...powdered chitin from crab shells. The nanocomposite could have applications in devices that need a high light transmittance, such as flat panel displays. Scientists have previously used cellulose from plants and chitin to strengthen materials, giving biologically-inspired nanocomposites. If natural nanofibres are dispersed widely enough in a transparent polymer matrix, they can strengthen the polymer and the resulting nanocomposite material will retain its transparency. Work on optically transparent polymers containing cellulose nanofibres shows they have a low axial thermal expansion coefficient, meaning their size does not vary with temperature, making them ideal for use in flexible flat panel displays and solar cells. Muhammad Iftekhar Shams and co-workers from Kyoto University took a whole crab and treated it with hydrochloric acid, sodium hydroxide and ethanol to remove the minerals, proteins, fats and pigments, respectively. This gave a chitin-only crab shell, which they immersed in an acrylic resin monomer. Following polymerisation, they obtained an entirely transparent crab shell. The shell retained its shape and detail, right down to the creature's eyes. Preparing the transparent crab shell: (a) original shell, (b) shell after removal of matrix substances and (c) transparent crab shell after immersion in acrylic resin | 'Encouraged by the transparent crab, we undertook the development of optically transparent composites based on crab-shell chitin fragments in powder...
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...Study of the different flow patterns in the melting section of a co-rotating twin-screw extruder. Polymer Engineering and Science - February 1, 2003 Guo Yichong Word count: 5666. citation details [pic] INTRODUCTION Twin-screw extrusion (TSE) Involves solid conveying, melting, mixing, venting and homogenizing, and the extrusion process affects the quality of polymer products considerably. Co-rotating twin-screw extruders are mainly used for compounding, and they are commonly of modular design, which means the screw elements can be configured to reach optimal conditions. Conveying elements and kneading blocks are the two common types of screw elements, which are designed based on conjugation or kinematics principles. Investigations of co-rotating TSE have covered many aspects. Recent literature shows that some investigations first obtained data from experiments, and then obtained the regularity about the TSE process according to the experimental results (1-3). Such studies usually had some practicality, for instance, to clarify the temperature profiles, pressure drop, etc. Other investigations simulated the process with physical and mathematical methods, and then verified the simulation results with experimental data (4-9). They often emphasized the theoretical significance. Several experimental methods have been used in TSE melting studies. Todd (10) conducted his experiments using a clam-shell barrel. Bawiskar and White (11) and Potente and Melish (12) adopted the screw extraction...
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...online 26 January 2008 Abstract Lack of degradability and the closing of landfill sites as well as growing water and land pollution problems have led to concern about plastics. With the excessive use of plastics and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. The interest in environmental issues is growing and there are increasing demands to develop material which do not burden the environment significantly. Biodegradation is necessary for water-soluble or water-immiscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires understanding of the interactions between materials and microorganisms and the biochemical changes involved. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. This paper reviews the current research on the biodegradation of biodegradable and also the conventional...
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...Polycaprolactam Student Name: Syed Ali Shahid, ID Number # 20595181; email: sashahid@uwaterloo.ca 1. Introduction and Applications Polycaprolactam or PA 6 is a synthetic polyamide commonly recognized by its trade name Nylon 6. Polyamides or nylons are polymers characterized by the amide group –CONH-as recurring part of their polymer chain. The original nylon was first made in a laboratory in DuPont, USA in 1935 by Wallace Carothers. It was recognized as the first semicrsytalline polymer, the first engineering thermoplastic, and the first synthetic fiber .Amongst various variants of polyamide, polycaprolactam is particularly different in that it is made from only 1 kind of monomer- caprolactam which will be discussed in this paper in further detail from various aspects. Schalak while working on polyamides in IG Fabraen laboratory synthesized polycaprolactam through ring opening polymerization of caprolactom. He heated caprrolactam in a flask to about 250oC with about 5-10% water which hydrolyzed a few percent of the caprolactam to aminocaproic acid. The NH2 group of the aminocaproic acid acted as ring opening initiator for polycaprolactam followed by a polycondensation reaction of the NH2 and COOH group of the low molecular weight product of the ring opening polymerization reaction resulting in a high molecular weight product-Polycaprolactam. The key properties of polycaprolactam that have made them suitable for a variety of industrial applications are toughness, fatigue...
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...A PAPER ON “SELF-HEALING POLYMER TECHNOLOGY” [pic] SUBMITTED BY: Sreeja Gadhiraju, Naga vaishnavi.A, III/IV Mech, Sri Sivani Institute Of Technology. sreeja.btech@gmail.com INDEX |Topic |Page No. | | | | |ABSTRACT |1 | |introduction |2 | |INTRINSIC SELF-HEALING |2-3 | |EXTRINSIC SELF-HEALING |4-5 | |HEALING MECHANISM | 5-7 | |APPLICATION |7-8 | |PROBLEM AND CHALLENGES |9 | |CONCLUSION ...
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...Review Paper Inulin - a versatile polysaccharide with multiple pharmaceutical and food chemical uses. Thomas Barclaya, Milena Ginic-Markovica, Peter Cooperb,c, Nikolai Petrovskyc,d a Flinders University, Adelaide, Australia 5042 Cancer Research Laboratory, ANU Medical School at the Canberra Hospital, Australian National University, Canberra, Australia 2605 c Vaxine Pty Ltd, Flinders Medical Centre, Adelaide Australia 5042 d Department of Endocrinology, Flinders Medical Centre, Adelaide, Australia 5042 b Received: 27 August 2010 Accepted: 10 October 2010 ABSTRACT á-D-glucopyranosyl-[â-D-fructofuranosyl](n-1)-D-fructofuranoside, commonly referred to as inulin, is a natural plant-derived polysaccharide with a diverse range of food and pharmaceutical applications. It is used by the food industry as a soluble dietary fibre and fat or sugar replacement, and in the pharmaceutical industry as a stabiliser and excipient. It can also be used as a precursor in the synthesis of a wide range of compounds. New uses for inulin are constantly being discovered, with recent research into its use for slow-release drug delivery. Inulin, when in a particulate form, possesses anti-cancer and immune enhancing properties. Given its increasing importance to industry, this review explains how inulin's unique physico-chemical properties bestow it with many useful pharmaceutical applications. KEY WORDS: Inulin, polysaccharide, fructose, excipient, vaccine, adjuvant INTRODUCTION ...
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...Natural and butyl rubbers have the advantages like low cost, very good over molding properties, reusable and very easily recyclable scrap [9,10]. Butyl rubber based thermoplastic elastomers have excellent adhesion with other thermoplastics hence it is still used to date for many over molding applications [11]. A list of common thermoplastic elastomers used in modern world is given in Table 1. 1.2.2. Amorphous thermoplastics They are usually transparent and have diffused melting point. The molecules are arranged randomly and ] ] _ to crystalline polymers. Upon curing they shrink less as compared to crystalline thermoplastics [3,4]. Examples are polycarbonate (PC), polymethylmethacrylate (PMMA), polystyrene (PS), polyphenylene oxide (PPO), acrylonitrile butadiene styrene (ABS) [1]. 1.2.3. Semi-crystalline thermoplastics Semi-crystalline polymers plastics have combined properties of crystalline polymers and amorphous polymers. Examples are polyester Polybutylene terephtalate (PBT) and Polyamide (Nylon 6, Nylon 66). 1.3. Thermoplastic elastomers Thermoplastic elastomers are one of the most ver_ ] Thermoplastic elastomeric materials...
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...Due Care RELIANCE INDUSTRIES LIMITED PET DIVISION DUE CARE FOR USING RELPET – PET RESIN Contents 1. Introduction 1.1 What is PET? 1.2 PET Manufacturing Process 1.3 Characteristics of PET 2. 3. RELPET Grades and their applications Receipt, Handling and Discharge Procedures for RELPET Packages 3.1 Receipt of Material 3.2 Unloading Procedures 3.3 Handling Procedures 3.4 Discharging Procedures for 25 kg and 1 T bag 3.5 Importance of Clean Storage 3.6 Reporting Procedure in case of receipt of damaged bags 4. Processing Guide 4.1 Introduction 4.2 Drying 4.3 Temperature & Other Settings 4.4 Mould Sweating 4.5 Use of Regrind 5. 6. 7. 8. 9. Trouble Shooting for Injection Moulding of Preforms and Stretch Blowing of Bottles Inputs from Customers in case of Complaint. Storage and Transportation of Finished Bottles PET Recycling Due Care Audit 10. Annexures : Annexure - I Annexure - II Annexure - III Annexure - IV Annexure - V Annexure - VI Annexure - VII Annexure - VIII Annexure - IX Annexure - X Annexure - XI Procedure for Transit related damages Procedure for Un-loading of 1 Ton bag. Discharge Procedure for 1 Ton bag Procedure for Start-up of machine Guidelines for supply of PET Bottles to Pharma / food industry Drying of PET Process Parameters for Single-Stage machine Process Parameters for Two-Stage machine Mould Sweat Protector (MSP) Trouble-Shooting guide. Contact information & Disclaimer Page 2 of 40 DUE CARE FOR USING RELPET – PET RESIN 1. Introduction: The purpose...
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...and Dielectric thermal analysis (DETA) are the techniques used for studying the structure-properties relationships of the composites. The experimental results show that the matrices studied and their specific properties have a great impact O. A. Al-Hartomy : A. A. Al-Ghamdi Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia O. A. Al-Hartomy Department of Physics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia N. Dishovsky (*) : M. Mihaylov : M. Ivanov Department of Polymer Engineering, University of Chemical Technology and Metallurgy, 8 Kl. Ohridski Blvd., 1756, Sofia, Bulgaria e-mail: dishov@uctm.edu F. El-Tantawy Department of Physics, Faculty of Science, Suez Canal University, Ismailia, Egypt upon both the dynamic mechanical and dielectric parameters of...
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...Science and Engineering 2012 ABSTRACT Four tri-block copolymers composed of poly(L-lactide)-poly(caprolactone-co-L-lactide)-poly(L-Lactide) (PLLA-PCLLA-PLLA), with disrupted ends were characterised according to individual’s mechanical and thermal properties. The tri-block copolymers consist of amorphous PCLLA middle block, at constant composition of CL and LLA being 60% and 40% respectively. The end blocks consist of either a semi-crystalline PLLA or various compositions of P(LLA-DLLA). Factors such as high overall crystallinity and effective crosslinking of arms led to the high modulus values of polymers. A 16-week degradation study was done to investigate degradation behaviour. The number average molar mass, mass loss, water uptake and the changes in mechanical and thermal properties were investigated at each designated time points. Experiments revealed that the polymers degraded via bulk degradation. The 16-weeks period only showed the initial stage of degradation whereby...
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...for their insolubility in water. (1 mark) (iii) During a practical session, Ms. Chan demonstrated to the students that when water and oil were added to a test tube, the two liquids formed two separate layers. She then added a solution of phospholipids to the mixture of water and oil. With justification, predict where the phospholipids would have dissolved. (3 marks) (b) Figure 2.3 shows part of a DNA molecule. [pic] Figure 2.3 (i) Name the TWO components that make up the part of the DNA molecule labeled as P. (2 marks) (ii) Name the bond labeled as Q. (1 mark) iii) Describe how DNA monomers, nucleotides, join to form a polymer. (2 marks) (c) David learnt that when an egg was fried, the clear egg white surrounding the yolk became solid, white and opaque. He claimed that peptide bonds...
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...Introduction: Many of today’s greatest inventions have been created by “accident” , meaning that these products were created in the midst of a scientist trying to make something else. Three of these products, two of which were staples during many of our childhoods, are things we could not imagine a time without them. The “accidents” we will be focusing on are nylon (yes, the material panty hose are made of), Silly Putty®, and the bouncy ball. Nylon Nylon, a synthetic polymer fiber, was invented by Wallace Hume Carothers at the E.I. DuPont de Nemours Company in Delaware in 1934. Nylon stockings became a huge hit as soon as they were released during World War II after a public supply cut-off. Although Carothers receives recognition for the creation of the polymer, another DuPont employee may the actual inventor. Julian Hill worked with Carothers, and had spent time developing a process where a long fiber with a silky texture could be created of carbon polymers. Carothers may have had a psychological issue, and committed suicide in 1937. The company accredited the invention of nylon to him in honor of him. Nylon was created entirely from petrochemicals unlike previous artificial fabrics like rayon and acetate, which were plant based. Nylon was designed as a synthetic silk for women’s stockings. The material was intended to be less expensive while adding qualities such as strength and insulation. Nylon is not only used in stockings, but is also used in an enormous amount...
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...At room temperature is a colorless gas with an odor similar to gasoline. It is an alkene used to manufacture rubber by addition polymerization. It has two C-C double bonds in its structure which allows the compound to form a wide variety of polymers including ABS. This compound is a toxic gas listed as a human carcinogen. Figure 2. Representation of 1.3-butadiene (mw: 54.09 g/mol) Styrene: A colorless to yellowish liquid that produce polystyrene by homopolymerization. Styrene is a derivative of benzene and could be found in small quantities in plants and foods. It is slightly soluble in water and very soluble in ethanol, acetone and carbon disulfide. Its rate of polymerization is low at room temperature but increases at higher temperatures. Figure 3....
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...and synchrotron radiation. The Centre for Biomaterial Development of the Institute of Polymer Research of the GKSS in Teltow offers a PhD Student Position - Code-No. 2009/PB 10 in the fields of Polymer Science and Pharmaceutical Technology for activities in a DFG funded project on new applications of shape-memory polymers. The position will be for three years. You will investigate new capabilities of shape-memory polymers as drug carriers in the field of Pharmaceutical Technology. You will be responsible for the benchwork including polymer synthesis and comprehensive polymer characterization as well as analysis of the properties such as the thermomechanical behaviour of polymer-based drug carriers. Moreover, depending on your personal interest, there will be the opportunity to extent your personal expertise and to participate in the preparation of drug carriers or the biomaterial characterization in cell studies after training by experts in the respective fields. Furthermore, you will actively participate in the publication of the results and the preparation of patent applications. You have a strong background in both polymer and organic chemistry with a Diploma or Master in chemistry with a focus on Polymer Sciences or likewise. You possess practical experience in polymer synthesis and characterization. Advantageously, but not a precondition, would be experiences with shape-memory polymers. Applicants with a strong interest in...
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...Example Research Paper on Polymer Chemistry: Introduction Polymerization refers to a chemical reaction that results in bonding of two monomers to form a polymer (Tarle, 435). A polymer molecule is made up of hundreds, thousands, or even millions of atoms joined together to form a chain with an extended length at least an order of magnitude greater than its thickness (Peacock & Calhoun, 2006). Polymers have variations of molecular weight (length), branching, steric configuration, interconnections and chemical defects (Tarle, 435). A polymer is made up of many elements. One can consider a polymer as a thread with every link of this string forming a fundamental unit which is in turn made of hydrogen, carbon, silicon and oxygen(Tarle, 435). They are mostly made up of hydrocarbons though other elements such as Sulphur, nitrogen and chlorine may also be found(Carraher & Charles, 2). The molecules are held together by covalent bonds that are branched, linear, or networked to form the polymeric material (Carraher & Charles, 2). While most polymers have carbon as their backbone, others have silicon as the main element holding the polymer (Carraher & Charles, 2). . The history of polymerization The science of polymerisation began way back in the 19th century where alumina-silica glass and phosphoric acid was widely applied to fill dentures (Carraher & Charles, 2). . However, the compounds had very poor mechanical properties and high solubility. This meant that they...
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