Revising Chemistry

POLYVINYL ALCOHOL (PVOH, PVA, or PVAL) is a water-soluble synthetic polymer. Polyvinyl alcohol has excellent film forming, emulsifying, and adhesive properties. It is also resistant to oil, grease andsolvent. It is odorless and nontoxic. It has high tensile strength and flexibility, as well as high oxygen and aroma barrier properties. However these properties are dependent on humidity, in other words, with higher humidity more water is absorbed. The water, which acts as a plasticiser, will then reduce its tensile strength, but increase its elongation and tear strength. PVA is fully degradable and is a quick dissolver. PVA has a melting point of 230°C and 180–190°C for the fully hydrolysed and partially hydrolysed grades, respectively. It decomposes rapidly above 200°C as it can undergo pyrolysisat high temperatures. PVA is an atactic material but exhibits crystallinity as the hydroxyl groups are small enough to fit into the lattice without disrupting it. ACETATE An acetate (IUPAC name: ethanoate) is either a salt or an ester of acetic acid. Its formula is written both as CH3CO2− and C2H3O2−. Chemists abbreviate acetate as OAc− and AcO−. Thus HOAc is the abbreviation for acetic acid, NaOAc for sodium acetate, and EtOAc for ethyl acetate.[1] Acetate is a common anion in biology. HYDROLYSIS Hydrolysis is a chemical reaction during which molecules of water (H2O) are split into hydrogen cations (H+) (conventionally referred to as protons) and hydroxideanions (OH−) in the process of a chemical mechanism.[1][2] It is the type of reaction that is used to break down certain polymers, especially those made by step-growth polymerization. Such polymer degradation is usually catalysed by either acid, e.g., concentrated sulfuric acid (H2SO4), or alkali, e.g., sodium hydroxide(NaOH) attack, often increasing with their strength or pH. Hydrolysis is a chemical process in which a certain molecule is split into two parts by the addition of a molecule of water. One fragment of the parent molecule gains a hydrogen ion (H+) from the additional water molecule. The other group collects the remaining hydroxyl group (OH−). The most common hydrolysis occurs when a salt of a weak acid or weak base (or both) is dissolved in water. Water autoionizes into negative hydroxyl ions and positive hydrogen ions. The salt breaks down into positive and negative ions. For example, sodium acetate dissociates in water into sodium and acetate ions. Sodium ions react very little with hydroxyl ions whereas acetate ions combine with hydrogen ions to produce neutral acetic acid, and the net result is a relative excess of hydroxyl ions, causing a basic solution. However, under normal conditions, only a few reactions between water and organic compounds occur. In general, strong acids or bases must be added in order to achieve hydrolysis where water has no effect. The acid or base is considered a catalyst. They are meant to speed up the reaction, but are recovered at the end of it.

Lahore Fashion Week

Dell expressed its commitment to creativity, design and style by joining the colorful activities and fashion ceremonies of the Lahore Fashion Week 2010. Dell's incredibly smart and high-performance notebooks were creatively featured on the catwalk by stunningly attired models during the high-end fashion extravaganza. Pakistan Fashion Week hit the ramps in Lahore from 16th to 19th of February 2010 as passion and creative energy drove all the prominent designers and models to participate in the events. More than 30 prominent Pakistani designers showcased a variety of casual and formal outfits, western wear, jackets and accessories. The Fashion Week 2010 was organized by the Pakistan Fashion Design Council (PFDC), which plans to make it a permanent fixture in the country's social and business calendars. Nubla Iftikhar, Marketing Manager for Dell Consumer and SMB said: 'Dell Consumer and Fashion are intricately woven together and therefore, Dell is proud to be associated with fashion-icon Munib Nawaz and the Lahore Fashion Week. Dell Consumer Notebooks are a form of self-expression. With a vivid color palette to express one's personal style, Dell Inspiron and Studio notebooks make a statement. It is a canvas for people to say a little something about themselves." Dell notebooks were showcased during a fashion show featuring the famous designer Munib Nawaz who presented his Men's wear Collection. The fashion week was a huge success giving a much-needed fillip to the local fashion design industry. Celebrities including Ali Zafar, Mommar Ranna, Iman Ali, Ather Shahzad also attended the event, with the glamorous fashion fraternity coming to support the fashion week, which culminated as a signature fashion event of the city. Following are some of pictures from Lahore Fashion Week. Courtesy: KoolMuzone ©

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Wal-Mart ..A scccess Story

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Wal-Mart de México said it achieved "solid" results in a "difficult" environment in 2009 with a lift in full-year profits.

For the 12 months to the end of December, Wal-Mart de México earned MXN16.8bn (US$1.29bn), a 15% increase on 2008.

Net sales rose 10.4% to reach MXN269.39bn, while EBITDA amounted to MEX26.91bn, a 13% increase on 2008.

Scot Rank, president and CEO, said: "I feel very proud of the results achieved in 2009. We achieved very solid results in a difficult economic environment and we improved our competitive position for the long term."

The company struck a deal to buy Walmart Centroamerica, a retailer with over 500 stores in five Central American markets, in December.

And in the fourth quarter, net income rose 17% to reach MEX5.74bn, while net sales amounted to MEX80bn, a 10% increase on 2008. EBITDA also rose 10% to reach MEX8.55bn.

Textile sector needs free access to global markets - Expert

Pakistani government should use diplomacy to penetrate world markets, opined Mr. Gohar Ejaz, Chairman of All-Pakistan Textile Mills Association (APTMA). Though the textile industry of Pakistan enjoys apex position across the world, it does not have free access to the international markets. Failure of negotiations on free-trade agreement with the US is unfortunate for the country, he added. It is difficult or country’s textile industry to thrive without acquiring firm stand in the international markets, while industrial expansion has a significant contribution in economic development of any country, said Mr. Ejaz.

Source: http://www.fibre2fashion.com/news/textile-news/newsdetails.aspx?news_id=79674

Chemistry in the Pulp and Paper Industry

21 - 22 December 2009

Sankt-Peterburg, Russia

The event format: lectures, presentations, Round Table, information, know-how and experience exchange.

Target audience: technical directors, chief engineers, chief technologists, chief experts in metrology, experts of central laboratories and technical inspection departments, experts of research laboratories of enterprises, technologists, management and experts of instrumentation and automation services, specialists of chemical laboratories, experts in water treatment, ecologists.

The following issues are suggested to be discussed at the Conference:

1. Main directions in development of chemical processes in the pulp and paper industry.

2. Wet End chemistry – new factors and appropriate estimation methods.

3. Secondary fiber deinking and bleaching with up-to-date chemicals.

4. Modern trends in surface treatment.

5. Some aspects of nanotechnologies in the pulp and paper industry.

6. Higher efficiency of chemical aids (with the use of dosing and control systems in particular).

7. Experience in introduction of new chemicals and technologies at pulp and paper mills.

The Registration Fee: 350 €.

Sustainable chemistry for the leather industry

Specialty chemicals group LANXESS is exhibiting a comprehensive range of products at the India International Leather Fair(IILF)in Chennai, India, on January 31 to February 2, 2010. Jürgen Hackenbroich, head of the Asia Pacific region in the Leather business unit, comments: “LANXESS continues to provide the Indian leather industry with premium products for so called ECO leather. Our technologies conserve resources and minimize both the amount of waste generated and the use of critical substances.” Levotan LB reinforces LANXESS’ role as one of the leading suppliers of softening polymer tanning materials, which are increasingly replacing between 55 to 75 percent of the fatliquor offer because of their technical and ecological advantages. New, versatile Levotan LB permits the cost-effective production of shoe and upholstery leather that are lighter, fluffier and softer than conventional fatliquored leather but nevertheless very durable. Levotan C-IN is a dispersing, lightfast anionic polymer retanning material. In combination with replacement syntans and vegetable and resin tanning materials it gives soft and tight leather. Levotan C-IN has good dispersing action and can be combined with vegetable tanning materials. It is highly suitable for milled leather, e.g. bag leather, shoe nappa and garment leather.Levotan C-IN helps to stabilize acrylic polymers and disperses them well, even at low pH values, thus keeping the grain smooth. Use of this product has been shown to considerably reduce the amount of wrinkling on different raw materials, thereby increasing the cutting yield. New Tanigan VR-IN combines all the advantages of modern chemistry with those of a vegetable tanning material. Because of its extremely well-balanced property profile, Tanigan VR-IN can be used to replace some or even all of the vegetable tanning materials in the retannage, depending upon the raw material quality. Compared with certain vegetable tanning materials, this sulfone-based synthetic organic tanning material has outstanding heat resistance and lightfastness properties and a pale, neutral color giving a brilliant dyeing. It also gives excellent filling and embossing characteristics. At IILF, LANXESS will launch its sulphon based retanning agents Tanigan BN-IN, Tanigan HO-IN, and Tanigan 3LN-IN. All these syntans contain low formaldehyde (HCHO): Tanigan BN-IN is a replacement tanning material for the tannage and retannage of very soft and full leather. Tanigan HO-IN, a versatile, lightfast and very good filling replacement syntan, is very suitable for the retannage of chrome leather and the tannage of chrome-free leather. It can be used as a sole tanning material or in combination. Tanigan 3LN-IN is a lightfast replacement tanning material with excellent resistance to heat yellowing for the tannage of white leather and for the retannage of chrome leather. It can also be used for colored nappa leather because of the good dyeing properties.

Instant Ice..what a chemistry

The Future of Fabrics

Spider Webs, Grass & Nanotubes – Behold the Brave New U.S. Textile Industry

It is tempting to think textile development hit its apex in 1873, when Jacob Davis and Levi Strauss invented denim blue jeans. What is more perfect than a worn pair of Levi’s?

It’s equally as easy to posit that advances in fabric – at least from a fashion-conscious consumer perspective – hit their nadir sometime in the late 1920s, when Wallace Carothers tinkered with what became polyester. Many of us remember the disastrous effects polyester had on 1970s shirts.

Tuff-n-Lite

The folks at Supreme Corp. say its Tuff-n-Lite fabric is as “soft as cotton, stronger than steel.” The North Carolina company blends super-strong synthetics such as Dyneema, Spectra and Twaron with its own proprietary ultra high molecular weight polyethylene fibers to produce cut-resistant fabric for military, police, safety and extreme sports apparel. On tap: stab- and fire-resistant material for soft body armor and other applications.

Visit www.tuffnlite.com

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Taggant, You’re It

Is that a taggant in your trousers? Tennessee-based Fiber Innovation Technology is embedding microscopic markers inside threads to protect against knock-offs. The markers or taggants identify the manufacturer, assuring consumers they’re getting the real deal. Some taggant pigments light up under laser wands. In the not too distant future, the company hopes to have taggants made of edible compounds that can be sprayed on agricultural products and pharmaceuticals. These micro identifiers would make it easier to isolate tainted products in the event of government-mandated recalls.

Visit www.fitfibers.com

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FrankenSpider

Spider silk is lighter, more elastic and – pound for pound – tougher than Kevlar. For decades, scientists have been trying to get arachnids to produce the stuff in bulk, much like silkworms have done for centuries. Unlike silkworms, however, spiders resist domestication and tend to eat each other when confined in groups. North Carolina-based EntoGenetics says it has discovered a way to infuse the spider’s gene into the silkworm, creating a creature that can spin strong, spider-like silk en mass without all the internecine insect violence. Possible uses: bullet-resistant vests, rope, parachutes, fine fabrics, medical sutures, ligament replacement and racing tires.

For more information, contact David Brigham, dbrigham@entogenetics.com

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No More Bed Bugs

Eczema. Psoriasis. Dermatitis. Poison ivy. The mere words can send some reaching for a shot of corticosteroid. North Carolina-based Precision Fabrics Group has unveiled a line of “therapeutic” bedding and other linens under the brand DermaTherapy for those with ultra-sensitive skin. According to one of the company’s 36 U.S. patents, its fabric also “provides a barrier to mite-induced allergen particles.” The Food and Drug Administration-approved line of bedding minimizes friction, reduces itching and is super soft. Take that, Egyptian cotton.

Visit www.dermatherapyfabrics.com

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Move Over, Hemp

Since at least 1989, U.S. researchers have been tinkering with kenaf, a fast-growing, high-yield fiber plant related to cotton and okra. Historically, the main uses of kenaf fiber have been rope, twine, course cloth (the Egyptians used it to make sails) and paper. Indeed, much of the domestic focus has been on using kenaf for eco-friendly “treeless” paper production. But 3F, yet another North Carolina company, is thinking bigger thoughts. It is developing a version of treated kenaf to make lighter, stronger precast concrete for bridges, buildings and the like. The lighter the precast concrete, the less fuel it takes to truck it to work sites. And the stronger the precast concrete, of course, the safer it is. The company also is turning kenaf into a bio-renewable replacement for fiberglass.

Visit www.3fonline.com

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Less Is More

Nanocomp Technologies of New Hampshire is making long non-woven textiles out of carbon nanotubes, hexagonally shaped arrangements of carbon atoms that have been rolled into, well, tubes. The company fabricates nanotubes into strong, lightweight electro-thermally conductive yarn and sheets. The goal: Make high efficiency super-capacitors for thermal-electric or heat-to-power generation. Nanotube materials also could dramatically reduce the weight and payload of electrical and structural systems in aircraft, making them more fuel efficient.

Visit www.nanocomptech.com

Dow Corning's Latest Silicone Solutions for the Textile Industry Go On Show in September

A leading supplier of innovative silicone solutions for the textile industry, will feature its new multifunctional softener for flame-retardant textiles, new impact protection material product line additions and silicone textile printing inks at the Northwest Apparel and Footwear Materials Show September 15-16. Visitors to Booth 224 will learn about Dow Corning DS-9000 Eco Repel , an eco-friendly multifunctional encapsulated silicone additive for technical textiles. Jointly developed with DEVAN Chemicals, this technology allows apparel manufacturers to increase softness and hydrophobicity on existing flame-retardant finishes without impacting flame retardancy. "Most current flame-retardant chemicals negatively impact the softness of the textile leading to very harsh fabrics, which then become uncomfortable-to-wear garments," said Jenny Geng, Dow Corning's global textiles marketing manager. "Moreover, the material type predominantly used in textile multifunctional treatment additives for flame retardancy contains fluorocarbon derivatives, which arouse increasing concerns of safety and environmental issues." According to Geng, the primary applications for Dow Corning DS-9000 Eco Repel include water-repellent silicone additive for textile flame-retardant finishes, softener for flame-retardant fabric finishing formulations, softener additive for fluorocarbon-containing formulations and use in mattress ticking, tenting, canvas, upholstery and protective clothing. In addition, Dow Corning will showcase two new product lines for its patented Dow Corning brand Active Protection System family of impact protection materials. The S-Range is based on 3D spacer textile technology and the TP-Range is based on thermoplastic technology. "The new products - seven in total - are flexible, breathable, washable and offer great impact protection," said Liz Mallen, Dow Corning Active Protection System program leader. "Overall, designers are getting far more choices." Unlike bulky hard-armor systems, Dow Corning Active Protection System silicone technologies are very comfortable to wear in terms of fit, freedom of movement and breathability. They can be incorporated directly into products to shield against high-energy impacts, delivering outstanding protection and, for apparel comfort. Supplied on rolls, Dow Corning Active Protection System products can easily be cut into desired shapes and built up in layers to maximize protection where needed. S-Range fabrics can be sewn into garments or pockets. Three-dimensional shapes can be created to protect areas such as knees, elbows or shoulders. The S-Range features three new products for varying levels of impact protection, including high-impact collisions, like those experienced in motorcycling or snowboarding; medium-energy collisions in sports, emergency services or medical applications; and low-level impacts like those from kicks or blows in sports such as soccer or martial arts. The TP-Range has four base products and allows for significant customization in regard to appearance, comfort and level of protection. The TP-Range is well suited for body armor applications in sports and sport accessories, and for use in protective cases and sleeves for sensitive equipment, and electronics such as laptop computers, cell phones and cameras. Other possible applications include personal protective equipment, footwear and luggage. Also at the show, the company will highlight Dow Corning brand Silicone Textile Printing Inks, which are durable, color-fast and suitable for tough-to-print, high-performance sports apparel. The inks offer high elongation and a soft, nonsticky handle and allow for innovative designs, including amber-look and water-droplet effects. With heightened consumer concern about the environment, silicone textile printing inks are an ideal solution because they contain no organotin, phthalate, formaldehyde, PVC or solvents. The 33rd semiannual Northwest Apparel and Footwear Materials Show will take place September 15-16, 2009, at the Oregon Convention Center in Portland, Oregon, USA. The event highlights natural and synthetic leathers, fabrics, prints, accessories, apparel and footwear components, and sewn products industry services. Dow Corning offers a comprehensive selection of proven silicon-based performance enhancers and process aids for textiles and is breaking new ground in the realm of eco-innovation. In addition to materials, the company provides supportive services and solutions tailored to the specific business and sustainability needs of the global textiles industry. Learn more about Dow Corning's full range of textile solutions.

50 COMMON INTERVIEW QUESTIONS AND ANSWERS

Review these typical interview questions and think about how you would answer them. Read the questions listed; you will also find some strategy suggestions with it. 

 1. Tell me about yourself? 
 Ans : The most often asked question in interviews. You need to have a short statement prepared in your mind. Be careful that it does not sound rehearsed. Limit it to work-related items unless instructed otherwise. Talk about things you have done and jobs you have held that relate to the position you are interviewing for. Start with the item farthest back and work up to the present. 
 2. Why did you leave your last job? 
 Ans: Stay positive regardless of the circumstances. Never refer to a majorproblem with management and never speak ill of supervisors, co-workers or the organization. If you do, you will be the one looking bad. Keep smiling and talk about leaving for a positive reason such as an opportunity, a chance to do something special or other forward-looking reasons. 


 3. What experience do you have in this field?
 Ans: Speak about specifics that relate to the position you are applying for. If you do not have specific experience, get as close as you can. 


 4. Do you consider yourself successful?
 Ans:You should always answer yes and briefly explain why. A good explanation is that you have set goals, and you have met some and are on track to achieve the others. 


 5. What do co-workers say about you? 
Ans: Be prepared with a quote or two from co-workers. Either a specific statement or a paraphrase will work. Jill Clark, a co-worker at Smith Company, always said I was the hardest workers she had ever known. It is as powerful as Jill having said it at the interview herself. 


 6. What do you know about this organization?
 This question is one reason to do some research on the organization before the interview. Find out where they have been and where they are going. What are the current issues and who are the major players? 


 7.. What have you done to improve your knowledge in the last year? Try to include improvement activities that relate to the job. A wide variety of activities can be mentioned as positive self-improvement. Have some good ones handy to mention. 

 8. Are you applying for other jobs? Be honest but do not spend a lot of time in this area. Keep the focuson this job and what you can do for this organization. Anything else is a distraction. 


 9. Why do you want to work for this organization? This may take some thought and certainly, should be based on the research you have done on the organization. Sincerity is extremely important here and will easily be sensed. Relate it to your long-term career goals. 


 10. Do you know anyone who works for us? Be aware of the policy on relatives working for the organization. This can affect your answer even though they asked about friends not relatives. Be careful to mention a friend only if they are well thought of. 


 11. What is your Expected Salary? A loaded question. A nasty little game that you will probably lose if you answer first. So, do not answer it. Instead, say something like, That's a tough question. Can you tell me the range for this position? In most cases, the interviewer, taken off guard, will tell you. If not, say that it can depend on the details of the job. Then give a wide range. 


 12. Are you a team player? You are, of course, a team player. Be sure to have examples ready. Specifics that show you often perform for the good of the team rather than for yourself are good evidence of your team attitude. Do not brag, just say it in a matter-of-fact tone. This is a key point.. 


 13. How long would you expect to work for us if hired? Specifics here are not good. Something like this should work: I'd like it to be a long time. Or As long as we both feel I'm doing a good job. 


 14. Have you ever had to fire anyone? How did you feel about that? This is serious. Do not make light of it or in any way seem like you like to fire people. At the same time, you will do it when it is the right thing to do. When it comes to the organization versus the individual who has created a harmful situation, you will protect the organization. Remember firing is not the same as layoff or reduction in force. 


 15. What is your philosophy towards work? The interviewer is not looking for a long or flowery dissertation here. Do you have strong feelings that the job gets done? Yes. That's the type of answer that works best here. Short and positive, showing a benefit to the organization.


 16. If you had enough money to retire right now, would you? Answer yes if you would. But since you need to work, this is the type of work you prefer. Do not say yes if you do not mean it. 


 17. Have you ever been asked to leave a position? If you have not, say no. If you have, be honest, brief and avoid saying negative things about the people or organization involved. 


 18. Explain how you would be an asset to this organization ? You should be anxious for this question. It gives you a chance to highlight your best points as they relate to the position being discussed. Give a little advance thought to this relationship. . 


 19. Why should we hire you? Point out how your assets meet what the organization needs. Do not mention any other candidates to make a comparison..

20. Tell me about a suggestion you have made ? Have a good one ready. Be sure and use a suggestion that was accepted and was then considered successful. One related to the type of work applied for is a real plus. 


 21. What irritates you about co-workers? This is a trap question. Think real hard but fail to come up with anything that irritates you. A short statement that you seem to get along with folks is great.