PVC Plasticized with tetracarboxylates

Polyvinyl chloride plastic compositions containing in amounts sufficient to impart plasticizing properties esters of the formula ##STR2## wherein A and C are monovalent succinic acid groups having attachment to B at either of the two carbon atoms of A or C having unsatisfied valences and a hydrogen atom attached to the other unsatisfied carbon atom;

• and wherein B is a connecting alkane or cycloalkane group of 8 to 30 carbon atoms having 2 of the above-described monovalent groups A and C, which may be the same or different, attached at carbon atoms 1 and 2 or at carbon atoms 1 and 3;
• and optionally having carbon atom 1 and carbon atom 4 connected by a 1-8 carbon methylene bridge;
• the remainder of the unsatisfied carbon valences of said bivalent hydrocarbon group being attached to hydrogen atoms;
• and wherein R.sup.1 is H and R.sup.2 and R.sup.3 are H or the same or different alkyl groups;
• X and Y are the same or different groups having the structure:
• --OR, in which R is an alkyl group having from 1 to 8 carbon atoms.