یکی از مسائلی که واقعا برای بنده به عنوان شخصی که در صنایع پتروشیمی در واحد های پلیمری کار کرده و همچنین با صنایع پایین دستی وابسته به پلیمر آشنایی کامل دارم، مطرح است این است که چرا توسعه صنایع تکمیلی اینچنینی، نباید از وظایف وزارت نفت باشد و از زیر مجموعه های وزارت صنعت، معدن و تجارت است. اگر ما بخواهیم در زمینه استقلال از وابستگی فروش نفت خام و همچنین محصولات پتروشیمی با ارزش افزوده کم، قدم برداریم باید خود وزارت نفت را به عنوان ثروتمندترین وزارتخانه کشور، به عنوان متولی جدی و قدرتمند توسعه صنایع تکمیلی بسیج کنیم. ای کاش میشد این حرف ها رو در جلسه ای جدی و ویژه مطرح کرد و ای کاش بعد از مطرح شدن پیگیری و اجرا میشد.
+ نوشته شده در جمعه بیست و هشتم تیر 1392ساعت 8:36  توسط Ammar Ghasemian Azizi
As a research chemist at an IBM laboratory, Jeannette M. Garcia spends her days mixing and heating chemicals in pursuit of stronger and more easily recyclable plastics. Recently she followed a simple formula that required mixing three components in a beaker. Somehow she missed a step, leaving out a chemical. She returned to find her beaker filled with a hard white plastic that had even frozen the stirrer.
Dr. Garcia tried grinding the mystery material, to no avail. Then she took a hammer to the beaker to free it.
That laboratory error has led to the discovery of a new family of materials that are unusually strong and light, exhibit “self-healing” properties and can be easily reformed to make products recyclable.
The materials — two new types of synthetic polymers — could have transportation uses. Because of their recyclability, they also could have an impact on consumer products, as well as on the industrial packaging for microelectronics components.
The findings were reported on Thursday in the journal Science by a research team at IBM’s Almaden Research Laboratory in San Jose, Calif.
There has been an explosion of new polymer materials in recent years, but most of them are variants of existing synthetic classes that are characterized by long chains of simpler molecules connected through chemical bonds. The materials are today ubiquitous in modern life, found in everything from paints and contact lenses to garments and batteries.
“They are just pervasively used materials,” said James L. Hedrick, an advanced organic materials scientist at IBM in San Jose. “This is the polymer age.”
The IBM scientists say that this is the first distinctly new family that has been discovered in several decades.
They said they had not yet named the new family, which they have code-named “Titan” and “Hydro.” The materials are not yet ready for commercial use, but the scientists said they had already begun working with several universities on composite applications that could have a significant impact on manufacturing and fabrication in the fields of transportation, aerospace and microelectronics.
The materials are known as thermosets because they are formed using a heating process. Their strength comes from their three-dimensional network of chemical bonds. The polymers have the rigidity of bones, one of the strongest biological materials, and can be made as much as 50 percent stronger by blending them in composite form with materials like carbon nanotubes. They also tend to perform better than other types of polymers under high temperatures.
IBM has invested heavily in new computational chemistry technologies that rely on supercomputers. The researchers were able to build a computer model of the new material, characterizing it in two distinct types, one that was “soft and gooey” and the other extremely rigid.
“There is this conventional wisdom out there that the main classes of polymer materials have all been discovered,” said Bob Allen, a senior manager for Chemistry and Advanced Materials Research at the laboratory. “But with this approach that we’ve taken with heavy doses of computational time, as well as hard-core laboratory synthesis, we’ve come up with a new one.”
The IBM finding evokes the discovery of Teflon, said Timothy E. Long, a chemistry professor at Virginia Tech. “Serendipity is the mother of invention.”
In 1938, while looking for alternative refrigerants, Roy Plunkett, a DuPont chemist, inadvertently polymerized tetrafluorethylene, accidentally creating one of the most slippery materials.
In a perspective essay accompanying the research article in Science, Dr. Long argued that the new materials represented a significant advance in efforts to make consumer goods more easily recyclable, particularly electronics, which have become a major waste problem.
“Thermosets are designed to be exceptionally stable in terms of temperature and mechanical properties; they are not designed to be reversible,” he said. “To think about materials that have all of these properties, and which are also recyclable, is an advance.”
+ نوشته شده در سه شنبه چهارم شهریور 1393ساعت 9:42  توسط Ammar Ghasemian Azizi
Talc is a highly functional additive that enhances key properties of numerous resins. In addition to being a cost-effective filler, talc can effectively provide antiblocking, reinforcement, and improved barrier properties. During polymer processing, talc, as the softest mineral, minimizes equipment wear. It also decreases mold shrinkage, and improves end product machining.
Uses For Talc In Plastics
Plastics exhibit increased stiffness, reduced mold shrinkage, improved heat stability and lower material costs when filled with the appropriately sized talc. Impact strength can be maintained when the particle size is carefully controlled to a 1 to 2 micron, ultrafine median particle size while maintaining a minimum top size. In addition to size, talc particle shape and particle aspect ratio can be used to further optimize these properties. Talc-filled polypropylene automotive parts, whether they are interior, exterior or under the hood applications, have the required stiffness, strength and other mechanical properties. Talc-filled polypropylene works well in appliance applications requiring load-bearing properties at ambient and elevated temperatures.
Thermoplastic elastomers, whether they be homopolymer, copolymer or TPO resin systems, benefit from the addition of the appropriately sized, high aspect ratio talc. Talc filled olefins also exhibit ductile fracture while the base resin fractures tend to be brittle.
As an example, talc with an aspect ratio of 10 to 1 when melt compounded with a homopolymer will provide a 250 percent increase in flexural modulus.
In polyethylene film applications, talc is an effective, low abrasion antiblock. Polyester gel coat barrier properties are improved with the addition of fine ground, platy talc. Talc also functions well as a nucleating agent during melt compounding.
Some of the key plastic application areas for talc are:
LLDPE, LDPE, & PP Films
BMC, Polyester Gel Coats
Nucleation agent in
Specialty Minerals Talcs in Plastics
A variety of talcs are manufactured by Specialty Minerals to suit the formulator’s need to optimize the properties of a particular polymer system for a particular application. FlexTalc® talc products are ideal for the high performance automotive TPOs for interior and exterior applications. FlexTalc 610, an ultrafine 1 micron talc, provides the best performance. These high brightness products provide increased stiffness, i.e., improve the flexural modulus, improve the heat deflection temperature and the tensile strength of the base polymer. For the same high mechanical performance, but where high brightness is not essential, the Barretts, Montana, MicroTuff® AG talc series offers a cost-effective alternative. When mechanical demands are less, but brightness is still critical, the Mt. Vernon, Indiana, MicroTuff® 9100 talc series are recommended.
Specialty Minerals was the developer of talc-based antiblock additives for polyethylene films. ABT® and Polybloc® talcs are best suited for general purpose blown films. When the highest clarity is required, the Optibloc® family of products should be used.
For nucleation, use an ultrafine ground talc such as UltraTalc® 609 talc. This and slightly coarser products act as nucleation centers, increasing the temperature at which the polymer crystallizes and solidifies, thereby reducing cycle time and increasing productivity.
از تیر ماه سال 1387 که این وبلاگ رو راه اندازی کردم، این همه تلاش کردم که در راستای توسعه دانش علم پلیمر و همچنین کامپاندهای پلیمری قدم مثبتی برداشته باشم ولی حیف که کسی این تلاش رو ستایش نمیکنه هیچ، بلکه هستند دوستانی که این عمل رو زیر سوال میبرند. این همه تلاش میکنم برای سربلندی ایران عزیز و در دسترس گذاشتن مطالب علمی برای جویندگان علم پلیمر بدون هیچ چشم داشتی و وقتی پاسخش میشه این فقط افسوس میخورم. خوب من که این مطالب رو خودم خوندم و بهشون اشراف کامل دارم و این یعنی وقتی اینجا جمع آوری میکنم واسه خدمت رسانی هستش و نه بیشتر.
+ نوشته شده در یکشنبه هفدهم شهریور 1392ساعت 5:50  توسط Ammar Ghasemian Azizi
The types of glass fiber most commonly used are mainly E-glass
(alumino-borosilicate glass with less than 1% w/w alkali oxides, mainly
used for glass-reinforced plastics), but also A-glass (alkali-lime glass
with little or no boron oxide), E-CR-glass (alumino-lime silicate with
less than 1% w/w alkali oxides, has high acid resistance), C-glass
(alkali-lime glass with high boron oxide content, used for example for
glass staple fibers), D-glass (borosilicate glass with low dielectric
constant), R-glass (alumino silicate glass without MgO and CaO with high
mechanical requirements), and S-glass (alumino silicate glass without
CaO but with high MgO content with high tensile strength).
Reference of this text is Wikipedia free encyclopedia.
+ نوشته شده در سه شنبه بیست و نهم مرداد 1392ساعت 8:26  توسط Ammar Ghasemian Azizi
The effects of polypropylene grafted with maleic anhydride (PP-g-MA) and epoxy resin (ER) on the interfacial interaction of the long glass fiber reinforced PP composites were investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and mechanical properties. The experimental results demonstrate that PP-g-MA and ER could effectively improve interfacial interaction between the PP and LGF. Based on SEM, good interfacial adhesion between PP and LGF in PP/ PP-g-MA/ER/LGF composite was observed. DSC results showed that the existence of PP-g-MA or ER caused crystallization temperature shift to low temperature, and melting temperature shift to high temperature. All results in this paper were consistent, and showed the good interaction between PP and LGF, which were proved by the mechanical properties of the composites
is(dnyr)A unit of fineness for rayon, nylon, and silk fibers, based on a standard mass per length of 1 gram per 9,000 meters of yarn.
دنیر واحد اندازهگیری دانسیته جرمی الیاف میباشد که بهصورت جرم در واحد گرم بر ۹۰۰۰ متر تعریف میشود.
واحد اندازه گیری نرمی الیاف است(و یا ضخامت الیاف) و به وزن 9000 متر لیف بر حسب گرم گفته می شود. هرچه عدد دنیر بیشتر شود لیف ضخیمتر و غیرنرم تر است.
+ نوشته شده در یکشنبه نهم تیر 1392ساعت 18:29  توسط Ammar Ghasemian Azizi
برای سرمایه گذاری در صنعت پلیمر و پتروشیمی بدون مشاور علمی هیچ گاه اقدام نکنید زیرا خطر ورشکستگی بسیار بالا است . برای مشاوره می توانید با بنده به شماره 09123862365 و یا 09386878531 تماس بگیرید . بدانید که یکی از پر سود ترین سرمایه گذاریها سرمایه گذاری در صنعت نفت است . ( عمار قاسمیان عزیزی )