Preparation of long⁃chain⁃branched poly（ethylene terephthalate） and its foaming properties by supercritical CO2 extrusion

doi:10.19491/j.issn.1001-9278.2023.11.001

Abstract

Abstract:

Long⁃chain⁃branched poly（ethylene terephthalate）（PET） was controllably prepared through reactive extrusion by a combination of in⁃situ polymerization of polyol⁃modified PET with a branched structure as a raw material and pyromellitic dianhydride （PMDA） as a chain extender. Rheological test results indicated that the melt viscoelasticity of long⁃chain⁃branched MPET was greatly improved， and its strain hardening factor was also enhanced with an increase in the long chain branched degree. During the supercritical CO₂ extrusion foaming process， the long⁃chain⁃branched modified MPET exhibited excellent extrusion foamability. The MPET foam prepared with 0.3 wt% PMDA （MPET⁃P3） presented the best extruded foaming performance， which obtained an expansion ratio of 14.0 at 265 °C， a cell density of 4.81×10⁶ cells/cm³， and an average cell diameter of 153.9 μm.

Key words: poly（ethylene terephthalate）, long?chain?branching, supercritical carbon dioxide, extrusion foaming, high expansion ratio

CLC Number:

TQ323.4

FENG Yingjian, HU Dongdong, WEI Shaolong, QIAN Jun, XIONG Wei, YAO Shun, ZHAO Ling. Preparation of long⁃chain⁃branched poly（ethylene terephthalate） and its foaming properties by supercritical CO₂ extrusion[J]. China Plastics, 2023, 37(11): 1-9.

Figures/Tables 14

样品名称	PET原料	PMDA/%	抗氧剂/%	特性黏度/dL∙g^-1
MPET⁃0	MPET	0	1	0.62
MPET⁃1	MPET	0.2	1	0.70
MPET⁃2	MPET	0.4	1	0.88
MPET⁃3	MPET	0.6	1	1.15
MPET⁃4	MPET	0.8	1	—
BPET⁃2	BPET	0.4	1	0.97

Tab.1. Formula of the samples

Fig.1. Schematic diagram of the two⁃stage extrusion foaming system［12］

Fig.2. FTIR spectra of the PET samples

Fig.3. Scheme of reaction mechanism of long⁃chain⁃branched PET

Fig.4. Rheological behavior of PET samples at 260 ℃ in the frequency range between 0.1 rad/s to 100 rad/s

Fig.5. Relaxation spectra of the PET samples

Fig.6. Elongational rheological behavior of the PET samples at different elongation rates

样品名称	0.1 s^-1	0.3 s^-1	0.5 s^-1
MPET⁃0	1.36	1.49	1.54
MPET⁃1	1.63	1.89	1.84
MPET⁃2	1.97	2.14	3.75
MPET⁃3	2.70	5.98	6.71
MPET⁃4	6.33	8.12	9.06

Tab.2. XE of PET samples at different stretching rates

Fig.7. SEM images of MPET⁃P2 at different temperature （×50）

Fig.8. Average cell diameter， cell density and expansion ratio of PET extrusion foams at different temperature

Fig.9. SEM images of MPET⁃P3 at different die temperature（×150）

Fig.10. SEM images of PET extrusion foams at 290 ℃（×100）

Fig.11. SEM images of BPET⁃P2 at different die temperature （×50）

Fig.12. Average cell diameter， cell density and expansion ratio of BPET⁃P2 extrusion foams at different temperature

References 19

1	Liu H， Antwi⁃Afari M F， Mi H， et al. Research on the feasibility of polyethylene terephthalate foam used in wind turbine blades［J］. Environmental Progress & Sustainable Energy， 2023， 42（1）：13956.
2	Garrido M， Correia J R， Keller T. Effects of elevated temperature on the shear response of PET and PUR foams used in composite sandwich panels［J］. Construction and Building Materials， 2015， 76：150⁃157.
3	Costas M， Morin D， Langseth M， et al. Axial crushing of aluminum extrusions filled with PET foam and GFRP. An experimental investigation［J］. Thin⁃Walled Structures， 2016， 99：45⁃57.
4	Yao S， Guo T， Liu T， et al. Good extrusion foaming performance of long⁃chain branched PET induced by its enhanced crystallization property［J］. Journal of Applied Polymer Science， 2020， 137（41）：49268.
5	Quintans J， Xanthos M， Dey S， et al. Melt viscoelasticity of polyethylene terephthalate resins for low density extrusion foaming［J］. Polymer Engineering & Science， 2000， 40（3）：554⁃566.
6	Bocz K， Molnár B， Marosi G， et al. Preparation of low⁃density microcellular foams from recycled pet modified by solid state polymerization and chain extension［J］. Journal of Polymers and the Environment， 2019， 27（2）：343⁃351.
7	Xanthos M， Dey S K， Zhang Q， et al. Parameters affecting extrusion foaming of PET by gas injection［J］. Journal of Cellular Plastics， 2000， 36（2）：102⁃111.
8	Bocz K， Ronkay F， Molnár B， et al. Recycled PET foaming： Supercritical carbon dioxide assisted extrusion with real⁃time quality monitoring［J］. Advanced Industrial and Engineering Polymer Research， 2021， 4（3）：178⁃186.
9	Fan C， Wan C， Gao F， et al. Extrusion foaming of poly（ethylene terephthalate） with carbon dioxide based on rheology analysis［J］. Journal of Cellular Plastics， 2016， 52（3）：277⁃298.
10	黄超. 以CO₂为发泡剂的聚酯PET挤出发泡过程［D］. 上海：华东理工大学， 2012.
11	Zhong H， Xi Z， Liu T， et al. In⁃situ polymerization⁃modification process and foaming of poly（ethylene terephthalate）［J］. Chinese Journal of Chemical Engineering， 2013， 21（12）：1 410⁃1 418.
12	Yao S， Chen Y， Ling Y， et al. Analysis of bubble growth in supercritical CO₂ extrusion foaming polyethylene terephthalate process based on dynamic flow simulation［J］. Polymers， 2021， 13（16）：2799.
13	Ge Y， Yao S， Xu M， et al. Improvement of poly（ethylene terephthalate） melt⁃foamability by long⁃chain branching with the combination of pyromellitic dianhydride and triglycidyl isocyanurate［J］. Industrial and Engineering Chemistry Research， 2019， 58（9）：3 666⁃3 678.
14	Park C P， Malone B A. Extruded closed⁃cell polypropylene foam： US，5527573A［P］. 1996⁃6⁃18.
15	Xu M， Lu J， Zhao J， et al. Rheological and foaming behaviors of long⁃chain branched polyamide 6 with controlled branch length［J］. Polymer， 2021， 224：123730.
16	Schweizer T. Structure and rheology of molten polymers［J］. Applied Rheology， 2007， 17（5）：258⁃259.
17	Yang Z， Xin C， Mughal W， et al. High⁃melt⁃elasticity poly（ethylene terephthalate） produced by reactive extrusion with a multi⁃functional epoxide for foaming［J］. Journal of Applied Polymer Science， 2018， 135（8）：45805.
18	Tabatabaei S H， Carreau P J， Ajji A. Rheological properties of blends of linear and long⁃chain branched polypropylenes［J］. Polymer Engineering & Science， 2010， 50（1）：191⁃199.
19	Chen P， Zhao L， Gao X， et al. Engineering of polybutylene succinate with long⁃chain branching toward high foamability and degradation［J］. Polymer Degradation and Stability， 2021， 194：109745.

[1]	JIAO Yang, WANG Longzhen, CAI Zhuorui, LIU Ronghao, ZHANG Yuxia, ZHOU Hongfu. Study on preparation and resilience of PBAT foams with high volume expansion ratio [J]. China Plastics, 2023, 37(9): 19-27.
[2]	LI Menglu, SU Tingting, WANG Zhanyong. Synthesis of PBAT through transesterification with discarded PET [J]. China Plastics, 2022, 36(9): 105-110.
[3]	JI Feng, GONG Weihua, ZHANG Yan, LUO Shuiyuan, YU Qingyu, ZHU Junqiu, GUO Jiangbin. Preparation of biodegradable PBAT foaming particles by supercritical carbon dioxide autoclave foaming technology [J]. China Plastics, 2022, 36(5): 122-126.
[4]	SONG Renda, WU Gaojian, CHEN Junxiang, ZHANG Youchen, YANG Weimin, XIE Pengcheng. Preparation and its electromagnetic shielding performance of PP/PET/CNTs foaming composites [J]. China Plastics, 2022, 36(2): 1-7.
[5]	WEN Jinsong. Market analysis of photovoltaic backsheets based on plastic films [J]. China Plastics, 2022, 36(12): 71-77.
[6]	QIAO Shize, GUO Menghao, HE Yadong, XIN Chunling. Solubility and diffusion behavior sof CO₂ in PPO and PS blends [J]. China Plastics, 2022, 36(10): 71-76.
[7]	XUE Yu, YIN Dexian, XIANG Lubing, ZHOU Yuan, YANG Xueyue, ZHOU Hongfu. Study on Microcellular Foaming Behavior of Chain⁃Extended Poly（butylene succinate） [J]. China Plastics, 2021, 35(8): 125-130.
[8]	YANG Wenjie, HE Jiawen, ZHU Hanbin, WANG Sisi, LI Xiping. Mechanical Properties and Foaming Behaviors of Graphene⁃reinforced Poly（lactic acid） [J]. China Plastics, 2021, 35(6): 26-32.
[9]	WANG Chenlei, HU Hao, QIAO Wenyu. Study on Poly（ethylene terephthalate） for 3D Printing [J]. China Plastics, 2021, 35(5): 24-31.
[10]	ZHANG Yihui, CHEN Shihong, WANG Conglong, WANG Xiangdong. Study on Polyetherimide Foaming Behavior under Homogeneous Nucleation [J]. China Plastics, 2021, 35(5): 65-71.
[11]	LIU Runqing, XING Mingming, HUANG Jiming. Study on Liquefaction Behavior of PET under Catalysis with Camellia Shell C⁃SO₃H Solid Acid [J]. China Plastics, 2021, 35(3): 105-111.
[12]	CAI Hengfang, SUN Ling. Molecular Dynamics Study on Effects of Temperature and Shear Rate on CO₂ Diffusion Behavior in Foaming Process of Injection Molding [J]. China Plastics, 2021, 35(3): 83-89.
[13]	WANG Duyang, CAI Zhennan, HUANG Xingyuan, WANG Long, LI Mengshan. Diffusion Coefficient of Supercritical Carbon Dioxide in Polystyrene Melt [J]. China Plastics, 2021, 35(2): 63-70.
[14]	Weina CAO, Yahao ZHAO, Mengjie ZHOU, Jingwen ZHAI, Xiang YU. Preparation and Properties of Hydrophilic PET Blends [J]. China Plastics, 2020, 34(8): 30-35.
[15]	Xiang YU, Ruyang LI, Jingwen ZHAI, Huanhuan TAN. Preparation and Properties of PET/PAAS/Activated Carbon Composites with Low VOC Content [J]. China Plastics, 2020, 34(6): 80-86.

Preparation of long⁃chain⁃branched poly（ethylene terephthalate） and its foaming properties by supercritical CO₂ extrusion

RichHTML

PDF

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 14

References 19

Related Articles 15

Recommended Articles

Metrics

Comments