DRY MIXTURES

[:ru]Бьязотти Б.[:en]Biasotti, B.[:] [:ru]с. н. с. Центр по исследованию производных гидроколлоидов, Ламберти С. п. А., Милан, Италия[:en]Senior Scientist R&D Hydrocolloids Derivatives, Lamberti SpA, Milan, Italy[:]

[:ru]Джудичи М.[:en]Giudici, M.[:] [:ru]директор Лаборатории конструктивных элементов и красок, Ламберти С. п. А., Милан, Италия[:en]Lab Constructions & Paints manager, Lamberti SpA, Milan, Italy[:]

[:ru]Ланджелла В.[:en]Langella, V.[:] [:ru]управляющий технологическим процессом производных гидроколлоидов, Ламберти С. п. А., Милан, Италия[:en]Hydrocolloids Derivatives Technology Manager, Lamberti SpA, Milan, Italy[:]

Alitinform №1 (42) 2016 г. 92-100 p.

Abstract

Chemical admixtures are commonly used in small amounts as ingredients of building formulations, generally added to dry mix immediately before or during mixing in order to improve their properties in fresh and  / or hardened state. Among the different chemical admixture categories, several natural polysaccharides derivatives, such as cellulose and starch ethers, are often used. Recently Hydroxypropyl Guars (HPGs) have been introduced in Construction Chemistry thanks to their particular rheological behavior and additional water retention properties close to those of Cellulose Ethers (CE) representative of the market.
The aim of this work was to study HPGs performances in a fresh state formulation. It was investigated how HPGs with different degrees of substitution affect water retention, one of the main properties imparted to mortar. More specifically the experimental approach was focused on the analysis of HPGs interactions with binder and mineral fillers by detection of polymer distribution into mortar. It has been demonstrated that the right selection of the degree of substitution of the HPG allows us to obtain products useful for these applications and able to satisfy the market requirements.

Key words:

dry mix admixture; hydroxypropylguar; molar substitution (MS); water retention; polymer distribution; polymer interactions