The production of a plastic form sulfate lignin

Abstract

Lignin was refluxed with four different metallic salts. In each case, the salt treatment was followed by treatment with hydrogen sulfide. The SnCl₂ treated lignin possessed the best molding characteristics.

To determine the value of the salt treatment and the hydrogen sulfide treatment lignin was treated with SnCl₂ only and molded, lignin was treated with hydrogen sulfide only and molded, and lignin was treated with SnCl₂ followed by hydrogen sulfide and molded. Lignin was not treated in any way was also molded. Lignin treated with SnCl₂ followed by treatment with hydrogen sulfide had the best water absorption characteristics of any run made in this investigation. Lignin not treated at all had the highest relative impact strength.

Stannous lignin was condensed with ½ mol, 1 mol, and 2 mols of formaldehyde in the presence of NaOH> All molded samples made from formaldehyde condensed lignin had very poor flow in the mold and very poor water absorption characteristics.

Stannous lignin was condensed with a mixture of formaldehyde and furfural. The amount of formaldehyde remained fixed at ½ mol whereas ½ mol, 1 mol, and 1½ mols of furfural were used. A molded sample that had been condensed with a mixture of ½ mol of formaldehyde and 1 mol of furfural had the highest relative impact strength of any sample in this investigation.

Stannous lignin was treated with ½ mol, 1 mol, and 2 mols of furfural. Better flow in the mold was obtained when furfural was used than was obtained in any of the other tests. It was found that 1 mol of furfural was the best quantity to use. A run was made using zinc sulfate treated lignin instead of stannous lignin. The zinc sulfate treated lignin when condensed with furfural had a lower per cent of water absorption than the stannous lignin when condensed with furfural. This low water absorption value was equaled only by stannous lignin which was not treated with a condensing agent.