Modifier for polyester fiber as well as preparation method and application of the same

A modifier for polyester fiber, comprising the following components based on parts by weight:

• 10-25 parts of ethylene glycol;
• 15-25 parts of dimethyl terephthalate;
• 1-50 parts of organosilicon having a general formula:
• where
• R1 and R2 respectively stand for an alkoxy with 1-10 carbon atoms,
• R3, R4, R5 and R6 for hydrogen, methyl, and ethyl, and
• n stands for a number of repeating units and is of a value such that the molecular weight of a polyester/polyether/organosilicon terpolymer of the modifier is in a range of 1000-5000 dalton;
• 0.2-1 parts of metal acetate with a molecular weight of 1000-20000 dalton as a catalyst;
• and
• 80-170 parts of compounds selected from one, two or more kinds of two-hydroxy-end polyethers with a general formula of (I), (II) or (III):
• H(OCH2CH2)mOH (I),
• where m stands for a number of repeating units and has a value such that the molecular weight of the two-hydroxy-end polyether with the general formula of (I) is from 10000 to 20000 dalton;
• H(OCH2CH(CH3))zOH (II),
• where z stands for a number of repeating units and has a value such that the molecular weight of the two-hydroxy-end polyether with the general formula of (II) is from 1000 to 5000 dalton;
• or
• H(OCH2CH2)p(OCH2CH(CH3))qOH (III),
• where p and q stand for a number of repeating units and have values such that the molecular weight of the two-hydroxy-end polyether with the general formula of (HI) is from 5000 to 9000 dalton.