Solid resins

Poly(vinyl esters) used in paints and adhesives are available as homopolymers and copolymers in the form of solid resins, solutions, and dispersions. 

Poly(vinyl acetate) and vinyl acetate copolymers with crotonic acid, vinyl laurate, and dibutyl maleate are important solid resins some are available in solution. 

The neutral behavior of poly(vinyl acetate) allows the use of all conventional pigments. Poly(vinyl acetate) is highly compatible with ester-soluble nitrocellulose and improves the adhesion and lightfastness of the latter. Poly(vinyl acetate) can also be readily combined with phenolic resins, ketone resins, and colophony resins. 

Commercial products include Gelva (Monsanto), Mowilith (Clariant), Rhodopas (Rhone-Poulenc), Vinac (Air Products), Vinavil (Montedison), and Vinnapas (Wacker). 

Vinyl Acetate Copolymers. Copolymerization of vinyl acetate with other monomers allows specific improvement of certain properties. Copolymers generally exhibit a broader compatibility than the homopolymer. For example, softer, permanently flexible polymers with a lower water uptake and higher alkali resistance are obtained by polymerizing vinyl acetate with vinyl laurate. On account of their thermoplastic properties these copolymers are used in heat-sealable finishes on paper, cardboard, and aluminum foil. In cellulose nitrate lacquers they increase adhesion, lightfastness, and the body fullness of the paint film. They can also be used for priming coats and for stabilizing porous or absorbent substrates. 

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It is useful to measure the melting point of the solid resins. This can be done either by the ring and ball technique or by Durrans mercury method. In the latter method a known weight of resin is melted in a test tube of fixed dimensions. The resin is then cooled and it solidifies. A known weight of clean mercury is then poured on to the top of the resin and the whole assembly heated, at a fixed rate, until the resin melts and the mercury runs through the resin. The temperature at which this occurs is taken as the melting point. 

Solid resins have been prepared having a very closely controlled molecular weight distribution." These resins melt sharply to give low-viscosity liquids. It is possible to use larger amounts of filler with the resin with a consequent reduction in cost and coefficient of expansion, so that such resins are useful in casting operations. 

Density. Density is the mass of unit volume at a given temperature. For solid resins, density is evaluated according to DIN 51 757 at 20°C, whereas for liquid resins DIN 1995 U2 at 20°C is more appropriate. Densities of resins usually are in the range 0.88 to 1.15 g/cm. ... 

Fig. 2. RSST results on various resoles. The three bulk-charged resoles are at approximately 58% solids, 50% solids, and 40% solids. The programmed formaldehyde has no water charged except that contained in the 50% formaldehyde. The 50 and 58% solids resins reach self-heat rates of nearly 600°C/min. The 40% solids resin does not exceed 10 C/min. (Chart courtesy of Borden Chemical and Bill Burleigh.)...

This makes a mix with a viscosity of 5000-7000 centipoise. The total mix solids are 40% and the resin solids in the mix are 26%. A mix like this would be used on Douglas fir veneer at the rate of about 55 pounds per 1000 square feet of veneer surface (double glue line basis). The 43% solids resin would be used at about 500 cps viscosity. 

State at which resin exists before becoming a hard solid. Resin material has the consistency of a gelatin in this state initial jelly-like solid phase that develops during the formation of a resin from a liquid. 

Two-pack epoxies These were first patented in 1938 but were not in general production until 1947. They have been very widely used over the last decade. Produced from the by-products of the petroleum industry, the basic epoxy resins may be in the form of relatively low-viscosity liquid resins or they may be solid resins of increasing hardness. Both solid and liquid resins can then be reacted with a number of different curing agents. This means that almost any type of film and with any required properties can be made. 

A third method is to convert the structural foam cross-section to an equivalent I-beam section of solid resin material (Fig. 6-22). 

Plastrit or piastrotyl. Plastic expls patented in 1906 by C.E. Bichel. They were prepd by mixing 85—87p of TNT with liq and/or solid resins (such as copaiba, balsam, benzoin gum, styrax, turpentine, etc), and collodion cotton, with or without liq DNT Refs 1) Colver (1918), 249 2) PATR 2510... 

Petrick et al. [375] extracted up to 2000 dm3 of Atlantic Ocean waters using various solid resins. Down to 5 ng/dm were determined of chlorinated biphenyls, HCB, DDE, and polyaromatic hydrocarbons in samples taken at depths down to 4000 metres. 

Preparation First of all sodium hydroxide is added to formalin to make its pH about 8. To this urea is added. Now this mixture is refluxed for about 15 minutes. Then, it is acidified with formic acid and boiled for a further 5-20 minutes. The product is now neutralised with sodium hydroxide and evaporated under reduced pressure to get solid resin. 

Uses. The major applications of phenol are phenolic resins, Bisphenol A, and caprolactam. The reaction of phenol with formaldehyde gives liquid phenolic resins (used extensively as the adhesive in plywood) and solid resins (used as engineering plastics in electrical applications). In powder form, the phenolic resin can be molded easily and are completely nonconductive. These phenolic resins or plastics can be found in panel boards, switchgears, and telephone assemblies. The agitator in your washing machine is probably a phenolic resin. 

Amorphous material often produces tie chains that connect two or more different crystals. These tie chains increase the properties of the solid resin by forming a temporary three-dimensional crosslinked system. As the resin is melted in an extruder, the crystals and the tie chains are destroyed, and the polymer acts like a... 

The level of short-chain (SCB) and long-chain (LCB) branches control the solid resin density of a PE resin. For example, the level of SCB is controlled by the amount of alpha olefin comonomer incorporated into LLDPE resin as a pendant group. The random positioning of the pendant groups disrupts the crystailization process when the polymer is cooled from the molten state, causing the level of crystallinity to decrease with increasing amounts of alpha olefin comonomer. 

Cf compression ratio that should be used for a lower density feedstock resin Cpeiiets compression ratio used for a pellet feedstock specific heat of the solid resin diameter at the barrel wall local diameter at the screw core... 

The HIPS resin was extruded at screw speeds of 30, 60, and 90 rpm at barrel temperatures of 200, 220, and 240 °C for Zones 1, 2, and 3, respectively. The screw temperatures in Zone 3 as a function of time at the screw speeds are shown in Fig. 10.20. Because the RTDs were positioned within 1 mm of the screw root surface, they were influenced by the temperature of the material flowing in the channels. Prior to the experiment, the screw was allowed to come to a steady-state temperature without rotation. Next, the screw speed was slowly increased to a speed of 30 rpm. The time for the screw to reach a steady state after changing the screw speed to 30 rpm was found to be about 10 minutes. The temperature of the T12 and T13 locations decreased with the introduction of the resin. This was caused by the flow of cooler solid resin that conducted energy out from the screw and into the solids. At sensor positions downstream from T13, the screw temperature increased at a screw speed of 30 rpm, indicating that the resin was mostly molten in these locations. These data suggest that the solid bed extended to somewhere between 15.3 and 16.5 diameters, that is, between T13 and T14. When the screw speed was increased to 60 rpm, the T12 and T13 sensors decreased in temperature, the T14 sensor was essentially constant, and the T15, T16, and T17 sensor temperatures increased. These data are consistent with solids moving further downstream with the increase in screw speed. For this case, the end of the solids bed was likely just upstream of the T14 sensor. If the solid bed were beyond this location, the T14 temperature would have decreased. Likewise, if the solid bed ended further upstream of the T14 sensor, the temperature would have increased. When the screw speed was increased to 90 rpm, the T12, T13, and T14 temperatures decreased while the T15, T16, and T17 temperatures increased. As before, the solids bed was conveyed further downstream with the increase in screw speed. At a screw speed of 90 rpm, the solid bed likely ended between the T14 and T15 sensor positions, that is, between 16.5 and 17.8 diameters. These RTDs were influenced by the cooler solid material because they were positioned within 1 mm of the screw root surface. 

Thermoplastic structural foams with bulk densities not less than 50% of the solid resin densities are considered. Cellular morphology, uniform-density cell behaviour, the I-beam concept in designing, core-density profile and the role of the skin, mechanical properties, and ductile-brittle transitions are discussed. 63 refs. 

Phenyl-5-bromodifluoromethyl-l,2,4-oxadiazole was obtained in the system PhC(=NOH)NH2/BrCF2COOEt/Et3N/toluene ". 1,2,4-Oxadiazoles can be also successfully obtained from amidoximes linked to solid resin and (C1CH2C0)20 in 2-methoxyethyl ether (MeOCH2CH2)203 ... 

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