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Tensile Temperature Stage used to study the Influence of DMDBS on the Mechanical Properties of Polypropylene Films
Polypropylene (PP) is a common, commercial engineering plastic that is tough, flexible and can be manufactured via extrusion film casting (EFC). Most commercial PP is isotactic with all methyl groups orientated on the same side of the backbone of the polymer chain. This orientation of the methyl groups within the polymer relative to each other directly influences the ability of the polymer to form crystals.
DMDBS (dimethyl dibenzylidene sorbitol) is a butterfly shaped molecule that is used as a nucleating agent in the manufacture of PP via EFC. It forms crystalline nanofibres (approx 5nm diameter) when it precipitates out of a hot melt of isotactic PP (iPP). These nanofibres form a mesh. At cooler temperatures, iPP (α-form) crystals nucleate on the surface of these fibres.
Guruswamy Kumaraswamy and a group of scientists from the National Chemical Laboratory (NCL) of India have used a Linkam TST350 tensile testing temperature stage to look at the influence of this semi-crystalline morphology on the mechanical characteristics of the film.
Homopolymer iPP pellets were coated with DMDBS using a DMDBS solution in acetone. These pellets, with 0.2%, 0.4%, or 0.8% (by weight) DMDBS were extruded through a ThermoHaake PolyLab single screw extruder. This created a film of a constant thickness of 0.45mm as the film was taken up on chill rolls (10°C). To achieve six different draw ratios, the speed of the chill rolls was varied.
These films were tested using the Linkam TST350 stage. The stage is built to maintain perfect uniform vertical and horizontal alignment during testing. Temperature control and accuracy is second to none, with a range from -196 to 350°C with 0.1°C control and up to 60°C/min heating rate.
It was observed that at TDIE=200°C voids form within the 0.8% DMDBS film during extrusion. This, the scientists hypothesised, was the reason why the 0.8% film exhibiting a decrease in yield stress and modulus values compared to neat iPP film and the 0.2% & 0.4% films. The 0.2% and 0.4% DMDBS PP films exhibit a ≈50% increase in modulus and yield strength compared to neat PP. This is observed to be higher in the transverse direction. More information can be found in the paper ‘the influence of DMDBS on the morphology and mechanical properties of polypropylene cast films’ by K. Sreenivas, Harshawardham V.Pol, and Guruswamy Kumaraswamy.
MICROSCOPY MORE INFO. 583
OFweek’s 2012 Best LED Service Supplier Award in China Announced
Ocean Optics has recently been recognised with an ‘OFweek 2012 Best LED Service Supplier Award’ by China’s high technology portal OFweek photonics news.
Since its entry into the Chinese market, Ocean Optics has contributed to the growth of China’s LED industry. The inventor of the world’s first miniature spectrometer provides photometry and colorimetry solutions to the complete LED manufacturing chain. Established in 2007, Ocean Optics Asia supports the company’s distributors and customers in the Pacific Rim with a team of application, sales and software engineers.
Ocean Optics was chosen for the OFweek honour from a pool of 200 nominated companies selected by the editors of OFweek. A total of 38 companies were recognised with awards in 10 categories, chosen by a panel of LED experts as well as online voting by LED professionals. Winners were announced during the 9th LED Pioneering Technology & Marketing Seminar at the 2012 Best LED Enterprises & Products Award Ceremony organised by OFweek photonics news.
Dr Sun Ling, Vice President of Ocean Optics Asia said, “We feel so proud to be conferred the Best LED Service Supplier Award by OFweek. This honour encourages our expert team to strive towards ever-higher standards and deliver even better services to our customers in China and Asia Pacific.”
“China’s LED industry has enjoyed fast growth with ever higher demand for testing speed and diversity. This makes it imperative for us to work more closely with system integrators and end users,” Dr Sun added.
Ocean Optics’ solutions for quantifying light meet a number of parameter measurement and quality monitoring challenges on factory production lines. Its products cover the complete LED manufacturing chain – from epitaxial wafer and wafer material probing, to chip sorting, to the testing of finished LEDs – accurately and efficiently measuring and controlling wavelength, thinness, reflectance, transmittance, colour temperature, and colour purity.
SPECTROSCOPY MORE INFO. 584
Innovative Solutions for Clean and Sterile Processing
Since 1990, Steritech have been the sole agents for Fedegari and Stilmas in the GMP pharmaceutical sector in the UK and Ireland. Recently, the Company have also started to represent Fedegari Autoklaven’s range of laboratory autoclaves and Stilmas’ sister company Olsa who manufacture a large range of equipment for solids, liquids and semi-solid processing.
Fedegari Autoklaven has been manufacturing their range of compact autoclaves geared towards the laboratory market since the 1980s. These units are built to the strictest GLP standards and are used not only within the microbiology and analysis laboratories sector but also in research institutes, pharmaceuticals, food industry and biomedical applications. Like their famous industrial big brothers, the Fedegari laboratory range of autoclaves is at the cutting edge of steriliser technology. Steritech offer the most innovative, reliable and validatable range of sterilisers on the market and all are available at a very competitive price.
Olsa have been producing equipment for solids, liquids and semi-solids processing since 1947. Primarily Olsa provide equipment for manufacture within the pharmaceutical and cosmetic sectors as well as high-end food and chemical industries. Olsa compliment their larger scale manufacturing equipment with a range of smaller units geared towards laboratory development and scale up activities. Olsa design, manufacture and support their equipment at the very highest level. Their customers are those that understand that investing in the right equipment more than pays back over its lifetime. This is achieved principally by minimising the time to validation, decreased breakdowns, increased production and operative lifetime.
LAB PRODUCTS MORE INFO. 585
Ceram is pleased to announce that it has launched a new blog, dedicated to materials.
Populated by Ceram’s team of experts, the blog will be offer an opportunity to get involved in some lively debate about materials, from the latest innovations and new regulations to what’s happening in the industry.
Mandy Rymill, Marketing Communications Manager, at Ceram said: “We’re hoping that the blog will be very interactive with lots of interesting and, at some times, controversial, exchanges. Our bloggers are all experts in their field but they’re not afraid to be challenged and to discuss different points of view.
“I’m sure that both our existing and new customers, as well as our staff, will find the blog informative and that we can generate some really good discussions around materials, to the benefit of all.
“It’s sure to appeal to anyone interested in materials and will cover industries as diverse as healthcare and construction through to ceramics and aerospace.”
To view the blog and join in the debate visit
www.ceram.com/blog. LAB PRODUCTS MORE INFO. 586
Launch of Materials Blog
LABMATE UK & IRELAND - JANUARY 2013
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