Effects of molecular weight and molecular structure of low profile additives on the properties of Bulk Molding Compound (BMC).: An article from: Polymer Engineering and Science
Book Details
Publisher
Society of Plastics Engineers, Inc.
ISBN / ASIN
B0008DILHS
ISBN-13
978B0008DILH8
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Available for download now
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#12,874,587
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United States 🇺🇸
Description
This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on May 1, 2003. The length of the article is 3607 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
From the author: The effects of molecular weight and molecular structure of styrene(St)-based and vinyl acetate(VAc)-based low-profile additive (LPA) on the curing kinetics and compatibility of unsaturated polyester (UP)/LPA system and linear shrinkage, water absorption rate, surface gloss and pigmentability of bulk molding compound (BMC) were investigated. Results show that the curing reaction rate decreases with an increase of the molecular weight of LPA due to the chain entanglement effect. The plasticizing effect of LPA on the (UP) network was reduced with an increase of the molecular weight of LPA. Water absorption of BMC increases as the molecular weight of LPA increases, implying that more microvoids were formed inside the BMC, resulting a lower linear shrinkage rate, and worse pigmentability. However, good shrinkage control LPA does not necessarily lead to a smoother surface and better surface gloss. Furthermore, modified LPAs possess better compatibility with UP, the final curing conversion of UP is elevated, and bot h better shrinkage control and surface properties are also observed.
Citation Details
Title: Effects of molecular weight and molecular structure of low profile additives on the properties of Bulk Molding Compound (BMC).
Author: Chen-Chi M. Ma
Publication:Polymer Engineering and Science (Refereed)
Date: May 1, 2003
Publisher: Society of Plastics Engineers, Inc.
Volume: 43 Issue: 5 Page: 989(10)
Distributed by Thomson Gale
From the author: The effects of molecular weight and molecular structure of styrene(St)-based and vinyl acetate(VAc)-based low-profile additive (LPA) on the curing kinetics and compatibility of unsaturated polyester (UP)/LPA system and linear shrinkage, water absorption rate, surface gloss and pigmentability of bulk molding compound (BMC) were investigated. Results show that the curing reaction rate decreases with an increase of the molecular weight of LPA due to the chain entanglement effect. The plasticizing effect of LPA on the (UP) network was reduced with an increase of the molecular weight of LPA. Water absorption of BMC increases as the molecular weight of LPA increases, implying that more microvoids were formed inside the BMC, resulting a lower linear shrinkage rate, and worse pigmentability. However, good shrinkage control LPA does not necessarily lead to a smoother surface and better surface gloss. Furthermore, modified LPAs possess better compatibility with UP, the final curing conversion of UP is elevated, and bot h better shrinkage control and surface properties are also observed.
Citation Details
Title: Effects of molecular weight and molecular structure of low profile additives on the properties of Bulk Molding Compound (BMC).
Author: Chen-Chi M. Ma
Publication:Polymer Engineering and Science (Refereed)
Date: May 1, 2003
Publisher: Society of Plastics Engineers, Inc.
Volume: 43 Issue: 5 Page: 989(10)
Distributed by Thomson Gale
