High barrier performance

LCPs are highly effective barrier materials, as noted previously in section 3.3. When used with less costly plastics, LCP barrier layers provide cost-effective multilayer films, trays, and containers with high barrier performance. 

In order to achieve the goals of making more efficient use of the information that is produced and of planning and performing better experiments, chemoinformatics will have to be more integrated into the daily work processes of the chemist, and into the work of the bench chemist. Certainly, many chemists still have to overcome high barriers to using the computer for assistance in the solution of their daily scientific problems. 

Speas, C. A., Closure Performance Requirements for High Barrier Plastics... 

In the lamination process, films of different materials are bonded using heat and/ or biodegradable adhesives [23, 34]. A metallized film (e.g., from PLA) with high barrier and stiffness can also be laminated on a Ecoflex /starch or Ecovio compound with good welding performance to produce e.g., a stand pouch for detergents. 

In 2002, Musaev and coworkers performed the first theoretical investigation of the mechanism with the aid of density functional theory calculations [26]. They first studied the mechanism of cycloisomerization in the absence of a tungsten catalyst, as shown in Scheme 4.14. The D FT calculations showed that the exo-cycloisomerization of 4-pentyn-l-ol via a concerted transition state leading to a five-membered-ring exo product had a high barrier (52.0 kcalmol ) (path a of Scheme 4.14). The pathways leading to a six-membered-ring endo product have also been calculated (paths b and c... 

Applications for sulphur concretes fall into two broad categories utility uses and high corrosion performance uses. Utility applications refer to those for which PC concrete performance is relatively satisfactory, such as parking bumpers, precast curb and gutter, paving slabs and highway median barriers. In these applications in-place economics rather than performance is the criterion that will determine commercial use. As a general rule of thumb, when sulphur and Portland cement are the same price, sulphur concrete should be economically competitive for these applications. 

The solution of Eq. 1 requires specification of boundary conditions (BCs) and additional equation(s) that describe the sorption reaction. The assumptions reflected in these choices strongly influence the process of extrapolating barrier performance from laboratory column data. Furthermore, as discussed below, there are significant differences in the treatment of these choices between low- and high-permeability systems. 

A high barrier in the conduction band due to unfavorable band line-up or interface charge at the buffer/TCO junction may impede the majority carrier transport at this nn-junction. There are no indications for a significant barrier in standard cells but it has been made responsible for the poor performance of certain cells with alternative Cd-free buffer layers [9]. 

In order to determine the ethylene insertion starting from the chelated complexes, the slow growth MD simulations were performed, with the distance between the a-carbon of the chain and an olefin carbon chosen as a reaction coordinate.. The activation barriers obtained from the simulations are presented in Table 4-1. The results clearly show that in each case the barriers are substantially lower for the Ni-than for the Pd-catalyst. For all the systems, the ethylene insertion reactions starting from the most stable chelate structures 12, 13, and 14 have very high barriers (38-53 kcal/mol and 32 11 kcal/mol, for Pd and Ni, respectively). These values are much higher than the standard ethylene insertion barriers into the metal-alkyl bond (AE = 16.8 kcal/mol and 14.2 kcal/mol for Ni and Pd, respectively). These high barriers demonstrate that the ethylene insertion definitely cannot proceed from the most stable ethylene-chelate structure. 

FKuR also introduced Biograde 200C in 2005, an unfilled cellulose blend with high stiffness and transparency for cast film and injection moulding. The material can also be blow moulded into bottles and thermoformed into cups and trays. Injection moulded Biograde 200C exhibits properties comparable to polystyrene, but with the addition of barrier performance comparable to PLA. It consists of 100% renewable resources, but does not contain starch. 

In this model,110 it was assumed that all C 2H bonds perform thermally activated rotational jumps within energy landscapes on the surface of a cone. Specifically, six basins were supposed to be separated by six energy barriers at positions 0, 60,..., 300° around the axis of the cone. For each cone, the barriers were drawn anew from the distribution of activation energies determined for TOL in DS.12,19 Further, it was assumed that all positions on the surface of the cone, except for the barriers, have the same energy, i.e., a random-barrier model was considered. The thermally activated jumps lead to a random new position in one of the two neighboring basins. This means that several back-and-forth jumps occur over relatively low energy barriers until relatively high barriers are crossed. In other words, many... 

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