There are provided composites having near-zero uniaxial thermal expansion coefficients. One or more polyacetylenes having a negative uniaxial thermal expansion coefficient are uniaxially or biaxially oriented within one or more solid matrix materials having a positive thermal expansion coefficient to yield a composite material having a uniaxial thermal expansion coefficient which is nearly zero. The polyacetylenes are obtained by the solid-state polymerization of crystals of monomers containing at least one --C.tbd.C--C.tbd.C-- grouping per molecule. Also provided are processes for producing the above-described composites.
提供了具有接近于零的单轴热膨胀系数的复合材料。其中一个或多个具有负单轴热膨胀系数的聚
乙炔在具有正热膨胀系数的一个或多个固体基质材料内单轴或双轴定向,以产生一个单轴热膨胀系数几乎为零的复合材料。聚
乙炔是通过含有至少一个-C.tbd.C-C.tbd.C-基团的单体晶体的固态聚合获得的。还提供了制造上述复合材料的方法。