【摘要】 用溶液高分辨￣（１３）ＣＮＭＲ谱首次研究了由二苯甲酮（ＢＰ）光引发低密度聚乙烯模型化合物直链烷烃ｎ－Ｃ＿（２４）Ｈ＿（５０）交联所产生的Ｈ型交联点的结构特征．现已检测和鉴定了光交联样品中与Ｈ型交联点相联系的－ＣＨ，α－ＣＨ＿２和β－ＣＨ＿２上碳的共振谱线，其数据与Ｈ型交联点模型化合物、γ－辐射交联正烷烃和聚乙烯所得到的结果符合得很好．在４０．８３ｐｐｍ处出现的一个新峰可指认为Ｈ型文联点的次甲碳，其相应的３１．５７和２８．３７ｐｐｍ处的另外两个新峰分别指认为相邻的α－ＣＨ＿２和β－ＣＨ＿２上碳的共振．本工作中的定量研究表明：在真空和熔融态条件下莱外光照３－５ｍｉｎ的样品中Ｈ型交联点的数目据估计为每１００００个碳原子８．５～１１．０个．更多还原

【Abstract】 H－type cross－links produced by photoinitiated cross一linking of n－C₂₄H₅₀ as amodel compound of polyethylene in the presence of benzophenone asphotoinitiator have been studied for the first time by solution－state ¹³C NMRspectroscopy．Resonance lines assigned to the CH，α－CH₂，andβ－CH₂ carbons as-sociated w1th H－type cross－links have been observed and identified for thephotocross－linked samples，and compared with data from the model compound andγ－irradiation cross－linking of n－paraffins and polyethylene．A new resonance lineat 40．83 ppm is attributed to methine carbons in H－links．The other two new reso-nances at 31．57 ppm and 28．37 ppm are assigned to α－CH₂ and β－CH₂，respectively．The quantitative studies in this work show that the number of H－links is estimated tobe 8．5－11．0 per 10000 carbon atoms for samples UV－irradiated in vacuum in the melt for 3－5min．更多还原