摘要:

Major emphasis is placed on the phase behavior of miscible polymer blends. To understand the complex phase behavior of blends, a refined version of an equation-of-state theory is discussed. This theory makes the simultaneous occurrence of upper critical solution temperature and lower critical solution temperature in blends of high molar mass polymers conceivable. The kinetics of isothermal phase dissolution as it emanates from different experimental routes is discussed in terms of CahN′s linearized theory of phase separation. The rate of phase dissolution varies as a function of quench depth, which indicates the rate is directed by both the thermodynamic driving force and the mobility.

ISSN:0022-233X    

DOI:10.1080/00222339009351511

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A report is given of progress achieved during a 5-year period for describing the solidification of polymers by crystallization. Emphasis is placed on the fact that the classical quasi-equilibrium treatment of solidification under heat transfer conditions (as known under the heading of moving boundary value problems) is unable to predict any texturing in one-component systems. For polymers which are notorious for their slow approach to thermodynamic equilibrium, the local equilibrium theories, which are popular in metallurgy, are not discussed. In the present paper we show how to cope with nucleation under changing temperature conditions. Use is made of an adaptation of Avrami's theory to nonisothermal conditions, as recently proposed. Experimental work is extended to conditions of flow, where nucleation is enhanced. We show the possibility of theoretically describing this latter phenomenon.

ISSN:0022-233X    

DOI:10.1080/00222339009351512

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The initial structures of thin polyethylene films and of thin slices obtained from thicker specimens crystallized at temperature gradient in the modification process by styrene and polystyrene are studied. Comparison of the structures of these two types of samples shows clearly that the initial morphology and lamellar structure of the matrix has a basic influence on the modification process.

ISSN:0022-233X    

DOI:10.1080/00222339009351513

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/00222339009351514

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/00222339009351515

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/00222339009351516

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/00222339009351517

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor