Polyethylene Vinylacetate (EVA) Student Name Pathik Patel, ID Number #20638625; E-mail: email@example.com 1. Introduction and Applications: Ethene, but-3-enoic acid (IUPAC name), commonly known as poly(ethylene-vinyl acetate) (PEVA), as the name suggest, is the copolymer made up of ethylene monomer and vinyl acetate (VA) monomer. It is produced by addition reaction mechanism with free radical initiation. It has a chemical formula of (C2H4)n(C4H6O2)m. Depending upon the weight percent of vinyl acetate, we get different polymers such as vinyl acetate modified polymer (4% VA), thermoplastic ethylene vinyl acetate (4 - 40% VA) and ethylene vinyl acetate rubber (>40% VA) with the remainder being ethylene. Properties such as toughness, …show more content…
Synthesis, Mechanism and Production In free-radical co-polymerizations, the different reactivity of the growing polymer chain toward two different monomer molecules and the possibility of chain transfer reactions make calculations to predict polymer kinetics and composition extremely difficult. The first equation shows ethylene-terminated polymer radical reacting with vinyl acetate, and the second equation shows vinyl acetate terminated polymer radical reacting with ethylene. The propagation rate coefficient are used to find the reactive ratios. It is even possible to consider the effects of penultimate groups. It is observed that longer alkyl chain has little effect on the kinetic parameters. However, it was noted that there is a relatively small penultimate unit effect, if any, for this copolymerization. The reactivity ratios for ethylene-vinyl acetate copolymerization have been measured by a number of workers, and vary from r1 = 0.13 to 0.88 and r2 = 0.72 to 3.74, where r1 = k11/k12 and r2 = k22/k21. Reactivity ratios are sensitive to reaction temperature, pressure and media, which accounts in part for the broad range reported. the lower temperature and higher pressure conditions increases the reactivity ratios slightly. The table below depicts Reactivity Ratios at Various Temperatures for Ethylene-Vinyl Acetate Co-Polymerization, Where 1 = Ethylene and 2 = Vinyl
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Service life In terms of the effect of service life on the polymer, this additive has a long service life. Polyvinyl chloride is a substance that has this additive inside it. Due to this the additive makes the polymer stronger and makes the product last longer.
Based on the data obtained, Table 1 shows that the polyester formed from ethylene glycol and phthalic anhydride formed a red/ violet/ brown color; it also had a hard/ solid viscosity and was brittle when pressure was applied. This type of result was expected from ethylene glycol because this sort of polyester is linear and results from each of the starting materials having 2 functional groups. It is also an example of a thermoplastic polymer, meaning that it is soft above a certain temperature, however, solidifies upon cooling. Table 1 also shows that the polyester formed from glycerol and phthalic anhydride had a brown color, a sticky/ solid viscosity, and did not break apart when pressure was applied. However, this result was not expected because the glycerol and phthalic anhydride polymer were supposed to be clear in color and have a hard/ solid viscosity.
It is a thermoplastic resin that is retrieved by the polymerization of ethylene. PE is a semi-crystalline polymer that has excellent chemical stability. Specifically, it is able to store high quantities of water insoluble components, such as most volatile molecules, due to its polyolefin nature. This occurrence is known as the aroma scalping, which causes a diminishment of content of aroma and/ or an imbalance. The stiffness, hardness and strength of the PE attain greater heights with an increase in the density of chain branches. Not only do containers made up of PE form stiff and strong holders, but they also lead to reduced moisture vapour transmission and clarity or transparency based on the density of polymer
Synthesis of a Liquid Crystal – Cholesteryl Benzoate Introduction The acyl chloride is a convenient reactant when undertaking ester synthesis, this is because it is highly reactive. Therefore, it can drive the reaction to completion and ensure a high yield. The high reactivity of the acyl chloride is due to the electronegative chlorine atom which pulls the electrons towards it in the C-CI bond. Furthermore, this makes the carbon atom more electrophilic and therefore easier for nucleophiles to react with. The chloride ion is a weak base and therefore acts as a good leaving group.
Making nylon 6,6 is even easier if you use a diamine and a diacid chloride instead of a diacid. This is because acid chlorides are much more reactive than acids. The reaction is done in a two-phase system. The amine is dissolved in water, and the diacid chloride in an organic solvent. The two solutions are placed in the same beaker. Of course, the two solutions are immiscible, so there will be two phases in the beaker. At the interface of the two phases, the diacid chloride and diamine can meet each other, and will polymerize there. There is special way to do this called the "Nylon Rope Trick"4, and we'll show you how to do that in just a minuteMaking nylon 6,6 is even easier if you use a diamine and a diacid chloride instead of a diacid. This is because acid chlorides are much
Before using ethylene to produce polyethylene, the compound needs to be purified to almost 100%. In order to reach this level of purity the ethylene needs to be freed of olefins, acetylenes, dienes and water through several processes such as: driers are used to take out the water, a demethanizer is used to remove methane, etc. ...
Figures 3a-d show the effect of polymerization time on %GY (Fig. 3a) ; %GE (Fig. 3b); %TC (Fig. 3c) and %HP (Fig. 3d) at four different temperatures ( 50 0 ; 60 0 ; 70 0 and to 80 0C ). It is evident that , as the reaction time became longer , all polymer yield , except %GE , increased. The polymerization time corresponds to 180 min. brought about the maximum percentages for the positively dependence of polymer criteria.
It is a kind of plastic that originates from consolidating ethylene (found in unrefined petroleum) and chlorine (found in salt). At the point when joined together these substances get to be Polyvinyl Chloride (PVC) gum, or as it is better known - Vinyl. It is then further handled to be made more adaptable, inflexible, semi-fluid, clear or bright, thick or thin.
Ethylene, H2 C = CH2, the lightest olefin. It is a colorless, flammable gas, produced mainly by thermal decomposition in the presence of steam (steam cracking) from petroleum-based raw materials. Ethylene has virtually no direct inhalation, but almost exclusively acts as an intermediate in the production of other chemicals, especially plastics. Polyethylene, which is the most commonly used plastic, is directly produced from ethylene by its polymerization. Ethylene can also be chlorinated or combined with benzene to produce 1,2-dichloroethane, a precursor of plastic polyvinyl chloride to produce ethylbenzene, which is another important plastic used in the manufacture of polystyrene. Lesser amounts of ethylene are oxidized to produce chemicals containing ethylene oxide,
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
about, you’ll have to talk about what monomers and polymers are, what the entire process of
This research brought me experience in many areas of material science: monomer preparation and purification, polymerization, polymer precipitation, and film casting. I created the monomer and worked through every step to film production and testing without needing supervision. I also had to learn and perform air-free techniques involving glove boxes and Schlenk lines. Difficulties with the different reaction conditions and ratios needed for each monomer to form correctly made every run a test of
Polyurethanes are made by the exothermic reactions between alcohols with two or more reactive hydroxyl (-OH) groups per molecule (diols, triols, polyols) and isocyanates that have more than one reactive isocyanate group (-NCO) per molecule (diisocyanates, polyisocyanates). For example, a diisocyanate reacts with a ethane-1,2-diol:
A polymer is a large molecule that is known as an organic compound. Polymers are used in many different ways to form different structures but mostly polymers are used to create various kinds of plastics. A polymer is made from the covalent bonding of smaller repetitive molecules. As seen in figure 1. These repeating molecules are built into chains, and different polymers have varied chain lengths. These smaller molecules which make up the polymer are known as monomers. Through the reaction of polymerization which generally requires a catalyst polymers are formed. Various Polymers are built of different types of monomers, some contain only one type of monomer whereas others can contain up to two or more monomers. These polymers are known as natural polymers, they occur in nature and then are extracted for use. Natural polymers are often water based, examples are silk,