(Imino-1

4-cyclohexylenemethylene-1

4-cyclohexyleneiminododecanedicarboxyl)-co-(iminohexylimioheanedicarboxyl) copolymers (PACM12-PA66) were prepared by using 4

4'-diaminodicyclohexyl methane

dodecanedioicacid and hexanedicarboxylhexanediamino salt as the comonomers.A series of PACM12-PA66 copolymers with various PACM12 contents were prepared

and their optical and mechanical properties were studied.The results show that

when the PACM12 content was higher than 40%

the copolymer materials were transparent within the wavelength of visible light (400~800 nm).The high transparency of the transparent materials didn't decrease after heat treatment.The refractive index of the copolymers was not relative to the PACM12 content

verifying that the copolymer with PACM12 content higher than 40% had similar crystal structure

so that there was not obvious difference of refractive index among the materials.The WXRD results showed that the crystal size of copolymer materials became larger

and the crystal became more perfect as the PACM12 content decreased

while the degree of crystallinity first decreased and then increased.All of the results tested by DSC and WXRD described that the transparent copolymers with PACM12 content at 40%

75% and 100% owned a special crystal behavior

the quenched materials were almost amorphous then turned to microcrystal structure after being heat treated; while the copolymer with 34% PACM12 was easily crystallized

as a result the material lost its transparency and became opaque.Both tensile strength and impact strength of the copolymer materials are gradually improved with increasing PACM12 content.For copolymer materials with 40% PACM12 content

the tensile strength (64.28 MPa) increases by 40% and the impact strength (14 kJ/m2)increases by 33% than those of PACM12.