Bulk and solution properties of a thermo-responsive rod–coil block polymer based on poly(N-isopropylacrylamide)

RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 49028-49039 ◽  
Author(s):  
Peng Liu ◽  
Jiexing Liang ◽  
Shen Chen ◽  
Hailiang Zhang
Keyword(s):  
Molecular Weight ◽  
Diblock Copolymers ◽  
Solution Properties ◽  
Block Polymer ◽  
Molecular Weight Dependence

Molecular weight dependence on thermoresponsive behaviors of rod–coil diblock copolymers (x indicates the DP of rod PHIPPVTA blocks).

Molecular weight dependence of lamellar domain spacing of diblock copolymers in bulk

1990 ◽  
Vol 23 (19) ◽  
pp. 4313-4316 ◽  
Author(s):  
Yushu Matsushita ◽  
Katsuaki Mori ◽  
Ryuichi Saguchi ◽  
Yasushi Nakao ◽  
Ichiro Noda ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Diblock Copolymers ◽  
Molecular Weight Dependence

The Characteristic Research of Two Kinds of Block Polymer

2011 ◽  
Vol 356-360 ◽  
pp. 74-77
Author(s):  
Qing Bo Yu ◽  
Xian Hua Li ◽  
Yu Lun Tao ◽  
Guo Jun Cheng
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Methyl Acrylate ◽  
Diblock Copolymers ◽  
Triblock Copolymers ◽  
Glycidyl Ether ◽  
Monomer Conversion ◽  
Block Polymer ◽  
Allyl Glycidyl Ether ◽  
Living Free Radical Polymerization

Dual end and single end MacroRAFT agents of polystyrene were obtained respectively by polymerizations of styrene in the presence of benzyl 1H-imidazole-1- carbodithioate (BICDT) and 4,4‘-bis(imidazole-1-carbodithioatemethyl)biphenyl (ICTMP) via the thermal initiation. Then copolymerization of allyl glycidyl ether（AGE） with methyl acrylate（MA） was performed to prepare the functional block copolymers in the presence of PSt maeorRATF agents. The results show that the process has good characteristics of living free radical polymerization. However, the top monomer conversion of triblock copolymers comparing diblock copolymers is lower under the same theory molecular weight and the content of monomer.

Structure and Solution Properties of High Molecular Weight Butadiene-Styrene Copolymers

1957 ◽  
Vol 30 (1) ◽  
pp. 315-325
Author(s):  
R. B. MacFarlane ◽  
L. A. McLeod
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Complex Structure ◽  
Mixed Solvents ◽  
Solution Time ◽  
Solution Viscosity ◽  
Solution Properties ◽  
Molecular Weight Range ◽  
Viscosity Measurements ◽  
Commercial Practice

Abstract Production of high molecular weight copolymers of butadiene and styrene for use in oil-extended rubbers has aroused interest in the solution properties of copolymers above the molecular weight range commonly encountered in commercial practice. It has been observed that solubility of such polymers in toluene is a time-dependent phenomenon and the apparent solubility can increase continuously, in the absence of agitation, for as long as 800 hours. Although a standard Harris cage solubility test may show the presence of 50% gel, other properties do not confirm the presence of any appreciable quantities of insoluble material. Mild agitation rapidly promotes almost complete solubility. Dilute solution viscosity measurements are very misleading unless the influence of solution time is recognized and apparent intrinsic viscosities rise progressively with time of contact of the sample with solvent. This time-dependence of solution has been found to occur at conversions higher than 50% and is also a function of the amount of modifier used in the polymerization recipe. It has not been possible to shorten the solution time for viscosity measurements by mild heating or gentle agitation. Mixed solvents cause a change in the amount of increase of the apparent intrinsic viscosity but do not shorten the time to equilibrium. Measurement of the slope constant in the Huggins viscosity equation indicate that these solubility and viscosity effects coincide with the appearance of a marked degree of branching in the polymer molecules. The effect is, therefore, interpreted as being caused by the relatively slow disentanglement of molecules of complex structure.

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