mSA-CS bipolar membrane was prepared by sodium alginate (SA) and chitosan (CS), which were modified by Ca^2＋ and glutaraldehyde (GA) as linking reagents, respectively. The viscosity of the mCS precursor solution, moisture content, and ion exchange capacity of mSA, mCS, as well as the influence of an acid-base concentration were investigated. The mSA-CS membrane was characterized by FTIR, SEM, TG and mechanism performance, and used as a separator in the electrolysis cell to produce thioglycolic acid (TGA). The experiment results showed that TGA was prepared effectively by electroreduction of dithiodiglycollic acid (DTDGA) with the mixture of TGA (w＝4.61%) and DTDGA in the cathodic room. The current efficiency was up to 66.7% at room temperature with the current density of 10 mA•cm^－2. Compared with the traditional of metal reduction method, the electroreduction technology saves the zinc powder and eliminates the pollution to environment.

Key words: bipolar membrane, sodium alginate, chitosan, thioglycolic acid, dithiodiglycollic acid