molar ratio with dithiol pib hydrogen peroxide may be added to the solution while bubbling in air and stirring vigorously in a 2 1 ratio with dithiol pib pib disulfide precipitates from the solution the polymer may be purified by dissolving it in thf and precipitating it into a cold methanol acetone mixture the resulting polymer is expected to be a high molecular weight pib disulfide containing blocks of poly isobutlylene connected by disulfide bonds the average number of disulfide bonds in each chain is expected to be 8 the u03b1 u03c9 thiol functionalized poly isobutylene chains from example 10 or other dithiol functionalized pib chains like those in example 11 may also be used to create a network using the method established in example 6 dithiol functionalized pib may be dissolved in thf and reacted with triethylamine in a 2 25 1 molar ration of amine to pib ethyl acetate can be added in a 5 3 volume ratio with thf as described in example 6 to the mixture hydrogen peroxide may be added in a 2 1 ratio with the pib poly ethylene glycol peg chemical formula hoch 2 ch 2 och 2 ch 2 n oh is a highly versatile water soluble polymer that has been used in the biomedical field for decades peg chains with thiol functionalization at the u03b1 and u03c9 positions may be linked together via disulfide bonds created using the newly developed oxidizing system dithiol peg may be dissolved in deionized water and stirred for two hours to.