Development of Crystalline Morphology, Structure, and Impact Property of Isotactic Polypropylene and Poly(cis-Butadiene) Rubber Blends During Mixing

Abstract

The development of crystalline morphology, structure, and impact property of isotactic polypropylene (PP) and poly(cis-butadiene) rubber (PcBR) (vol. % : 80/20) blends during mixing were investigated and compared to neat PP. It was found by polarized optical microscopy (POM) and small-angle light scatter (SALS) that the incorporation of PcBR into PP caused small and imperfect PP spherulites and more diffused spherulite boundaries, which sharply exhibited in the initial 2 min of mixing but remained almost unchanged in the rest of the mixing time. Crystalline structure of neat PP and blends was studied by wide-angle x-ray diffraction (WAXD). The addition of PcBR into PP induced formation of PP b-form spherulites. As mixing time developed, the relative degree of crystallization decreased whereas interplanar distance increased. Impact strength of PP and blends was tested. The result showed that impact strength of blends significantly improved with increase of the mixing time.

Characterisation of the thickness of transition layer and its relation to mechanical properties of polypropylene/poly(ethylene-co-octene) blends

“…(19) can be replaced by the correlation distance a c , which was the typical dimension of the dispersed phase and discussed in above section. Then Eq.…”

“…Defining the volume fraction of the transition layer as ϕ 3 , a modified expression of Eq. (5) can be given as follows [19]:…”

“…Several parameters (e.g., integral invariable Q, correlation distance a c and the radius of gyration R) were introduced in the traditional light scattering theory to express internal structural information of polymers. The small-angle laser light scattering (SALLS) system is one of the most widely used techniques for obtaining structural information, which is applied to study the phase structure and morphology of polymer blends by many researchers [15][16][17][18][19]. It is possible to characterize both microscopic and mesoscopic morphological variables in a single measurement, because SALLS provides a statistical evaluation of the shapes and sizes of scattering entities (particles or other morphological structure), and examines the morphologies which are not perfectly defined.…”

Effect of heterophasic or random PP copolymer on the compatibility mechanism between EVA and PP copolymers

“…In particular, the planes at 2θ = 17.3 and 18.7° are sharper in the case of PP‐EP. Some reports on PP‐poly butadiene rubber blends,35 indicate the formation of β‐form crystals influencing the PP mechanical behavior. In our case, it can be seen that both copolymers showed α crystals diffraction planes for isotactic PP.…”

Study of Micro-Injection Moulding: Factors Affecting the Content of the β-phase in Isotactic Polypropylene with β-nucleating Agent

“…Some special techniques can be used to obtain the iPP with relatively high levels of b-phase, such as the temperature gradient method [11] , flow-induced crystallization [12][13][14] and adding specific nucleating agent [15][16][17][18][19] . Among them, the addition of some b-nucleating agents is an efficient and accessible method to obtain the iPP with relatively high level of b-phase.…”