Flexibilized vinyl polybutadiene maleimide resins

A peroxide curable composition comprising the reaction product of a vinyl polybutadiene reactant that is at least about 80 percent 1,2-vinyl polybutadiene segments and a maleimide reactant comprising a mixture of a first maleimide selected from the group consisting of maleimides having the general formula:

• ##STR35## wherein a+c is from about 1 to about 5 and b is from about 13.5 to about 45.5;
• and ##STR36## wherein the sum of x, y and z is from about 1 to about 10 and each R is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical and a halogen;
• and a second maleimide selected from the group consisting of maleimides having the general formulas:
• ##STR37## where n is a number from 0.1 to about 5;
• ##STR38## where n is a number from 0.1 to about 5;
• ##STR39## where n is a number from 0.1 to about 5;
• and ##STR40## where n is a number from 0.1 to about 5;
• wherein each R is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical and a halogen and wherein the weight ratio of the first maleimide to the second maleimide in the mixture being from about 1 to 5 to about 5 to 1.

A method of producing a thermoset vinyl polybutadiene-maleimide resin comprising the steps of:

• (a) reacting a vinyl polybutadiene providing pendant vinyl groups, having a molecular weight of about 500 to about 5000 and at least about 80 percent 1,2-vinyl polybutadiene segments with a maleimide selected from the group consisting of
• (i) an aliphatic bismaleimide of the general formula:
• ##STR47## wherein a+c is from about 1 to about 5 and b is from about 13.5 to about 45.5;
• (ii) an aliphatic trismaleimide of the general formula:
• ##STR48## wherein the sum of x, y and z is about at least 1;
• (iii) a cycloaliphatic maleimide of the general formula:
• ##STR49## (iv) a cycloaliphatic maleimide of the general formula:
• ##STR50## where n is a number from 0.1 to about 5;
• (v) a cycloaliphatic maleimide of the general formula:
• ##STR51## where n is a number from 0.1 to about 5;
• (vi) an aromatic maleimide of the general formula:
• ##STR52## where n is a number from 0.1 to about 5;
• and (vii) an aromatic maleimide of the general formula:
• ##STR53## where n is a number from 0.1 to about 5;
• and wherein each R is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical and a halogen, and with at least one first peroxide-free radical initiator capable for forming maleimide grafts between vinyl polybutadiene butadiene segments to form a prepolymer;
• and
• (b) curing the maleimide grafted vinyl polybutadiene prepolymer by heating in the presence of a second peroixde-free radical initiator to cure the prepolymer through the pendant vinyl groups forming a thermoset resin.

A method of producing a hard thermoset vinyl polybutadiene-maleimide resin comprising the steps of:

• (a) reacting a vinyl polybutadiene, providing pendant vinyl groups, having a molecular weight of about 500 to about 5000 and at least about 80 percent 1,2-vinyl polybutadiene segments with a mixture of maleimides comprising a first maleimide selected from the group consisting of maleimides having the general formula:
• ##STR54## wherein a+c is from about 1 to about 5 and b is from 13.5 to about 45.5;
• and ##STR55## wherein the sum of x, y and z is about at least 1;
• and a second maleimide selected from the group consisting of maleimides having the general formulas:
• ##STR56## where n is a number from 0.1 to about 5;
• and ##STR57## where n is a number from 0.1 to about 5, and wherein each R is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical and a halogen, and with at least one first peroxide-free radical initiator capable of forming maleimide grafts between vinyl polybutadiene segments to form a prepolymer;
• and (b) curing the maleimide grafted vinyl polybutadiene prepolymer by heating in the presence of a second peroixde-free radical initiator to cure the prepolymer through the pendant vinyl groups forming a hard thermoset resin.

A peroxide curable composition comprising the reaction product of a vinyl polybutadiene reactant having pendant vinyl groups capable of high temperature peroxide cure and a maleimide reactant selected from the group consisting of:

• (i) an aliphatic bismaleimide of the general formula:
• ##STR64## wherein a+c is from about 1 to about 5 and b is from about 13.5 to about 45.5;
• (ii) an aliphatic trismaleimide of the general formula:
• ##STR65## wherein the sum of x, y and z is about at least 1;
• and where R in each of the above formulas is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical, and a halogen.

A method of producing a thermoset vinyl polybutadiene-maleimic resin comprising the steps of:

• (a) reacting a vinyl polybutadiene providing pendant vinyl groups, having a molecular weight of about 500 to about 5000 and at least about 80 percent 1,2-vinyl polybutadiene segments with a maleimide selected from the group consisting of
• (i) an aliphatic bismaleimide of the general formula:
• ##STR68## wherein a+c is from about 1 to about 5 and b is from about 13.5 to about 45.5;
• (ii) an aliphatic trismaleimide of the general formula:
• ##STR69## wherein the sum of x, y and z is about at least 1;
• and wherein each R is independently selected from the group consisting of hydrogen, an aliphatic group containing 1 to 2 carbon atoms, a benzenoid radical and a halogen, and with at least one first peroixde-free radical initiator capable of foriming maleimide grafts between vinyl polybutadiene segments to form a prepolymer;
• and
• (b) curing the maleimide grafted vinyl polybutadiene prepolymer by heating in the presence of a second peroixde-free radical initiator to cure the prepolymer through the pendant vinyl groups forming a hard thermoset resin.