PET polyester fibres are produced commonly in round crosssection, but fibres of special cross-section are now available from a number of manufacturers. PET polyester fibres are thermoplastic, and lend themselves well to physical modificationc associated with this property. Crimped and textured yarns of all familiar types are available. Production: Polyethylene terephthalate is made by the condensation of terephthalic acid, or a derivative such as dimethyl terephthalate, with ethylene glycol. Reaction a.
These control the release rate of the drug from the patches. These are prepared by dispersing the drug in polymeric base solution. There are some polymers used in preparation of Transdermal patches: Natural polymers: such as, cellulose derivatives, Zein, Gelatin, Shellac, Waxes, Proteins, Gums and their derivatives, Natural rubber, Starch etc. Synthetic Elastomers: e.g. polybutadiene, hydrin rubber, polyisobutylene, silicon rubber, nitrile, acrylonitrile, neoprene, butyl rubber etc.
(n.d.). Retrieved April 17, 2016, from http://www.slideshare.net/ ripestone_ho/polymers-and-their-properties INTERESTING facts about Isotactic Polypropylene Polypropylene is a versatile thermoplastic polymer. It can be moulded into different shapes and sizes and hence, can be put to many uses (material used to make chairs, containers, tools etc.) It is hard but flexible. (semi-rigid) It is lightweight!
Phenols can be used as disinfectants, medical products and etc. Phenols are readily absorbed following inhalation, ingestion or skin contact, and it can be found in human breast milk (Wolff, 2007). It is produce naturally and synthesized as a manufactured chemical. It is an constituent of coal tar, decomposing organic material, human and animal wastes, and as a compound that is commonly found in many non-foods and foods (Xhang, 2008). Biopolymers are polymers that biodegrade the action of microorganisms, heat and moisture.
Jacques Yves Cousteau writes, “Water and air, the two essential fluids on which all life depends, have become global garbage cans” (Cousteau 1). Recycling is an easy way to take care of our planet. Everyone should recycle because it saves energy and protects animal’s natural habitats. Recycling saves natural energy. Recycling items like aluminum cans, glass, and paper keeps us from depending on the process of making these items new.
R-DNA technology uses palindromic sequences and leads to the production of sticky and blunt ends.The DNA sequences used in the construction of recombinant DNA molecules can originate from any species. For example, plant DNA may be joined to bacterial DNA, or human DNA may be joined with fungal DNA. In addition, DNA sequences that do not occur anywhere in nature may be created by the chemical synthesis of DNA, and incorporated into recombinant molecules. Using recombinant DNA technology and synthetic DNA, literally any DNA sequence may be created and introduced into any of a very wide range of living organisms.Proteins that can result from the expression of recombinant DNA within living cells are termed recombinant proteins. When recombinant DNA encoding a protein is introduced into a host organism,
Investigating how the composition and the structure affect the parent material of polymers: We are using Plastics widely everywhere and so many types of plastics we have. The additives change the structure and the composition of the polymer. Plastic is a polymer we use plastics everywhere soft plastic is used as covers and hard plastic is used as tables in our daily life without plastics we can’t live. Additives are needed for plastics because additives make plastics safer, tougher, colourful and cleaner plastics can be made. They reduce manufacturing cost will be reduced and the product lives longer.
It 's true that for many of us diapers are not a critical aspect of daily life. Even parents of young children only address dithering needs for a few short years. Interestingly, the impact of the disposable diaper however affects each of us and is a long-lasting trouble. It is currently estimated that 10,000 tons of disposable diapers are tossed into landfills each day. Each of these 10,000 diapers take up to 500 years to decompose, at best.
Aliphatic polyesters Aliphatic polyesters are the most widely biodegradable polymers that used in environmental and biomedical fields. In general, these polymers are synthesized via chemical polycondensation reactions using catalyst such as titanium oxides (Gross R.A et.al. 2010; Yang et al., 2012).A wide range of aliphatic polyesters can be designed by using various reactants and changing the synthesis conditions to meet specific requirements such as hydrophobicity, crystallinity, solubility, degradability, glass transition temperature, melting temperature and so on (Clarinval A-N., 2005). 1.1.2. Aliphatic polyesters synthesis Polyesters were historically the first family of synthetic condensation polymers and were investigated as part of Carothers’ pioneering
In fact, only 48 percent of our waste is recycled. In other words, the majority is left to the landfills. And hopefully, it would decompose after being buried for like 5 decades or even more. However, according to the waste statistics from the Hong Kong Environmental Protection Department, the solid waste sent to landfill per day is around 9,000 tons. And with such speed of waste produced, the maximum capacity of the landfills would be eventually