S. Basu, S. Malik, G. Joshi et al.
Carbohydrate Polymer Technologies and Applications 2 (2021) 100050
Fig. 1. Preparation routes for different cellulosic products used in paper making .
starch (starch:CMC = 10:1). However, separate addition (starch followed by CMC) was found to be most effective in enhancing the Mullen index by ∼ 35%, tensile index by ∼ 23% and filler retention by ∼ 50%. The work establishes the properties of CMC as strength additive and retention aid by utilizing different commercial starch and CMC varieties as well as dif- ferent pulp types e.g. virgin chemical pulp, mixed pulp, recycled pulp etc. with consistent results.
kali cellulose formation (by treating with sodium hydroxide under controlled physico-chemical conditions) followed by a reaction with gaseous ethylene oxide. This reaction results in a series of etherifica- tion of the hydroxyl groups by converting the same into hydroxyethyl groups. This makes the overall molecule water soluble. Hydroxyethyla- tion can also be done in a single step by a treatment of cellulose with high ethylene oxide concentration (200% w/w of cellulose) in pres- ence of higher alkali charge ( > 20%) at a considerably high temperature (100 °C) and often under high pressure. Hydroxyethyl cellulose has su- perlative capabilities as thickening, binding, emulsifying, and dispersing agent. It has superior water retention capabilities hence producing solu- tions of varying viscosities. For these properties, it has been utilized in paper industry as a surface sizing and pigment coating agent. Hydrox- yethyl cellulose (at a concentration 0.5–2%) has also been found to have
2.3. Hydroxyethyl cellulose
Hydroxyethyl cellulose is another attractive cellulose deriva- tive which is water soluble and non-ionic. It is prepared from bleached/delignified cellulosic substrate by a two step process ( Fig. 1 ). Industrial production of hydroxyethyl cellulose comprises of active al-
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