ABSTRACT

Polypropylene random copolymer (PPR) and polybutene-1(PB-1) are blended and long-chain branched (LCB) in the reactive extruder. The optimum amount of PB-1 resin, peroxide (DCP) and trimethylolpropane triacrylate (TMPTMA) for long-chain branching of PPR and probe topology formed by the branches were investigated. Fourier transformed infrared spectroscopy (FTIR) used to measure the branching degree and efficiency as well as obtaining TMPTMA grafts on PPR. Oscillatory shear rheological properties including complex viscosity, storage modulus, loss tangent, and uniaxial elongational rheometry were studied to differentiate the LCB-PPR from unmodified PPR with almost similar molecular weight samples. The LCB structure modified samples with TMPTMA and DCP, prominent higher zero-shear viscosity, longer relaxation time and pronounced strain-hardening behavior. It was found that different amount of DCP and TMPTMA can affect strain-hardening behavior and topology of branches and subsequently the foaming ability. PB-1 resin found to have a positive effect because of more sensibility to β-scission degradation and mobilizing effects. The optimization of PB-1 for the highest zero-shear viscosity, shear, and uniaxial rheological behavior is achieved at 10 wt% PB-1, while 0.08% of DCP and 3% of TMPTMA are optimum amounts of additives needed for long-chain branching process. The optimum blend could be a great alternative for foaming applications.

摘要

将聚丙烯无规共聚物（PPR）和聚丁烯-1（PB-1）混合，然后在反应挤出机中形成长支链（LCB）。研究了PPR长链支化的最佳PB-1树脂，过氧化物（DCP）和三羟甲基丙烷三丙烯酸酯（TMPTMA）的量以及由支链形成的探针拓扑。傅立叶变换红外光谱（FTIR）用于测量分支度和效率，以及在PPR上获得TMPTMA接枝。研究了包括剪切粘度，储能模量，损耗角正切和单轴伸长流变学在内的振荡剪切流变特性，以区分分子量几乎相似的LCB-PPR和未改性的PPR。用TMPTMA和DCP改性的LCB结构样品，具有显着更高的零剪切粘度，更长的松弛时间和明显的应变硬化行为。发现不同量的DCP和TMPTMA会影响应变硬化行为和分支的拓扑结构，进而影响发泡能力。发现PB-1树脂具有积极作用，因为它对β断裂的降解和动员作用更敏感。在PB-1为10 wt％的情况下，可以实现PB-1的最佳零剪切粘度，剪切和单轴流变性能的最高优化，而长链所需的最佳添加剂量为0.08％的DCP和3％的TMPTMA。分支过程。最佳的共混物可能是发泡应用的理想选择。发现PB-1树脂具有积极作用，因为它对β断裂的降解和动员作用更敏感。在PB-1为10 wt％的情况下，可以实现PB-1的最佳零剪切粘度，剪切和单轴流变性能的最高优化，而长链所需的最佳添加剂量为0.08％的DCP和3％的TMPTMA。分支过程。最佳的共混物可能是发泡应用的理想选择。发现PB-1树脂具有积极作用，因为它对β断裂的降解和动员作用更敏感。在PB-1为10 wt％的情况下，可以实现PB-1的最佳零剪切粘度，剪切和单轴流变性能的最高优化，而长链所需的最佳添加剂量为0.08％的DCP和3％的TMPTMA。分支过程。最佳的共混物可能是发泡应用的理想选择。