Preparation And Application Performance Of Self-emulsified AKD Emulsion

Nowadays,AKD alkaline sizing agent is widely used by papermaking enterprises in China.It has the advantages of low costs,high efficiency,high paper strength and durability,but AKD alkaline sizing agent still has the disadvantages of the emulsion's prone to hydrolysis,poor stability and high transportation costs,these issues have drawn the attention of researchers.In this paper,several new AKD emulsions were prepared by used different methods to increase their stability,increase solids content and reduce transportation costs.First,a new type of solid emulsifier(double hexadecyldimethylammonium chloride)was used to prepared AKD emulsion.The emulsification temperature,emulsification time,emulsion solid content,and emulsifier dosage were used to study the effects of the new emulsifiers on the water resistance,stability,particle size,and surface tension of AKD emulsions.The experimental results showed that under the condition of emulsifier dosage was 3%,emulsification time was 9 min,emulsification temperature was 75? and solid content was 10%,the Cobb value of the paper reached 29.63 g/m2.The prepared AKD emulsion had good sizing effect and the particle size of the emulsion was smaller.The emulsion had a stable storage.Second,the preparation process of AKD sizing liquid was improved and optimized.We proposed a new preparation method of AKD sizing liquid which was onepot cooking.The factors of preparation of AKD sizing liquid which were reaction temperature,reaction time,stirring speed,emulsifier dosage and solid content were studied.The optimum process conditions for the preparation of AKD size were studied.The viscosity of the size,the degree of sizing and the strength index of the ring pressure were also measured.The experimental results shown that when the temperature was 75?,reaction time was 20 min,stirring speed was 700 r/min,emulsifier dosage was 9% and sizing liquid solids content was 15%,the Cobb value of the paper reached 31.81 g/m2.The sizing liquid has better water resistance.Again,the preparation conditions of AKD multiple emulsions were studied,and the influence of different factors was explored on the stability of liquid AKD multiple emulsion systems.The experimental results shown that the first phase oil-water mass ratio was 45%,the second phase mass ratio was 60%,the proportion of lipophilic hydrophilic emulsifier was 12:1,the emulsifier dosage was 5%,the reaction temperature was 75 ?,the first phase The reaction time was 30 min,the second phase reaction time was 50 min,and the emulsifier ratio of Span:Tween was 6:4,.The stability of the system was relatively good and the relative volume fraction reached 86.1%.Finally,the "self-emulsifying" AKD neutral sizing agent was prepared by used the Instant Soaping Method.The single-factor method was used to study the different reaction temperatures,reaction times,solid content,emulsifier dosage,and shear rates on the effect of the water resistance,stability,paper contact angle,and paper surface change of the AKD emulsion after sizing.The experimental results shown that when the reaction temperature was 75?,the reaction time was 9 min,the solid content was 10%,the emulsifier dosage was 5% and the stirring speed was 10000 r/min,the emulsion sizing effect was the best.In this case,the Cobb value reached 17.03 g/m2.At this time,the viscosity of the sizing liquid was about 10 m Pa·s,the emulsion was stable,and the water resistance after the paper sizing was good.