What is a Liquid Crystal Polymer?
Liquid crystal polymers are a type of thermoplastic that have some liquid crystal properties, meaning that in some respects they behave like a crystal, and in other respects behave more like a liquid. An LCP yarn is one that been spun from the raw polymer.
Types of Liquid Crystal Polymer:
There are a variety of brands of liquid crystal polymer plastics available, including Vectra, Kevlar, Zenite, Zxion, Laperos, and Siveras. However, as yarns, only Vectran, which is made from Vectra, Kevlar, Zxion, and Siveras are available. This means that the selection of LCP yarns is relatively limited, compared to the range of aramid, carbon, and standard material yarns that are available on the market. Nonetheless, the LCP yarns that are available are very highly regarded for their properties, which are listed below.
Benefits of Liquid Crystal Polymer Yarns:
Liquid crystal polymer yarns, like Vectran, have a number of highly advantageous characteristics that can justify their cost. Liquid crystal polymer yarns have excellent tensile strength and tensile modulus ratings, which are broadly similar across the available brands of LCPs. Both are significantly higher than with standard yarns, like nylon and polyester. Resistance to harsh chemicals is also strong among liquid crystal polymer yarns; however, some are more resistant than others. The safe concentrations of chemicals and the exposure time without degradation both differ depending on the exact LCP yarn.
Uses of Liquid Crystal Polymer Yarns:
As with all technical and high-performance yarn types, liquid crystal polymer yarns have been used in a myriad of ways, including ending up in space. We’ve written before about how aramids, including Kevlar have been used in space exploration and particularly in landing science and exploration equipment onto the surface of Mars. Liquid Crystal Polymer yarns, specifically Vectran and Kevlar, have both been used in space exploration. Vectran has been used in three different and very interesting ways.
First, Vectran was relied on as the primary material in the over-sized airbags that landed three of NASA’s rovers on Mars: Sojourner, Spirit, and Opportunity. It was then used in the spacesuits worn by astronauts on the International Space Station. It was then also used to form the skin of a temporary inflatable module onboard the ISS, which has been in operation since 2016 and is expected to remain until 2018. These demanding and safety-critical applications of Vectran show the reliability and durability of liquid crystal polymers.
Back on earth, however, there are applications for LCPs like Vectran that we may use in our everyday lives. For example, some higher-end badminton racquets use vectran in their strings. In addition to badminton racquets, LCPs have been adopted by cycling for use on bicycle tires, where LCPs’ superior abrasion resistance increase the durability of bicycle tires, while ensuring that the mass of the bicycle tires remains minimal.
Additionally, LCP yarns can be used to make sailcloth for high performance sailing yachts; we have already written about the use of aramids like Kevlar in sails. Other LCPs, like Vectran, can be used to reinforce sailcloth made from more common materials like polyester and nylon, which can extend their lifespans.