow rate, concentration, chemical structure, molecular weight, and temperature. Their mechanical stabilities were also investigated using a cylindrical rotator device, and a good relationship was obtained between copolymers' drag reduction efficiency and branch length, in which longer branches significantly enhance copolymer mechanical stability.

Poly(pentaerythritol adipate), poly(pentaerythritol sebacate), and poly(pentaerythritol hexadecandioate) derivatives containing different length alkyl branches were synthesized by two subsequent steps; the reaction of pentaerythritol with (C8-C16) linear aliphatic monocarboxylic acids and then, polymerization of products with (C6-C16) linear aliphatic dicarboxylic acids, using 1% para toluene sulfonic acid as a catalyst. The products were purified and characterized by FTIR, 1H NMR, and 13C NMR spectroscopy. End group analysis was also used as a molecular weight determination technique. The drag-reducing properties of those polymers were investigated in the turbulent flow of Basrah light crude oil using a closed-loop circulation system. Some were found to perform very well DRA and drag reduction efficacy of polymer was further found to be dependent on flowrate, polymer concentration, medium-temperature, and its chemical structure. Also, the effect of the imposed mechanical shear on the polymer stability as a function of time has been investigated using a cylindrical rotator device. It was observed that distance between branch points plays a direct role in contributing to the polymer performance and its mechanical stability.

Introduction: Chitosan is one of the natural polymers can generally consider as a biocompatible and biodegradable polycationic polymer, which has minimum immunogenicity and low cytotoxicity. Therefore, chitosan and its derivatives may represent potentially safe cationic carriers for use in gene delivery.Materials and Methods: Chitosan with 90.1 DD% obtained by deacetylation of chitin extracted from local shrimp shells. Graft copolymerization of L-lactide onto chitosan was carried out at room temperature by ring opening polymerization under a nitrogen atmosphere to prepare chitosan-g-poly (N-lactide) graft copolymer. It was obtained in good yield and characterized by FTIR. The samples purity and concentration were detected using both Nanodrop UV-spectroscopy and agarose gel electrophoresis techniques. The human heat shock proteins gene, hsp-70, was used as a model of human genes to study the effect of chitosan-g-poly(N-lactide) graft copolymer. Results and Discussion: The results revealed that chitosan-g-poly (N-lactide) graft copolymers had safety effect on the DNA, and binding with it. the human heat shock proteins gene, hsp-70, was used as a model of human genes to study the effect of chitosan-g-poly(N-lactide) graft copolymer, it shows a good binding ability the human gene, implies that it might be used in biomedical applications in the future. Conclusions: Grafting of L-lactide onto chitosn by ring opening polymerization was confirmed by FTIR. The repaired polymer has safety effects on human DNA and genes. The chitosan-g-poly (N-lactide) graft copolymer has shown high efficiency to electrostatic interaction with human DNA and gene, implying that it is suitable to be used as DNA and gene delivery.

In this study, modification of poly(adipic anhydride) through branching its chains was carried out via melt condensation polymerization with D-mannitol. The percentage of mannitol was varied (3, 4, 5, 10, 15, and 20 Wt.%) and the resulting copolymers were purified and characterized by FT-IR and ¹³C-NMR. These analyses indicated that linear chains of poly(adipic anhydride) can react with strong nucleophiles and dissociate to produce highly branched poly(adipic anhydride-co-mannitol adipate) which confirms the validity of the proposed mechanism. The copolymer’s molecular weight characteristics have been also examined using GPC analysis. Thermal properties of copolymers were also investigated using TGA, DTG, and DCS analyses. TGA/DTG revealed that the thermal degradation of copolymers proceeds in multi-stage decomposition, whereas the shift and pattern change of the melting point peak of DSC curves can identify the weight percentage of mannitol for homogenous copolymers. Two non-isothermal models, the Flynn–Wall–Ozawa and Kissinger methods, have been also employed to analyze thermogravimetric data collected from the thermal decomposition of the copolymers and found that Flynn–Wall–Ozawa method provides better results with R² correlation up to 99.3%. The activation energy in the region of T_max was determined and found that an increase in mannitol contents in copolymer has a positive impact on its thermal stability.

The aim of the article is to study the influence of environmentally friendly palm frond ash on the mechanical and thermal properties of polyurethane used as filler. Various weight filler ratios with particle sizes around (125 μm) were examined and characterized using elongation, tensile strength, Young's modulus, compressive strength, average burning time, and infrared spectroscopy. The results showed that the addition of 20 wt.% palm frond ash powder significantly improved the hardness mixture by about 2.83 MPa. In addition to that, the highest value of the compressive strength of the polymer with the additive was recorded at 10 wt.%. Also, the most excellent value of Young’s modulus was 2 MPa at a ratio of 50 wt. %, as was the average burning time of about 33 sec. The mechanical properties of polyurethane were affected by adding palm frond ash, which increases the tensile and compressive strengths, making it suitable for use in many applications. Moreover, the environmentally friendly material reflects the benefits of waste recycling. The addition of filler affects the morphology and strengthens the brittleness. Additionally, the use of fly ash from palm frond combustion in the technology of polyurethane materials complies. Partial replacement of petrochemical components with waste filler also reduces the total energy consumption in producing PU composites.