Vinyl Ester vs Polyester Resins Pros and Cons of Each

For many applications, making the right selection between these resins can affect strength, durability, product life and, of course, cost. They have different chemical compositions and these differences express themselves in their physical properties. Before choosing between them for a particular application, it is important to have a clear idea of what performance is required from the build. Understanding the differences between these resins will help a user to compile the list of critical material performance factors required from the finished article and inform the selection. The Differences Polyester resins are formed by the reaction between polyols such as glycol or ethylene glycol with dibasic acids such as phthalic acid or maleic acid. These unsaturated resins are combined with other chemicals sometimes called hardeners or catalysts. This changes the molecular structure and the resulting compound cures, generating heat in the process. Methyl ethyl ketone peroxide (MEKP) is one such hardening agent. Vinyl ester resins are produced by the reaction (esterification) between an epoxy resin and an unsaturated monocarboxylic acid. Essentially they comprise a base of polyester resin strengthened with epoxy molecules in the backbone of the molecular chain. Vinyl esters also use peroxides (e.g. MEKP) for hardening. Both resins can be thinned by reaction with chemicals such as styrene. Advantages and Disadvantages On a broad scale of viscosity, vinyl esters are midway between polyesters and epoxy resins, before adding styrene. Thinning effects workability and strength - thinning reduced strength but makes it easier to brush or spray. Vinyl esters are more tolerant of stretching than polyesters. This makes them more able to absorb impact without damage. They are also less likely to show stress cracking. Vinyl ester has fewer open sites in its molecular chain. This makes it much more resistant to water penetration (hydrolysis) which can cause osmotic blistering. Vinyl esters shrink less on curing, which means that pre-release of a laminate from a mold is less significant. Vinyl esters are more tolerant of stretching than polyesters. This makes them more able to absorb impact without damage. They are also less likely to show stress cracking. The cross bonding of vinyl esters is superior to that of polyesters. This means that vinyl esters bond to core materials much more effectively than polyesters and delamination is less of an issue. Vinyl esters are less sensitive to ambient conditions (temperature and humidity) than are polyesters. Vinyl esters are more expensive than polyesters through careful calculations are required to assess the cost impact of a significant build project such as a luxury yacht. This is because the relative strengths need to be factored in - you can use less vinyl ester to achieve a given strength. Both resins are susceptible to chalking - UV breakdown at the surface - unless an additive is incorporated into the mix. Which to use? Despite the superiority of vinyl ester (apart from cost), polyester still has a large part to play in composite fabrications. Where prolonged exposure to water is likely (such as a boat hull or water tank), then by using polyester for the bulk construction with a surface barrier of vinyl ester, water penetration can be reduced considerably without a significant increase in cost. If improved durability and impact resistance is important, then vinyl esters win over polyesters - and again the build can be tailored to use the vinyl esters in those areas with higher impact probability. However, these are relative and other resins or composites may be superior (and more expensive). Common Uses Vinyl esters and polyesters are widely used  and for many similar applications. However where the physical properties of vinyl ester are more important than cost, then vinyl ester takes the lead: Transportation: parts for automobiles and other surface transportation vehiclesBuilding and Infrastructure: fascias for buildings, reinforcements for bridgesMilitary/aerospace applications Conclusion Before making a decision, consider the requirements for durability very carefully, and weigh up the cost. It may be that the extra cost of vinyl ester will be offset by its superior strength and durability. Then again, maybe both will work well in combination with the application.

Essay on Cuba - 1685 Words

Cuba In the past fifty years we have witnessed the end of the cold war, the end of communism in a vast majority of nations as well as the rise of the United States to being the sole world power. But while the world has greatly changed over the past half-a-century, there has been little change in the Cuban-American relationship. Since the rise of Fidel Castro to power in the early nineteen fifties, the United States has all but cut off all relations with the Cuban government. It has now been thirty-nine years since the United States first imposed its various sanctions on the Cuban government and even though Cuba has faced great hardship and misfortune in recent years due to these sanctions, the United States to this day is still†¦show more content†¦There were few Cubans that supported this annexation of Cuba into the United States control. The majority of the people who supported this were the rich and elite. One such person who opposed the U.S. control over Cuba was Jose Ma rti. Mr. Marti lived in exile in New York for many years until returning to Cuba in 1895. Upon his arrival in Cuba, Marti’ was declared a national hero by the Anti-American supporters. It are the beliefs and ideas of Jose Marti’ that Fidel Castro later based his own ideals upon. In 1882, Marti’ wrote that Cuban independence was a process and not a single event. He said that it would take lots of preparation and dedicated organization in order to achieve independence. (Perez 145) It was this thought process that was instrumental in the â€Å"defining of the most exalted version of Cuba Libre: independence from Spain and the United States. (Perez 146) It were these beliefs that lead to the establishment of the Cuban Revolutionary Party in April of 1892. The goal of this establishment was to liberate Cuba. Marti neverShow MoreRelatedCulture of Cuba1353 Words   |  6 PagesThe Culture Of Cuba Andrew Mengel Moravian College The Culture of Cuba Cuba has a complex but rich culture that has been broadening in all aspects in its society. Its semi-forbidden access to Americans makes it a curious destination for adventitious people. The largest island in the Caribbean, Cuba has been inhabited since the mid-1400s by various Mesoamerican tribes, until 1492 when Christopher Columbus invaded the island and took it over. It remained a colony of Spain until the Spanish-AmericanRead MoreEssay on Cuba580 Words   |  3 Pages Cuba Cuba has been under a dictator named Fidel Castro since 1959 when his army took over the communist party that was running the country. Cuba’s main source of economic growth comes from agriculture and exports to and from Europe. Since America has had an embargo on Cuba since 1962 neither countries trade with each other because of many disagreements about governing techniques and Fidels unwillingness to comply with U.S. instructions. Cuba’s long history and culture has contributed toRead MoreThe Island Of Cuba1624 Words   |  7 PagesThe island of Cuba is located on the northern rim of the Caribbean Sea and was inhabited by Arawak and Ciboney Indians prior to colonization by the Spanish in 1511. This native population, due to the colonization of the Spanish, was ravaged by decease, enslavement and warfare which ultimately caused their extinction. Cuba received little attention throughout the sixteenth and seventeenth centuries like most of Spain’s Caribbean colonies because Spain was concentrating attention on Central and SouthRead MoreCuba1197 Words   |  5 PagesCuba Country Profile International Business Cuba is an island in the Caribbean. (Discuss its culture) The island is located only 90 miles from Florida and is alligator-shaped. Its the biggest island in the Caribbean. The total population is 11,061.886. Its official language is Spanish, and 95% Cubans are Roman Catholic. The major ethnic groups include mulattos, which consist of 51% of the population. The remaining groups include 37% ofRead MoreA Summary of Cuba1975 Words   |  8 PagesItalian, Greek and Roman style. You can see the Spanish influence through the Convento de Santa Clara and the Cuban Baroque is representative through the Plaza de la Cathedral. Cuban Island: Travel Cuba has been a highly sought out place to go for its natural white sand beaches, crystal-clear waters. Cuba is known for three mountain ranges, two-long provinces of savanna. Sugar Mill, Yumurà ­, and Vià ±ales are a few areas known around the world for its abundance of produce. Five hundred species of fishRead MoreIs Cuba The Oldest Profession?991 Words   |  4 Pages Cuba is an Island found in the Caribbean. Cuba is the biggest Island in the Caribbean with an estimated population of about 11 million people. The Island of Cuba like most Islands in the Caribbean has a breath taking scenery. Cuba is and Island highly influenced by the Spaniards not only in its culture, but as well in the colonel architecture. It’s a place where anyone who visits will be able to find a lot of warm-hearted people; it’s a beautiful Island. However, the Island is overshadowed by povertyRead MoreCuba And The United States1610 Words   |  7 PagesIntroduction A lot has gone on between the United States and Cuba between 1959 and 2015. In 1959, Cuba and the United States cut off diplomatic ties. On December 17, 2014, the United States and Cuba announced that they would restore diplomatic ties. 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Those who have not been completely negligent over the last half a century have probably also heard the names Fidel Castro and Ernesto â€Å"Che† Guevara. These two men were very pivotal players in the history of Cuba and its revolution. Literary and cinematic reenactments are a great method for providing historical knowledge. However, they c an be heavily biased and much of the factual evidence canRead MoreCuba And The United States1217 Words   |  5 Pageshe U.S and Cuba officially cut ties in January of 1961, meaning that there have not been any high-level diplomatic relations with Cuba for 54 years. At the time, America and Cuba considered one another as mortal enemies and mistrusted each other’s government greatly. So this raises the question; Was it the correct decision for Cuba and the United States to cut ties? This break with Cuba was a bad decision because it caused Cuba’s economy to plummet, caused Cubans to immigrate, and it caused Cuban

Merchants of Cool free essay sample

In watching the film, Merchants of Cool, which was aired in 2001, it is quite concerning how our society is turning to consuming as a means of achieving a satisfying standard of living. The film brought to light how large media companies, especially conglomerates that own all production and distribution of media from start to finish, study and sell to teen youths because of their large quantity of â€Å"guilt money†, disposable income giving to youth by parents to keep them happy. They have become the most marketed group, which in turn turns the youth into adults that continue to seek happiness in consuming. The fear in this standard of living is that we start losing touch with our true values, and instead of looking towards family, community, ethnicity and religion as the creator of cultural forms, we are now being oriented as a society by the world of commodities. And with the advancement of technology, so has marketing research advanced, where we are being specifically being catered to with ads to continue this cycle of finding meaning and happiness through the purchase of goods and services. We will write a custom essay sample on Merchants of Cool or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Advertisers know that they cannot sell meaning and happiness, but they can illicit those feelings by advertising visions of what a â€Å"good life† should be through the selling of products, known as **image-based advertising**. Sut Jhally’s article, Image-Based Culture: Advertising and Popular Culture, explains how image-based advertising has been so integrated into our way of thought and consumption that it is difficult to pinpoint when our most cherished values became tied into consumer culture (p 201). Advertisements have taken up so much of our public space and discourse, and now even our private with the advancement of technology, that we are constantly being shown what the vision of happiness is, and what we must buy to achieve a satisfying standard of living. Juliet Schor’s article, The New Politics of Consumption: Why Americans Want So Much More Than They Need, breaks down the idea that Americans live in a constant state of **dis-ease**: worrying about the preoccupation with getting and spending (p 205). Not only is this disconcerting because it takes away from living in the moment, but it pushes us to live beyond our means. We aren’t happy because we do not emulate what we see as the â€Å"good life† because of the growing aspirational gap because of upscale emulation. We are never at ease where we stand economically and socially, and feel the pressures to keep up. And although this is a problem with the upper and middle class, it is a more dangerous problem for the lower class. The trickle effect of status symbol goods, such as state of the art phones, flat screen televisions, etc. , sets up those with limited resources and aspirations of living the â€Å"good life† by buying those goods for continual financial failure through consumption of expensive goods that is beyond their means. The film, The Merchants of Cool, aired in 2001, and the way that companies acquired information from the consumer was with â€Å"cool hunters†, marketing researchers who would research and interview to see what trends could be capitalized on. The analyzing was apparent, as opposed to now where consumers are being researched and targeted in ways that are more subtle, and now advertisers have the tools to more conspicuously sell us the â€Å"good life†. On the radio interview â€Å"How Companies are ‘Defining Your Worth’ Online†, Joseph Turrow discussed how marketers don’t even have to do much to gather information from us, they can now track our online movements using digital tracking like cookies. This information is gathered and sold to advertisers by data marketers, unbeknownst to us. Market research has evolved so much because of the growing digital world we live in. And advertisers are now able to subtly sell to us in a personally targeted way, instead of the blatant in your face banner ads that we would automatically close without even reading them. Although this is perfectly legal, the downfall falls on the consumer that is being researched and targeted. Our sense of consumption is insatiable when we are constantly being targeted, we lose a sense of privacy when we are constantly being watched, and, as Joseph Turrow also discussed, and we can also be targets of **digital social discrimination**. Digital social discrimination, which is the idea that companies can take digital information and make inferences of what kind of ads are suitable for the individual consumer, they target only certain ads, discounts, and such (2012). Advertisers then think of that individual only in a certain way, and may even target ads that may have negative connotations, such as getting out of debt ads, weight loss, and such. Consumers are being categorized, and because of the categories they are being targeted by certain ads, which perhaps sell a good that is not appropriate, and denied others because of assumptions being made by the online information gathered on that individual. This is why it is important to have some sort of regulatory system overseeing the structure and ownership of media. U. S. government plays only a small role in determining who owns the media, and only regulates it minimally, and the power of the U. S. media that uses the market research to produce products reaches us not just here in the United States, but also has a global impact. Because of the United States’ **cultural imperialism**, where American styles in fashion and food, as well as media far, dominate the global market, our versions of the â€Å"good life† are influenced on parts of the world, as discussed in Richard Campbell’s â€Å"Media Economics and the Global Marketplace†, (p 411). Our ‘cultural dumping’ of exporting U. S. media can influence other countries societal value systems, development of original local products, and abandon their own rituals to adopt American tastes. In reality, the power behind these large media researchers, marketers, producers, and distributors, who are often the owned by the same company, is astounding and influences not only our lives as an individual, but also has the potential to influence on a global level. They are able to gather information about individuals, sell it, and categorize as they see fit, leaving us with no sense of privacy, with the goal of selling us as many goods and services as possible until we reach the unattainable â€Å"good life†, which is a vision that they have carefully created. Until we, as consumers, are more aware of how much consumption has taken over our sense of self-worth and satisfaction and how little privacy we have in the new digital age, we will keep trying to buy the â€Å"good life†. ? Merchants of Cool free essay sample Does the restrictive structure of MTV, which limits exposure to a small percentage of artists who have significant corporate backing, mean that someone else is really making music choices for us? Is this kind of narrow control of music inevitable? Contrast the experience of a group like Limp Bizkit, which had corporate backing, to the careers of artists who have remained independent, like Ani DiFranco. (You may make a more modern comparison; just make sure to do your research! ) †¢ Is the mook (the stereotypically crude, adolescent male) real, or just a media construction? How about the midriff (the girl as sex symbol)? Do you know any mooks or midriffs? Do you think you or your friends are influenced by the MTV standard of cool? If so, how? Are there ways to be cool without copying media? How do the mook and midriff stereotypes relate to the corporate interests of the media outlets that perpetuate them (in other words, why these particular stereotypes and not some other stereotype)? †¢ Many media observers have claimed that programs like Beverly Hills 90210 or Dawsons Creek are popular because they are reflective of teen life. We will write a custom essay sample on Merchants of Cool or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page In what ways are shows like 90210 and Dawsons Creek reflective of how teenagers really live and in what ways are they distortions? Do these shows mirror the way you live? (Again, you may use more contemporary shows like Jersey Shore, Gossip Girl, True Blood, etc. ) †¢ Because they do so much research, media makers think they know a lot about you. Consider whether you agree with the following assertion from The Merchants of Cool: No teenager is going to be satisfied with a PG-13 rated horror film. They want to see blood and guts. Thats what they want to do.