Kinetics of spherulite and crystallite growth in isotactic polystyrene

Abstract

The rates of spherulite and crystal growth in isotactic polystyrene have been studied as a function of temperature by microscopic, x‐ray, and density methods. The effects of molecular weight and degree of isotacticity upon the spherulite growth are shown. Degree of isotacticity is the predominant factor in growth rate. Maximum rate of spherulite growth was observed at 175°C., while the maximum rate of crystal growth was observed at 190°C. Some evidence exists that polystyrenes made with the use of heterogeneous catalysts of the Ziegler type consist of heterogeneous blocks of isotactic and atactic polymers rather than polyblends.

Comparative study on quiescent crystallization kinetics of isotactic polyolefins

“…2). These include polypentene‐1 (PPT1) ( n = 2),32–34 polyhexene‐1 (PH1) ( n = 3),35 poly(3‐methyl butene‐1) (P3MB1) ( m = 0),34, 36 and polystyrene (PS) 37, 38. If we first limit ourselves to polyolefins with linear alkyl side groups shown in Figure 2(a), it is clear from our observations and those of Quinn and Powers,32 Turner‐Jones,35 and Dunham et al,34 that crystallization rates order as Crystallization rate of course depends on temperature but it seems clear that the ordering of eq.…”

“…There have also been studies of the crystallization of isotactic polystyrene,37, 38 of which chemical structure is shown in Figure 2(c). These studies indicate that isotactic polystyrene crystallizes very slowly compared to those of the isotactic polymers described above.…”

Porous structure of hypercrosslinked polystyrene: State-of-the-art mini-review

“…Data obtained in this manner for hypercrosslinked polystyrenes are given in Table 2. The apparent density presented there was measured in a mercury densimeter, while the true density was arbitrarily set to equal the density of isotactic polystyrene crystal, 1.12 g/cm 3 [18]. By chance, this value coincided with q tr measured in nitrogen for the product of post-crosslinking of St-0.3% DVB with MCDE to 100% (Table 2).…”

Crystallization kinetics of isotactic polystyrene. I. Spherulitic growth rate

“…This characteristic dependence on temperature of G for polymers has been found earlier for i-PS. [2][3][4] To show that i-PS is a slowly crystallizing polymer, the maximum values of G for some polymers (molecular weight about lOoO00), which were taken from the l i t e r a t~r e ,~-~~ are presented in Table 11. These values were measured directly or estimated from values found at other temperatures.…”

“…The growth rate has been measured by Kenyon et a1. 2 Keith and Padden3 have used i-PS, among others, to study impurity segregation during crystallization. Hay4 has examined the overall rate of crystallization.…”