Moldable synthetic resin compositions

Polymerizable, mouldable compositions comprise (1) 2-80 parts by weight of a butadiene polymer containing polymerizable ethylenically unsaturated groups and (2) 100 parts by weight of a liquid organic monomer containing polymerizable ethylenically unsaturated groups, at least 75% by weight of component (2) being the acrylic acid ester of tricyclo - [5,2,1,02,6]-decene - (3) - ol - (9). Component (1) may be butadiene homopolymer, particularly the 1,4-polymer; or a copolymer of butadiene with, for example, styrene, a -methyl-styrene, N-vinyl-pyridine and/or acrylonitrile, particularly a copolymer in which the butadiene units are 1,2-linked. Additional monomers which may be included in component (2) can be, for example, those mentioned above in the butadiene copolymers. The compositions may include a polymerization inhibitor, e.g. t-butylhydroquinone or t-butylpyrocatechol; a filler or reinforcing agent, e.g. a glass fibre mat; a pigment; a flame retardant, e.g. a chloroparaffin and tri-(b -chloroethyl) phosphate (stabilized with an epoxidized monoester of glycerol and versatic acid). The compositions are moulded and polymerized in the presence of an initiator such as cyclohexanone peroxide or benzoyl peroxide in combination with a metal salt, e.g. cobalt naphthenate or amine, e.g. dimethylaniline, accelerator.ALSO:The acrylic acid ester of tricyclo-[5,2,1,02,6]-decene -(3)-ol-(9) is prepared by reacting excess acrylic acid with dicyclopentadiene in the presence of BF3 and hydroquinone, firstly at 40 DEG C. and subsequently at 65 DEG C. After removal of the excess acid, washing and extracting, the ester product is distilled in vacuo in the presence of phenothiazine.