Effect of rare earth β⁃nucleating agent on crystallization and foaming properties of polypropylene

doi:10.19491/j.issn.1001-9278.2024.12.005

Abstract

Abstract:

A variety of nucleating agents were introduced into long⁃chain branched polypropylene （LCBPP） to investigate the β⁃crystal nucleating effect of a nucleating agent WBG⁃Ⅱ in the LCBPP/isotactic polypropylene （iPP） blends as well as to evaluate their impact on the mechanical properties and foam structure of formed PP materials. The as⁃prepared samples were characterized by X⁃ray diffraction， differential scanning calorimetry， and rotational rheometer to identify the highly effective β⁃crystal inducer， WBG⁃Ⅱ. The results indicated that the addition of 5 phr WBG⁃Ⅱ resulted in an increase in the impact strength of LCBPP by 128 %， whereas its tensile strength decreased by above 20 %. Additionally， the nucleating agent had no significant adverse effect on the melt strength of LCBPP. Polarized optical microscopy （POM） observations further revealed that WBG⁃Ⅱ effectively induced the β⁃crystal orientation in iPP. Incorporating iPP into the LCBPP matrix significantly increased the β⁃crystal content in the blend. Compared to pure LCBPP， there was an increase in the crystallinity degree by 190 % for the LCBPP/iPP sample at a mas ratio of 1/1. Furthermore， the addition of iPP enhanced the storage modulus and complex viscosity of the PP blend under high⁃frequency conditions.

Key words: long?chain branched polypropylene, isotactic polypropylene, β?phase nucleating agent, supercritical carbon dioxide, microcellular foam

CLC Number:

TQ325.1⁺4

LIU Yaning, LIU Haiming, LIU Shao, CHEN Shihong, WANG Xiangdong. Effect of rare earth β⁃nucleating agent on crystallization and foaming properties of polypropylene[J]. China Plastics, 2024, 38(12): 29-36.

Figures/Tables 11

References 23

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样品编号	聚丙烯名称	聚丙烯牌号	成核剂牌号	聚丙烯含量/份	成核剂含量/份	抗氧剂含量/份
1^#	LCBPP	WB140	-	100	-	1
2^#		WB140	TMB⁃5	100	2.5	1
3^#		WB140	NU⁃100	100	2.5	1
4^#		WB140	WBG⁃Ⅱ	100	2.5	1
5^#	iPP	T30S	-	100	-	1
6^#		T30S	TMB⁃5	100	2.5	1
7^#		T30S	NU⁃100	100	2.5	1
8^#		T30S	WBG⁃Ⅱ	100	2.5	1

样品编号	聚丙烯名称	聚丙烯牌号	成核剂牌号	聚丙烯含量/份	成核剂含量/份	抗氧剂含量/份
1^#	LCBPP	WB140	-	100	-	1
2^#		WB140	TMB⁃5	100	2.5	1
3^#		WB140	NU⁃100	100	2.5	1
4^#		WB140	WBG⁃Ⅱ	100	2.5	1
5^#	iPP	T30S	-	100	-	1
6^#		T30S	TMB⁃5	100	2.5	1
7^#		T30S	NU⁃100	100	2.5	1
8^#		T30S	WBG⁃Ⅱ	100	2.5	1

样品编号	聚丙烯牌号	成核剂牌号	聚丙烯含量/份	成核剂含量/份	抗氧剂含量/份
9^#	WB140	WBG⁃Ⅱ	100	0	1
10^#	WB140	WBG⁃Ⅱ	100	0.25	1
11^#	WB140	WBG⁃Ⅱ	100	1.25	1
12^#	WB140	WBG⁃Ⅱ	100	2.5	1
13^#	WB140	WBG⁃Ⅱ	100	3.75	1
14^#	WB140	WBG⁃Ⅱ	100	5.0	1

样品编号	聚丙烯牌号	成核剂牌号	聚丙烯含量/份	成核剂含量/份	抗氧剂含量/份
9^#	WB140	WBG⁃Ⅱ	100	0	1
10^#	WB140	WBG⁃Ⅱ	100	0.25	1
11^#	WB140	WBG⁃Ⅱ	100	1.25	1
12^#	WB140	WBG⁃Ⅱ	100	2.5	1
13^#	WB140	WBG⁃Ⅱ	100	3.75	1
14^#	WB140	WBG⁃Ⅱ	100	5.0	1

样品编号	成核剂牌号	iPP含量/份	LCBPP 含量/份	成核剂含量/份	抗氧剂含量/份
15^#	WBG⁃Ⅱ	0	100	2.5	1
16^#	WBG⁃Ⅱ	10	90	2.5	1
17^#	WBG⁃Ⅱ	20	80	2.5	1
18^#	WBG⁃Ⅱ	30	70	2.5	1
19^#	WBG⁃Ⅱ	40	60	2.5	1
20^#	WBG⁃Ⅱ	50	50	2.5	1