Biodegradable polyestreramide and a process of preparing

A biodegradable polyesteramide P2 having a molecular weight (Mn) of from 4000 to 40,000 g/mol, a viscosity number of from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of 0.5% by weight of polyesteramide P2 at 25° C.) and a melting point of from 50 to 255° C. P2 being obtained by reacting a mixture consisting essentially of

• b1)) a mixture consisting essentially of
• 35-95 mol % of adipic acid or ester-forming derivatives thereof or mixtures thereof,
• 5-65 mol % of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, and
• 0-5 mol % of a compound containing sulfonate groups, where the total of the individual mole percentages is 100 mol %, and
• b2) mixture a2) consisting essentially of
• a21) 99.5-0.5 mol % of a dihydroxy compound selected from the group consisting of C2-C6-alkanediols and C5-C10-cycloalkanediols,
• a22) 0.5-99.5 mol % of an amino-C2-C12-alkanol or an amino-C5-C10-cycloalkanol, and
• a23) 0-50 mol % of a diamino-C1-C8-alkane,
• a24) 0-50 mol % of a 2,2′-bisoxazoline of the formula
• where R1 is a single bond, a (CH2)q alkylene group with q=2, 3 or 4, or a phenylene group,
• where the total of the individual mole percentages is 100 mol %,
• where the molar ratio of b1) to b2) is from 0.4:1 to 1.5:1, with
• b3) from 0.01 to 40% by weight, based on component b1), of an amino carboxylic acid selected from the group consisting of the natural amino acids, polyamides with a molecular weight not exceeding 18,000 g/mol, obtained by polycondensation of a dicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10 carbon atoms, compounds of the formulae IIa and IIb
• where p is an integer from 1 to 1500 and r is an integer from 1 to 4, and G is a radical selected from the group consisting of phenylene, —(CH2)n—, where n is an integer from 1 to 12, —C(R2)H— and —C(R2)HCH2 where R2 is methyl or ethyl, and polyoxazolines with the repeating unit III
• where R3 is hydrogen, C1-C5-alkyl, C5-C8-cycloalkyl, phenyl which is unsubstituted or substituted up to three times by Cl-C4-alkyl groups, or tetrahydrofuryl, and
• b4) from 0 to 5 mol %, based on component b1), of at least one compound D having three to six hydroxyl groups or carboxyl groups or mixtures thereof, or anhydrides or dianhydrides of the carboxyl groups.