Glutinous starches

Old nat. adhesives old (historic) natural adhesives, e.g. starch, glutin, casein adhesives. 

There are two kinds glutinous rice starch is parched and then ground into a powder, which is called Quick Starch glutinous rice starch is steamed or further, pounded into a cake, parched and ground into a powder,... 

Manufacture. (1) Parched glutinous rice starch Glutinous rice is... 

UF, urea-formaldehyde resin MUF, melamine fortified UF resin MF/MUF, melamine and melamine-urea resins (MF resins are only used mixed/coreacted with UF resins MUPF, melamine-urea-phenol-formaldehyde resin PF/PUF, phenol and phenol-urea-formaldehyde resin (P)RF, resoreinol-(phenol-)formaldehyde resin PMDI, polymeric methylenediisocyanate PVAc, polyvinylacetate adhesive old nat.adhesives, old (historic) natural adhesives (e.g., starch, glutin, casein adhesives) nat.adhesives, natural adhesives (e.g., tannins, lignins, carbohydrates) inorg.adhesives, inorganic adhesives (e.g., cement, gypsum) activation activation constituents of wood to function as adhesives (i.e., lignin). 

Glutin comp. wheat starch hydrolysis Kirchhoff, 1814 ... 

Spallanzani in 1783 (Sumner and Somers, 1953), the enzymatic hydrolysis of taimin was described by Scheele in 1786 (Tauber, 1949), in 1814 Kirchhoff observed that a glutinous component of wheat is capable of converting starch to sugar and dextrin, and Vogel showed in 1817 that an iirfusion of oats would produce a fermentable sugar from milk (Roberts et a/., 1995). 

The gluing experiments were done with commercially available starch, proteins (casein, glutin) and tannins of mimosa Acacia spp.), Pinus radiatay and quebracho (Schinopsis spp.) and with tannins extracted from the bark of spruce (Picea abies) and common pine (Pinus sylvestris). The extractions were carried out with water or organic solvents under alkali and/or sulphite conditions on a laboratory scale aiming at optimization of yield and polyphenolic extract content. After extraction, the solutions were concentrated under reduced pressure and freeze dried. One pine bark extract was modified with phenol. A summary of the tannin extracts and their properties is given in Table I. 

Table V. Mechanical Properties of 19-mm Particleboard1 Bonded with Mixtures of Nonemulsifiable Diisocyanate (PMDI) and Starch or Glutin...

There are two ways to hold the composition of Senko-Hanabi one is a dry process twisting a piece of Japanese paper tape 23 mm wide and 200 mm long containing about 0.09 of the composition at one end the other is a wet process where sticks made of rush or straw are dipped into a liquid mixture to a desired depth, withdrawn and dried in the sun. The liquid mixture is made by adding glutinous rice starch and water to the composition. 

Aluminium reacts with potassium chlorate or perchlorate in presence of moisture to generate hydrogen gas. The reaction proceeds very slowly at room temperature, but is accelerated over 85 C. This reaction is not so violent as that of aluminium and a nitrate. Aluminium does not react with ammonium perchlorate or starch, e.g. glutinous rice starch. 

Note Al=fine flake aluminium, GRS= glutinous rice starch, AA=acetic acid, BA=boric acid, GA=gura arabic... 

The symbol OO in Table 13 shows the composition did not decompose when heated for a long time. It must be noted that wet aluminium powder decomposes without other chemicals when it is heated for a long time. Glutinous rice starch does not react with aluminium. 

V/hen a small amount of water is added to the glutinous rice starch and kneaded, it becomes like rice cake and quite cohesive. But when we add a large amount of water to the starch and boil it for long time, the cohesive power of the starch decreases this shows that the amylopectin changes to amylose. 

The cohesive power of glutinous rice starch is very strong this is seen clearly by comparing this starch with others like dextrine. Add ten times as much water to glutinous rice starch and stir well. Test it between the fingers, and it is clear how far more cohesive it is than a dextrine solution which is prepared in the same way. 

This cohesive nature of glutinous rice starch is quite important especially for preparing round stars, because the essential point of the process lies in that the composition must be pasted in a wet state on the core using as little paste as possible Accordingly a paste which has a strong cohesive power satisfies the requirement well. For this reason glutinous rice starch is quite superior for manufacturing round stars. 

In other words, it is not too much to say that the Japanese round stars are widely developed only by the presence of the glutinous rice starch. 

However the cohesive power of the paste of glutinous rice starch generally changes as the time passes when it is mixed with chemicals or compositions. For example, an experiment in the summer season is set out in Table 16. 

Here 20 cc of distilled water was added to mixtures of 2 g of glutinous rice starch and 20 g of other chemicals. The mixture were stirred well and the viscosities were observed at definite time intervals. 

Table 16. The influence of clicmicals upon the viscosity of soluble glutinous rice starch...

The decrease in the viscosity caused by sodium oxalate or black powder, which are the most powerful, was more precisely observed. In the first one or two hours it looks as though there is an increase in the viscosity, and then the viscosity slowly decreases after five or six hours the viscosity is not so different as that at the beginning. This property of glutinous rice starch does not cause any trouble in manufacturing stars, but the paste of a composition which contains glutinous rice starch must not be left more than half a day. 

Glutinous rice starch has the smallest hygroscopic degenerative nature of all popular starches, but for long storage it is preferable to place the product which contains glutinous rice starch in dry condi-... 

Fig,56 and 57 shows the influence of glutinous rice starch upon a chlorate composition and a perchlorate composition respectively when stars are manufactured with it as a binder. The symbols are as follows ... 

For example, a 3 nim cubic cut starofthe chlorate composition containing k% glutinous rice starch is denoted by a point P in Fig,56 (the half thickness of the star is 1,5 mm). We know from the lines that the star is dried in 1,5 hours in a warm-air drier at 50°C or in 22 hours in a room at normal temperature. It takes more than 5 minutes at room temperature to completely soak it with water. The hardness of the star is 12 kg if it is dried in a room at a normal temperature and 10,5 kg... 

Fig.56 Content of glutinous rice starch and the characteristics of a chlorate composition(67 parts potassium chlorate, Ik parts BL combustion agent, 13 parts strontium carbonate and X parts starch by weight).

---