Tomlins, P E; Richardson, M J (1999) The influence of phthalocyanin blue on the crystallization behaviour of polypropylene. NPL Report. CMMT(A)147

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Abstract

The crystallization kinetics from the melt of isotactic polypropylene either unpigmented or containing the organic pigment phthalocyanin blue (at concentrations of 0.1, 0.2 and 0.3%) have been studied using a combination of calorimetry and optical microscopy. The results show that the pigment acts as a nucleating agent, dramatically changing the crystallization behaviour of the polypropylene. At concentrations of 0.1 % the pigment substantially reduces the size of spherulites and significantly increases their number. Non-isothermal measurements show that the onset of crystallization for samples containing this concentration of pigment occurs some 160C higher than in the unpigmented material. The overall level of crystallization is unaffected by the addition of the pigment although the morphology of the spherulites changes from 2-d discs to 3-d spheres. The activation energy required for crystallization is essentially unaffected by phthalocyanin blue but the overall surface energy of the spherulites is lowered. This behaviour is consistent with that expected of a good nucleating agent.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	CMMT(A)147
Subjects:	Advanced Materials Advanced Materials > Polymers
Last Modified:	10 Sep 2018 14:09
URI:	http://eprintspublications.npl.co.uk/id/eprint/1088

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