Raw material for preparing liquid branched-chain AKD as well as preparation method and application of liquid branched-chain AKD

The invention relates to a sizing agent for papermaking and particularly relates to a raw material for preparing liquid branched-chain AKD as well as a preparation method and application of the liquid branched-chain AKD. The raw material for preparing liquid branched-chain AKD is an alkyl fatty acid mixture of which the melting point is -15 to 35 DEG C and the degree of saturation is greater than 97%. The preparation method of the liquid branched-chain AKD comprises the following reaction steps of acylating chlorination and dimerization. The prepared liquid branched-chain AKD is used as the sizing agent for papermaking. By the liquid branched-chain AKD, the performance of the paper can be improved; the energy consumption during papermaking is decreased; the wastewater emission is decreased; the papermaking cost is reduced and the long-term running performance of the papermaking machine is improved.