The Effect Of Block Copolymer Distribution On The Blends Rheological Properties

Polymer blending technology is an important field of polymer science research.Polymer blends provide an important choice for people to address their application needs.Polymer blending has great advantages over the development of new polymer structures.The existing polymers are mixed to obtain new substances of industrial value,which saves research and development expenses compared with the development of new monomers and polymers.In addition,the cost of large-scale production and commercialization is reduced.Additionally,the blends can provide a combination of properties that are not readily available from new polymer structures.Polymer blending technology has been applied in all areas of our daily lives.There are many different types of polymer blends,the most fundamental differences of which are determined primarily by their phase."Morphology without rheology is zoology".This paper explores the effects of block copolymer phase boundary distribution on the properties of blended streams by adjusting multiple variables.The second chapter of this paper introduces the synthesis of raw materials and the preparation and testing of samples.Homopolymers and block copolymers of different molecular weights were synthesized by reversible addition-fragmentation chain transfer polymerization.One end of the homopolymer molecular chain and the PMMA end of the block copolymer.It is a highly polar cyano group.The cyano group is the residual end group of the initiator azobisisobutyronitrile.The blending compatibilization system was prepared by using single telechelic polymer as raw material.In the transmission electron micrograph of the sample,almost no block copolymer was observed to form micelles in the homopolymer,which greatly improved the compatibilization efficiency of the block copolymer..For single component polymers,the introduction of polar end groups greatly enhances the mechanical properties of the polymer,especially toughness.The third chapter of this paper mainly compares the morphology and rheological behavior of different block ratio block copolymer compatibilization systems in two blending sequences.The block ratio and the blending order together determine the rate of diffusion of the block copolymer in the blend.For the system,((continuous phase + block copolymer)+ dispersed phase)blending sequence,the block copolymer is stable at the phase interface content,and the compatibilizing effect is good.We can reverse the distribution of the block copolymer in the blend from the size of the storage modulus in the high and low frequency regions of the rheological curve.The fourth chapter of this paper mainly discusses the compatibilizing effect of two different molecular weight and highly asymmetric block copolymerization on different molecular weight dispersed phases.Different blends showed a rich phenomenon in the three frequency regions of high,medium and low rheological curves.The molecular weight of the dispersed phase homopolymer increases,and the storage modulus in the high frequency region increases.At the same time,the molecular weight of the block copolymer and the molecular weight of the dispersed phase are increased.Since the total dry and wet brushing degree is constant,the storage modulus of the blend coincides in the intermediate frequency region.It is affirmed that the dry and wet brush theory judges the emulsification effect in the intermediate frequency region where the droplets of the dispersed phase are recovered.However,the interfacial shear modulus reflected in the low frequency region depends on the degree of entanglement of the inner and outer layers of the block copolymer at the interface.