polymer_technology

I hope the world goes more on this way: " Use Biodegradable materials in Architecture and also Civil Engineering ". Thank you very much Aldrich Company.

( Ammar Ghasemian Azizi, ammar5ghasemian@yahoo.com , 00989386878531 )

من که از وب سایت زیر کلی استفاده کردم و مطالب جالبی (بخصوص تو رشته تخصصیم پلیمر) رو دانلود کردم. در سایت زیر راجع به هر مطلبی که دوست داشتید میتونید سرچ و دانلود کنید. حتی میتونید مطالبی رو که خودتون دارید رو برای استفاده دیگران آپلود کنید. در کل من که کلی استفاده کردم امیدوارم برای شما هم مفید باشه.

http://www.scribd.com/

 http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Introduction/introduction.htm

“Green” polymer additives based on renewable resources

maybe you enjoy too. You can download it at the below link.

www.ienica.net/greentech/vanHaveren.ppt

Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber.

Depending on its processing and thermal history, polyethylene terephthalate may exist both as an amorphous (transparent) and as a semi-crystalline polymer. The semicrystalline material might appear transparent (particle size < 500 nm) or opaque and white (particle size up to a few microns) depending on its crystal structure and particle size. Its monomer (bis-β-hydroxyterephthalate) can be synthesized by the esterification reaction between terephthalic acid and ethylene glycol with water as a byproduct, or by transesterification reaction between ethylene glycol and dimethyl terephthalate with methanol as a byproduct. Polymerization is through a polycondensation reaction of the monomers (done immediately after esterification/transesterification) with water as the byproduct.

The majority of the world's PET production is for synthetic fibers (in excess of 60%) with bottle production accounting for around 30% of global demand. In discussing textile applications, PET is generally referred to as simply "polyester" while "PET" is used most often to refer to packaging applications. The polyester industry makes up about 18% of world polymer production and is third after polyethylene (PE) and polypropylene (PP).

PET consists of polymerized units of the monomer ethylene terephthalate, with repeating C₁₀H₈O₄ units. PET is commonly recycled, and has the number "1" as its recycling symbol.

Reference of this text is Wikipedia

A large number of application areas using inherently conductive polymers have been developed and tested. Each is based on properties that are specific to these materials. Due to the recent development of several air-stable highly conductive polymers, and the fast entry of these products into the marketplace, several applications have already been possible, and numerous others are going to be easily realized.

The unique properties of inherently conductive polymers stem from (i) the possibility of fine-tuning the conductivity by adjusting the amount of dopant incorporated within the polymer, (ii) doping/undoping reversibility, and (iii) the optical absorption characteristics in the UV, visible and near infrared as well as its electromagnetic absorption characteristics.

Several polymers have been tested and proved to work in a variety of applications including batteries, capacitors, smart windows, light emitting diodes, transistors, photovoltaics, microlithography, corrosion control, conductive adhesives and inks, static dissipation, EMI shielding, radar/microwave absorption, direct plating, electrostatic powder coating, clean room applications, sensors, and drug delivery systems.The status of commercial products and devices will be given during the seminar.Examples of some polymers are shown below:

The following is a short list. Any suggestions for additional books for listing in this section are welcome.

Conducting Polymers, Fundamentals and Applications: A practical Approach, P. Chandrasekhar Editor, Kluwer Academic Publishers, Hingham, MA (kluwer@wkap.com), ISBN 0-7923-8564-0, 1999, 760 pages, $168

Conductive Polymers and Plastics in Industrial Applications, L. Rupprecht Editor, A publication of the Society of Plastics Engineers (#9902), ISBN 1-884207-77-4, 1999, 290 pages, $135 (SPE member) or $160 (non member), Plastics Design Library, 13 Eaton Ave., Norwich, NY 13815 (Tel/Fax: 607-337-5080/337-5090).

Handbook of Conducting Polymers, 2nd edition, T. Skotheim, R.L. Elsenbaumer and J. R. Reynolds Editors, Marcel Dekker, New York, 1998, 1097 pages, ISBN 0-8247-0050-3, www.dekker.com

Intrinsically Conducting Polymers: An Emerging Technology, M. Aldissi Editor, 1993, 223 pages, Kluwer Academic Publishers, Hingham, MA (kluwer@wkap.com), ISBN 0-7923-2456-0

Proceedings of the International Conference on Synthetic Metals, held every two years and typically published by Elsevier as a special issue in the Journal "Synthetic Metals". The last meeting was held in Austria, July 16-21, 2000.

A book on electroactive polymers that focuses on actuator applications and edited by Y. Bar-Cohen has a chapter (Ch. 7) on conductive polymers. An outline can be found at http://ndeaa.jpl.nasa.gov/nasa-nde/yosi/yosi-books.htm

Reference of this text is: http://www.conductivepolymers.com/

Ammar Ghasemian Azizi , عمار قاسمیان عزیزی

در پستی که در مرداد ماه سال 87 نوشته بودم حسابی از مشکل محیط زیستی تو کشور گله کرده بودم و نگرانی خودم رو ابراز کردم تا شاید روزی کسی این نوشته نه چندان قابل رو بخونه و دلش به حال این طبیعت بسوزه و به خاطر خدا و خلق خدا کاری بکنه. ولی افسوس !!!

امروز یک گزارش محیط زیستی تو سایت "فرارو" خوندم که در تاریخ 20 آذر 1389 به نقل از یک فعال محیط زیست به نام آقای محمد درویش، مطرح کرده بود:

"""""""""" محمد درویش یکی از فعالان محیط زیست است که وبلاگ مهار بیابان‌زایی از 5 سال پیش به این سو می‌نویسد. وی در پست اخیر خود به رتبه ایران در آلوده‌سازی محیط زیست اشاره کرده است:

همان طور که در این نقشه می‌بینید، 10 کشور نخست جهان که بیشترین آلودگی را در محیط زیست کره زمین ایجاد می‌کنند، عبارتند از:
1- چین
2- آمریکا
3- روسیه
4- هند
5- ژاپن
6- آلمان
7- کانادا
8- انگلستان
9- ایران
10- کره جنوبی
این بررسی توسط یک نهاد پژوهشی محیط زیستی در آلمان موسوم به Germanwatch تهیه و انتشار یافته است. 

نکته جالب در این رتبه‌بندی آن است که ایران در شرایطی به عنوان یکی از 10 کشور آلوده کننده جهان مطرح شده است که از نظر تولید ناخالص ملی و قدرت اقتصادی به هیچ وجه در سطح 9 کشور دیگر نیست. 

به نظر می‌رسد باید حرف آن نماینده مجلس را قبول کنیم که چندی پیش گفته بود: 70 میلیون ایرانی به اندازه یک میلیارد نفر از مردم جهان، انرژی مصرف می‌کنند! 

البته شخص آقای محمدی‌زاده هم از شنیدن این خبر نباید تعجب کند! زیرا او شاید نخستین فردی بود که در سال گذشته و حتا پیش از انتشار نتایج این بررسی توسط آلمان‌ها، آن را افشا کرد و خودش را یکپا "ویکی زیست" معرفی کرد! نکرد؟ """""""""""""

Silicone

Silicones are used for a lot of things. They can be elastomers and lubricating oils. The caulking in your bathroom that seals the edges of the bathtub is probably made of a silicone. Silicones are also used to make the heat resistant tiles on the bottom of the space shuttle. Back on earth, silicones are used to make hair conditioners that don't cause buildup.

Silicones are -->inorganic polymers because there are no carbon atoms in the backbone chain. (To chemists, "organic" means "it has carbon in it" and "inorganic" means it doesn't.)

The backbone is a chain of alternating silicon and oxygen atoms. "R" stands for whatever molecules might be attached to the backbone.

When different organic groups of atoms attach to the backbone, different kinds of silicones are formed. For example, if -CH₃ (methyl) groups attach to the silicon atoms, the polymer is called polydimethylsiloxane. It's the most common silicone.

Silicones make good elastomers because the backbone chain is very flexible. The bonds between a silicon atom and the two oxygen atoms attached to it are very flexible. The angle formed by these bonds can open and close like a scissors without much trouble. This makes the whole backbone chain flexible.

Polydimethylsiloxane does something really strange when you mix it with boric acid, or B(OH)₃. The mixture is soft and pliable, and you can mold it into any shape easily with your fingers. But it's also very bouncy. What's more, push it gently and it gives way, but hit it hard with a hammer and it cracks! Strangely, if you spread it over newspaper, and pull it away, it gets printed with a mirror image of the newspaper text. No industrial use was ever found for this wonder material, but tons of it have been sold as a toy called "Silly Putty."

Reference of this text is: http://www.pslc.ws/