A Polyhedral oligomeric silsesquioxane (POSS) modified Ziegler-Natta catalyst is reported to synthesize the weakly entangled ultra-high molecular weight polyethylene at a high temperature and with a high activity. Incorporation of POSS can form numbers of aggregates with a mean size of 48 nm adsorbing on the surface of SiO₂. The structure of nanoaggregates is evidenced by the experiments and theoretical calculations where one POSS can coordinate with multiple MgCl₂ molecules serving as an electric donor to the further immobilized TiCl₄. The catalyst is thus featured by two distinct active regions positioned in the POSS/MgCl₂ nanoaggregates and δ-MgCl₂, respectively. The former regions present extremely low activity on ethylene polymerization, which function as horizontal separators for isolating the active TiCl₄ sites and the growing chains. This catalyst exhibits an exceptional activity (i.e. 1.3 × 10⁶ gPE mol_Ti⁻¹ h⁻¹ bar⁻¹) for the synthesis of weakly entangled polyethylene at 60 °C.

据报道，多面体低聚倍半硅氧烷（POSS）改性的齐格勒-纳塔催化剂可在高温下以高活性合成弱缠结的超高分子量聚乙烯。POSS的掺入可以形成许多聚集在SiO ₂表面上的平均尺寸为48nm的聚集体。通过实验和理论计算证明了纳米聚集体的结构，其中一个POSS可以与多个MgCl ₂分子配合，充当进一步固定化TiCl ₄的电供体。该催化剂因此通过定位在POSS /氯化镁两个不同的有源区特色₂纳米聚集体和δ -MgCl ₂， 分别。前一个区域在乙烯聚合反应中表现出极低的活性，其充当水平分隔物以隔离活性TiCl ₄位点和生长链。该催化剂在60°C下表现出优异的活性（即1.3×10 ⁶  gPE mol _Ti ^-1  h ^-1  bar ^-1）。