Synthesis,Structure,and Performance Of Piperazine/Polyether Modified Silicone Softeners

These days amino/polyether modified silicone copolymers are widely used as fabric softeners. Compared with traditional amino silicones, they have better emulsification properties and can give fabrics more comprehensive performance, especially hydrophilicity. Therefore, in this paper, the amino/polyether modified silicone copolymers were studied. And the aim was to impart cotton fabrics with improved softness and meanwhile maintain good whiteness and hydrophilicity. Specifically, two kinds of piperazine/polyether co-modified polysiloxanes used as silicone fabric softeners were studied, including silicone synthesis, emulsification, and application in cotton fabrics. In the synthesis step, bulk polymerization, hydrosilylation, and ring-opening reaction were adopted without the use of toxic solvents like toluene. The structures of the silicones were analyzed by GPC,1HNMR, FTIR, and TGA. After cotton fabrics were treated with silicone emulsions, their properties including whiteness, softness, wettability, hydrophilicity, and film morphology were characterized. Also, several other traditional amino polysiloxanes were synthesized and compared. Although amino silicones were once widely used, for they impart fabrics with super softness. However, their disadvantages are quite obvious, including hydrophobicity, easily yellowing, etc. Thus, various kinds of modified amino polysiloxanes gradually appear and amino/polyether co-modified polysiloxane is one of them.In the second chapter, piparazine/(polyethylene glycol) modified polysiloxane (PTSO-PEG) was discussed. The following results were found:PTSO-PEG treated cotton fabrics can maintain better whiteness and hydrophilicity than aminopropyl end-capped polysiloxane treated fabrics (ATSO/cotton). In terms of fabric softness, ATSO/cotton was slightly better than PTSO-PEG/cotton. But when the length ratio of polysiloxane to PEG chains increased, the softness of PTSO-PEG/cotton can reach the same level as that of ATSO/cotton. However, the disadvantage for PTSO-PEG was that the synthesis of piperazine end-cap was complicated and thus this route was not beneficial for commercial use. Considering this, another route was designed using all materials that are commonly used in market and the results are shown in the third chapter.In the third chapter, piparazine/polyether modified polysiloxane (PHMS-APE-P) was discussed and three amino silicones were compared, including piperazine modified polysiloxane (PHMS-AGE-P), N-β-aminoethyl-y-aminopropyl polysiloxane (AASO), and aminopropyl end-capped polysiloxane (ATSO). The following results were found:PHMS-APE-P, PHMS-AGE-P, and ATSO can be easily emulsified into transparent micro-emulsions, with particle size less than 100 nm. But AASO was emulsified into milky white emulsions with particle sizes of 335 nm. This may be related with the uneven distribution of amino groups in its polysiloxane chains. In terms of fabric properties, PHMS-APE-P/cotton showed best hydrophilicity and wettability, with water wetting time of 2.0 s and water contact angle of 96.8°. PHMS-AGE-P and AASO treated cottons showed hydrophobic surface. The results indicated that both polyether chains and cyclic piperazine groups can reduce the hydrophobic effects of polysiloxane chains to the cotton fabrics. The softness of fabrics was affected by polysiloxane chain length and the whiteness was affected by amino group values.