Kinetics of miniemulsion polymerization as revealed by calorimetry

被引:84
作者
Bechthold, N [1 ]
Landfester, K [1 ]
机构
[1] Max Planck Inst Colloids & Interfaces, D-14424 Golm, Germany
关键词
D O I
10.1021/ma000061h
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
The kinetic behavior of styrene miniemulsions with a hydrophilic initiator was investigated by calorimetry, focusing on the studies of parameters such as (a) the amount of surfactant and (b) the quantity of the initiator. Their influence on the net reaction time of polymerization and on the nucleation mechanism in comparison to other heterophase polymerization types is discussed. The course of miniemulsion polymerization kinetics is characterized by three distinguishable intervals. The first two intervals can be defined by the average number of radicals per particle, (n) over bar: during the first interval, (n) over bar increases until a plateau value of 0.5 is reached at the onset of the second interval. The beginning of the last interval is defined by a sharp increase of (n) over bar. Because of the nature of the first interval, all miniemulsion droplets are nucleated within this interval at a specific time, and therefore the individual conversion in each droplet has reached a different level. Every miniemulsion droplet can be perceived as a separate nanoreactor which does not interact with the others. Independent of the amount of initiator as well as the particle size, i.e., the number of active sites in the system, the limit value of (n) over bar during the second interval remains 0.5. Therefore, the net polymerization time strongly decreases with decreasing particle size.
引用
收藏
页码:4682 / 4689
页数:8
相关论文
共 17 条
[1]  
Brandrup J, 1989, POLYM HDB
[2]   POLYMERIZATION OF STYRENE MINIEMULSIONS [J].
CHOI, YT ;
ELAASSER, MS ;
SUDOL, ED ;
VANDERHOFF, JW .
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 1985, 23 (12) :2973-2987
[3]  
ELASSER MS, 1997, POLYM DISPERSIONS PR, P109
[4]   A GENERAL THEORY OF THE MECHANISM OF EMULSION POLYMERIZATION [J].
HARKINS, WD .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1947, 69 (06) :1428-&
[5]  
Landfester K, 1999, MACROMOL RAPID COMM, V20, P81, DOI 10.1002/(SICI)1521-3927(19990201)20:2<81::AID-MARC81>3.0.CO
[6]  
2-G
[7]   Formulation and stability mechanisms of polymerizable miniemulsions [J].
Landfester, K ;
Bechthold, N ;
Tiarks, F ;
Antonietti, M .
MACROMOLECULES, 1999, 32 (16) :5222-5228
[8]   Miniemulsion polymerization with cationic and nonionic surfactants: A very efficient use of surfactants for heterophase polymerization [J].
Landfester, K ;
Bechthold, N ;
Tiarks, F ;
Antonietti, M .
MACROMOLECULES, 1999, 32 (08) :2679-2683
[9]   MINIEMULSION POLYMERIZATION OF STYRENE - EVOLUTION OF THE PARTICLE-SIZE DISTRIBUTION [J].
MILLER, CM ;
SUDOL, ED ;
SILEBI, CA ;
ELAASSER, MS .
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 1995, 33 (08) :1391-1408
[10]   POLYMERIZATION OF MINIEMULSIONS PREPARED FROM POLYSTYRENE IN STYRENE SOLUTIONS .1. BENCHMARKS AND LIMITS [J].
MILLER, CM ;
SUDOL, ED ;
SILEBI, CA ;
ELAASSER, MS .
MACROMOLECULES, 1995, 28 (08) :2754-2764