الفهرس | Only 14 pages are availabe for public view |
Abstract Polyurethanes are one of the most important industrial products exhibiting versatile properties suitable for use in many fields as coatings, adhesives, sealants, and foams. Considering the continuous depletion of fossil feed stocks, dramatic fluctuations in the oil price, and environmental issues, academic and industrial researchers are devoting increasing attention and efforts to the utilization of renewable resources with comparable properties as raw materials for the production of polyurethanes. This research is focused on exploiting vegetable oils in the preparation of biobased polyols and polyurethanes due to their low toxicity, inherent biodegradability, ready availability, and relatively low price. Vegetable oil-based polyols are another promising monomer, which can react with diisocyanates to afford polyurethane elastomers which have various applications in printing inks and coatings. Chapter 1 contains a general introduction about various types of polymeric packaging sheets and films. Types of printing techniques and inks used based on their specific functions both the film and the ink. In chapter 2, Synthesis of polyurethane elastomers prepared via the prepolymer method was adopted; the PU was characterized for the the following features: 1. Chemical structre validation for both reactants and products using Fourier transform infrared (FT-IR) spectroscopy in absence and resence of chain extenders, diisocyantes and polyols. 2. Molecular weight determination (Mw, Mn, and DP) using Gel Permeation chromatography (GPC), 3. Flow and fluidity character was achieved through viscosity measurements. 4. Solid content and solubility in common solvents.5. Printing ink films were designed using these PUEs as a plasticizer and their optical properties were tested by X-rite, gloss. Other properties such as mechanical properties as crinkle test, curling resistance and adhesion strength, and thermal properties as heat and freeze resistance were examined. The results proved that the samples of PUEs were hydrophobic and this nature was increased as the chain extender length was increased, also all PUEs show low molecular weights and viscosities. Thermal tests was performed to analyze the thermal behavior of the printing inks which showed that all the PUEs were stable up to 200 oC and showed very good freeze stability. All mechanical tests showed very good results with slightly increase with aromatic isocyanates. Chapter 3 describes practically the effect of replacing 50% of petroleum based polyol by castor oil and vegetable oil-based polyols prepared by ringopening of epoxidized vegetable oils (soybean and palm olein) with different ring openers (Water, Methanol and Ethylene glycol). The properties of the resulting polyols were investigated. It was characterized for viscosity, hydroxyl number, acid value, molecular weight, FT-IR, and DSC revealing all changes with regard to chemical structural features and its prelative physical properties. Moreover, the properties of final PUs prepared from castor oil, palm olein polyols and methoxylated soybean oil polyol were compared with standard PU. The effect of bio-component on the chemical and thermal stability of resulting PU was again recharacterized for comparison reasons and efficiency. Printing ink films were designed using these prepared PUEs as a plasticizer and were tested for optical properties by X-rite, gloss, mechanical properties as crinkle test, curling resistance and adhesion strength, and thermal properties as heat and freeze resistance. The results revealed that the chemical structure of these polyols and their functionality primarily dictate performance properties and their end-use applications. The results proved also t+hat the samples of biobased PUEs are found as hydrophobic in nature, in addition, all the PUEs showed low molecular weights and viscosities. The thermal behavior study of printing inks indicated that all the PUEs were stable up to 180oC and demonstrate very good freeze stability except palm olein based polyurethanes (PU PM 50 and PU PW 50). All derived inks from bio-based oils displayed approved values for the mechanical tests with slightly increase for the samples PU-CO 50 and PU- SB 50. |