Polystyrene/bisphenol a polycarbonate (PS/PC) molecular composite by in situ polymerization. II. Effect of different molecular size of PC on the blending behavior and properties

Through the polymerization and grafting reaction of bisphenol A dianhydride and bisphenol A diamine, the polyimide activator (PI activator) of acyl caprolactam end capping is obtained and then the anionic in-situ polymerization modified nylon 6 resin is obtained. Viscosity analysis shows that PI consumption is higher than 0.1 (of monomer mass), the reaction temperature is higher than 160°C, the viscosity rises rapidly in a short time and the rapid polymerization molding can be realized; when PI consumption is higher than 0.15 (of monomer mass), the water absorption of matrix resin will be lower than 1.4%; compared with the nylon resin, its water absorption is significantly lowered and its mechanical property is improved greatly; microscopic analysis shows that PI molecules fail to enter the crystalline phase of the nylon 6 and form lamellar crystals in the nylon matrix, which plays a role of enhancement and obstruction; differential thermal analysis shows that PI reduces the melting enthalpy and melting point temperature of nylon 6 resin, which indicates that PI reduces the crystallization capacity of nylon 6.

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Structure-Property Studies on a Series of Polycarbonate-Polydimethylsiloxane Block Copolymers

Rubber Chemistry and Technology ◽

10.5254/1.3535086 ◽

1980 ◽

Vol 53 (5) ◽

pp. 1160-1169 ◽

Cited By ~ 15

Author(s):

S. H. Tang ◽

E. A. Meinecke ◽

J. S. Riffle ◽

J. E. McGrath

Keyword(s):

Block Copolymers ◽

Bisphenol A ◽

Elevated Temperatures ◽

In Situ Polymerization ◽

Soft Segment ◽

Thermoplastic Elastomers ◽

Structure Property ◽

Polydimethyl Siloxane ◽

Bisphenol A Polycarbonate ◽

Siloxane Oligomers

Abstract Block copolymers composed of hard and soft segments form an interesting class of materials ranging from thermoplastics to thermoplastic elastomers depending on their composition and/or the size of segments. These materials have attracted much attention in the past decade because by careful tailoring, polymers of desired properties can be obtained. Yet they are thermoplastic in nature and can be processed and even reprocessed thermally. Among the common elastomers that can be used as the soft segment in a block copolymer, polydimethyl-siloxane is of special interest due to its great thermal stability at elevated temperatures and high flexibility at low temperatures. Block copolymers containing polydimethylsiloxane as the soft segment and various thermoplastics such as poly(α-methylstyrene), polystyrene, and polysulfone, etc., as the hard segment, have been synthesized and studied. A group of randomly alternating block copolymers of bisphenol-A polycarbonate and polydimethylsiloxane have also been prepared by in situ polymerization of dichloro-terminated siloxane oligomers and bisphenol-A and phosgene. The properties of these block copolymers as well as those of the others have been discussed to some extent in a general review. This work reports the results of a study on the structure-property relationship of a series of perfectly alternating block copolymers of bisphenol-A polycarbonate and polydimethylsiloxane synthesized via different routes. They were prepared by silylamine-hydroxyl reaction. Slightly less than the stoichiometric quantity of siloxane oligomers was incrementally added to a hydrated solution of the polycarbonate in refluxing chlorobenzene. The reaction can be represented by the simple scheme:

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