Blend foams

Some foam products are subjected to up to 10 major impacts in their lives, therefore a foam may need to be selected so that the performance is still adequate. Products, subjected to hundreds of thousands of impacts as in running shoe midsoles, were dealt with under fatigue. It appears that the higher density HDPE (419) and PP foams loose a significant amount of their protection after several impacts, but nevertheless it may be possible to use sufficient foam thickness to provide the required protection. If low density EVA foams are used, the impact energy densities are much lower, as the majority of the resistance is from compressing the cell gas. Ankrah and co-workers (33) performed multiple impacts on LDPE/ESI blend foams, and found... 

Brookfield, Ct., 2002, Session II, p.47-54, 27cm, 012 SEQUENTIAL REACTIVE BLENDING/ FOAMING OF PET IN EXTRUSION EQUIPMENT... 

Foams 2000 Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p. 102-7 NEW PRODUCTS MADE FROM ETHYLENE-STYRENE INTERPOLYMER/LDPE BLEND FOAMS FOR VARIOUS APPLICATIONS Ramesh N S Sealed Air Corp. 

The static and dynamic mechanical properties, creep recovery behaviour, thermal expansion and thermal conductivity of low-density foams made of blends of LDPE and EVA were studied as a function of the EVA content of the blends. These properties were compared with those of a foam made from a blend of EVA and ethylene-propylene rubber. A knowledge of the way in which the EVA content affects the behaviour of these blend foam materials is fundamental to obtaining a wide range of polyolefin foams, with similar density, suitable for different applications. 9 refs. 

Keywords Blend Foam Morphology Compatibilization Multiphase Nanostructured... 

Fig. 10 Foam structure of PPE/SAN blends (foaming time 10 s, temperature 180°C)...

Arfoam. [Aquaness] Blend foaming agents to remove water and Ued sol-i during drilling operations. 

Dodifoam Brands. [Hoechst AG] Surfactant blends foaming agents for drilling. 

PP/PE, EPR, EPDM, SBS, ionomers, EVAc, blends foamed with isopentane Fudge, 1987... 

PC/PET, or PETG, EEA, r extrusion-blended, foamed, then injection Avakian and Jodice, 1986... 

The hole fraction, h, computed from the PVT data, was found to correlate with the static (thermodynamic equilibrium) and dynamic properties (e.g., flow of polymers) [Utracki, 1986 2005], as well as their blends, foamed compositions [Utracki and Simha, 2001a,b], composites, and nanocomposites (see Chapter 14). 

It is automated by a four-axis bridge robot, which can be set in motion just by pressing a few buttons. Graphical software is used to enter the coordinates and the four-axis design allows efficient spraying of three-dimensional molds up to 9 m (29.5 ft) wide. A further development incorporates a mechanically blended foam unit, to automate foam applications. 

Using compressed gas instead of chemicals to foam polyester resins can reduce control problems and heat reactions. Mechanically blended foam processing systems use a non-reacting additive pre-mixed into the resin... 

D. KohUioff, M. Ohshima, Influence of polyethylene disperse domain on cell morphology of polystyrene-based blend foams. J. Cell. Plast. 50, 241-261 (2014)... 

This enhanced ability to prodnce and keep nanoporons structures was further studied in different low-MAM amonnt blends, from 5 to 20 wt% [101]. First, it was noticed that the addition of the PBA block indnced an increase of the CO2 sorption of PMMA/ MAM blends directly related to the PBA amonnt, confirming the higher C02-philicity of the PBA block. They fonnd that 90/10 PMMA/MAM blends foamed at RT and pressures between 10 and 30MPa show weU-deflned nanoporous foams with pore sizes from 150 to 190mn, porosities between 40% and 55%, and pore nucleation densities of... 

HCFCs were used in the first instance to replace CFCs in a transitional phase and, imtil the end of 2002, HCFC-141b was still the number one physical blowing agent in North America. The London Amendment to Montreal allows the temporary use of HCECs to continue in some countries imtil 2040. US companies are still allowed to use HCFCs for thermal insulation foams and to import blended foams containing HCFC-141b until 2010. European usage can also continue for the manufacture of exported foam products to certain countries until the end of 2009. 

Yao et al. [72] investigated PLA/PMMA blend foams at 75/25, 50/50, and 25/75 wt% compositions for medical applications such as cell growth. Factors such as solubility and carbon dioxide diffusivity played an important role in these applications. Gas solubility was studied using a microelectronic balance. Henry s law constant for CO2 in the blends increased with an increase in the PLA content of the blends. Foam morphologies of the blends as compared to neat polymers were investigated with respect to the effects of pressure and temperature. PLA/PMMA blends improved the foam morphologies compared to the neat polymers. More details about these blends can be obtained in Chapter 17. 

Yuan et al. [120] has reported the research on PLA/PBAT blend foam. Maleic anhydride is used to enhance compatibility between PLA and PBAT. The compatibilization mechanism of maleic anhydride (MAH) is that MAH enhances intermolecular force by forming hydrogen bond between grafted MAH and polymer backbone. Grafting MAH onto PLA and PBAT is performed by reactive extrusion, which can improve the interfacial adhesion between PBAT and PLA matrix. In order to increase the maleicing reaction activity, a free radical initiator, 2, 5-dimethyl-2, 5-di-(/er/-butylperoxy) hexane (LlOl), can be used. 

When a few years ago high-melt-strength PP became conunercially available, several efforts were made to produce 100% noncrossUnked PP foams [18,33]. Moreover, attempts have also been conducted to produce crosslinked PP foams. On the one hand, using a PP random copolymer with low ethylene content, electron irradiation, and multifimctional nomomers as crosslinking promoter, PP foams and PP/LLDPE blend foams have been produced and characterized [34]. On the other hand, PP films and sheets for use in automotive applications have also been manufactured, using organosilane crosslinking of selected PP copolymers [35]. The Zotefoams company [36],... 

Uses Dispersant detergent wetting agent for textiles coemulsifier for various oils emulsion stabilizer foam builder in detergent blends foam booster/sfabilizer in pharmaceuticals, shampoos Trade Names Teric CME3 PEG-6 cocamide MEA Ionic Nature Nonionic... 

Although the bilayer representation is a very over simplified model for describing polymer blends since the domain size of the dispersive phase is only in the range of micron, it gives us some invaluable information about bubble nucleation and growth in the early stage of blend foaming process. 

A simple PS/PMMA bilayer representation is examined for better understanding of PS/PMMA blend foaming process. Visual observation of batch foaming of... 

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