Wood value chains

First, the market needs for a thermo formable TPO were characterized to define specific performance requirements. This was accomplished via review of published data and Voice of the Customer (VOC) interviews with key stakeholders in the custom thermoforming value chain including sheet extruders, custom thermoformers and original equipment manufacturers (OEM s). The output of this process was the need for development of polypropylene based thermo formable sheet that could replace fiber glass, metal, and wood. While many performance requirements are unique for each application, four specific performance requirements were common. 

As a result, in the Holocene a clear pattern of climate-induced variation in 5 C values of plant material and in bone collagen exists across Emope (Van Klinken et al. 1994). Figures 3.1 and 3.2 show that wood and collagen values are closely correlated, demonstrating that the trend is passed on in the food chain. The trend of enrichment from northwestern to southern Europe correlates very strongly with the climatic pattern across Europe the climatic isotopic variability is on the order of 2 to 4%o. 

Woods, 1964a) are compared in Table XIII. In all structures alanine, cystine, glycine, leucine, proline, serine, and valine, are present in considerable amounts, whereas compared with animal fibers the values for arginine, lysine, and tyrosine are small. In general the amino acids with acidic side chains greatly exceed those with basic side chains, but as with animal fibers the content of amide groups accounts almost quantitatively for this difference. 

The activation energy (E ) was calcnlated nsing the Arrhenius equation. Figure 8.17 shows the relationships between the reciprocal temperature of the tanS peaks shown in Fignre 8.15 and the logarithm of the measured frequencies. From the gradient of lines shown in Fignre 8.17, Ti s were calculated 512 kJ/mol for a dispersion and 59 kJ/mol for p dispersion. The value of the a dispersion was consistent with the main chain motion of polymers [64]. The E of the P dispersion was almost the same as that of the relaxation of water sorbed on wood, as estimated by the dielectric measurement [36]. 

Fats and oils are triesters of the alcohol glycerol. When they are hydrolyzed by saponification, the products are soaps, which are the salts of long-chain carboxylic acids (fatty acid salts). According to Roman legend, soap was discovered by washerwomen following a heavy rain on Mons Sapo ("Mount Soap"). An important sacrificial altar was located on the mountain. The rain mixed with the remains of previous animal sacrifices—wood ash and animal fat—at the base of the altar. Thus the three substances required to make soap accidentally came together— water, fat, and alkali (potassium carbonate and potassium hydroxide, called potash, leached from the wood ash). The soap mixture flowed down the mountain and into the Tiber River, where the washerwomen quickly realized its value. 

Table V was prepared from Figure 5. The critical PEG molecular weight is that molecular weight below which some penetration can occur into the substance. For untreated wood, it is about 3000. However, the meaning of this value must be interpreted with caution. According to the theory of gel permeation chromatography, the important single solute parameter is effective molar volume rather than molecular weight (9). The molar volume of a polymer depends on polymer-polymer and polymer-solvent interactions this is illustrated schematically in Figure 9 (36). The total chain lengths are the same for all the polymer systems, yet the configurations and bulkiness vary considerably.

In dialkyl di- and polysulfides, sulfur is the negative end of the dipole. The moment of a di-n-alkyl disulfide is approximately 2.00 D and of a trisulfide approximately 1.65 D, irrespective of the length of the carbon chain. In a tetrasulfide the moment is again higher thus, the alternating values 1.47, 2.00, 1.63, and 2.16 D, respectively, were obtained by Wood-row et al. (230) for the di-n-hexadecyl mono- through tetrasulfide series. 

The chain length of cellulose expressed in the number of AGU constituents (degree of polymerization, DP or n) varies with the origin and treatment of the raw material. In case of wood pulp, the values are typically between 300-1700. Cotton and other plant fibres have DP values in the 800-10000 range, depending on treatment. 

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