Interplay between the composition of LLDPE/PS blends and their compatibilization with polyethylene-graft-polystyrene in the foaming behaviour
Interplay between the composition of LLDPE/PS blends and their compatibilization with polyethylene-graft-polystyrene in the foaming behaviour
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DOI：
10.1039/c4ra16084c
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发表时间：
2015-03
期刊：
影响因子：
3.9
通讯作者：
G. P. Zhang;Wang Yuanliang;Haiping Xing;J. Qiu;J. Gong;Kun Yao;Haiying Tan;Zhiwei Jiang;T. Tang
中科院分区：
文献类型：
--
作者：
G. P. Zhang;Wang Yuanliang;Haiping Xing;J. Qiu;J. Gong;Kun Yao;Haiying Tan;Zhiwei Jiang;T. Tang
采用ROMP和ATRP相结合的方法制备了聚乙烯-g-聚苯乙烯（PE-g-PS）共聚物，用于LLDPE/PS共混体系的增容。一方面，研究了PE-g-PS对LLDPE/PS共混物形貌的影响。另一方面，以超临界CO2为物理发泡剂，采用间歇式发泡工艺，研究了不同组成的LLDPE/PS泡沫共混物的支长和PE-g-PS添加量对泡沫池形态的影响。研究发现，PE-g-PS在LLDPE/PS共混物中的存在对泡沫性能有不同的影响，这在很大程度上取决于共混物的组成（即LLDPE和PS的重量比）。研究了LLDPE/PS共混物的增容和组分的相互作用对其发泡性能的影响。合理的解释是由于共混物的相结构不同导致了界面区域的连续状态。与原始LLDPE和PS相比，海岛相结构的共混物的泡沫形态有所改善，但PE-g-PS的存在对共混物的发泡行为影响不大。相比之下，PE-g-PS的存在显著提高了共连续相结构LLDPE/PS共混物的发泡能力。这是由于两组分之间的界面粘结力增强，阻断了CO2释放的通道，在相同的发泡条件下，共混物的粘弹性不是决定发泡行为的关键因素。
Polyethylene-g-polystyrene (PE-g-PS) copolymers, which were prepared by the combination of the ROMP and ATRP method, were utilized to compatibilize LLDPE/PS blends. On one hand, the effect of PE-g-PS on the morphologies of LLDPE/PS blends was investigated. On the other hand, the influences of branch length and added amount of PE-g-PS on the cell morphology of foamed LLDPE/PS blends with different compositions were studied using supercritical CO2 as a physical foaming agent in a batch foaming process. It was found that the presence of PE-g-PS in the LLDPE/PS blends showed different influences on the foaming behaviour, strongly depending on the composition of the blends (i.e. the weight ratio of LLDPE and PS). How the interplay of compatibilization and composition of the LLDPE/PS blends affected the foaming behaviour of the LLDPE/PS blends was studied. A reasonable explanation was ascribed to consecutive states of the interfacial region, resulting from different phase structures of the blends. Compared to pristine LLDPE and PS, the blends with a sea-island phase structure showed the improved foam morphology, but the presence of PE-g-PS did not strongly influence the foaming behaviours of these blends. In contrast, the presence of PE-g-PS dramatically promoted the foaming ability of LLDPE/PS blends with a co-continuous phase structure. It was ascribed to the strengthened interfacial adhesion blocking the channel between two components through which CO2 was released, and the viscoelasticity of the blends was not the key factor to determine the foaming behaviour under the same foaming conditions in this work.