申请人:Pennwalt Corporation
公开号:US04101464A1
公开(公告)日:1978-07-18
Cellular polymeric solids are made by mixing an acidulous or acidic polymerizable medium that is polymerizable and/or cross-linkable by a free radical mechanism (e.g. an unsaturated polyester) with an effective amount of two or more acid sensitive mono- or poly-azo compounds containing the group: ##STR1## wherein Y is an acid sensitive group (e.g. Cl, OH, --OCN, --NCO) which in the presence of an acidulous or acidic polymerizable medium causes sufficient decompsition of the azo compound that gas is released in the medium and during the decomposition the mono- or poly- azo compound promotes polymerization and/or cross-linking of the medium to provide a matrix that is sufficiently polymerized and/or cross-linked that the generated gases cause the matrix to expand, each of the remaining valences being satisfied by an organic radical; provided that any carbon atom that is directly linked to an azo nitrogen, except that of a carbonyl group, has at least two of its remaining three valences satisfied by a carbon to carbon bond or a carbon to hydrogen bond. Preferably, the mixture contains at least two such azo compounds having appreciably different sensitivity to decomposition by acid. The process is especially useful in making foamed flotation structures (e.g. boat hulls).
细胞聚合物固体是通过将可聚合和/或可交联的酸性或酸性聚合物化中介物(例如不饱和聚酯)与有效量的两种或更多的含有以下基团的酸敏感单体或多聚偶氮化合物混合而成:##STR1## 其中Y是酸敏感基团(例如Cl,OH,--OCN,--NCO),在存在酸性或酸性聚合物化中介物的情况下,引起偶氮化合物的分解,释放气体,并在分解过程中,单体或多聚偶氮化合物促进中介物的聚合和/或交联,形成足够聚合和/或交联的基质,使生成的气体导致基质膨胀,其余的价键由有机基团满足;前提是除了羰基团的偶氮氮原子直接连接的任何碳原子都有至少两个其余三个价键由碳-碳键或碳-氢键满足。最好的是,混合物中至少含有两种这样的偶氮化合物,其酸分解敏感性明显不同。该过程在制造泡沫浮力结构(例如船体)方面特别有用。